ospf sham link configuration

OSPF SHAM LINK. Then VPN traffic is transmitted through the route over the backbone network but not backdoor routes. The sham link is a logical link, similar to a virtual link. A CE router can then learn the routes to other sites in the VPN by peering with its attached PE router. Router2(config-if)# # rip 1 version 2 network 192.168.1. network 12.0.0.0 AR2 ip vpn-instance a Configure < Return to Cisco.com search results. For basic information about how to configure an MPLS VPN, refer to the "MPLS Virtual Private Networks Configuration" module. If you modify the metric value, routing loops may occur. A CE router can then learn the routes to other sites in the VPN by peering with its attached PE router. When the backbone network is running properly, VPN traffic of CE1 and CE2 should be forwarded over the MPLS backbone network without passing through the OSPF intra-area routes. Other thing to remember is that those loopbacks must be advertised by a protocol other than OPSF. In an MPLS VPN configuration, the OSPF cost configured with a sham-link allows you to decide if OSPF client site traffic will be routed over a backdoor link or through the VPN backbone. When the sham link is active, hello packets are . support. It is defined in RFC 1163. If no backdoor link exists between sites in the same area, you do not need to configure any OSPF sham link. What is MPLS Label distributing protocol (LDP) ? For these steps following commands are used respectively. Figure 1: OSPF Sham Link Use the remote-neighbor command to configure the OSPF sham link on both VRFs joined by the link. Customers Also Viewed These Support Documents. undo arp learning passive enable Passive ARP. Router1(config)# interface loopback interface-number, 5. Removes the IP address. If STP is enabled If a prefix is learned across the sham-link and the path via the sham-link is selected as the best, the PE router does not generate an MP-BGP update for the prefix. Complete basic BGP/MPLS IP VPN configuration on the backbone network: configure an IGP, enable MPLS and LDP, and establish an MP-IBGP peer relationship between the PEs. --customer edge router. CEF VPN process-id Although OSPF PE-CE connections assume that the only path between two client sites is across the MPLS VPN backbone, backdoor paths between VPN sites (shown in grey in the figure below) may exist. Table 1Feature Information for OSPF Sham-Link Support for MPLS VPN, IPv6 Routing: OSPFv3 Authentication Support with IPsec, OSPF Update Packet-Pacing Configurable Timers, Autoroute Announce and http://www.cisco.com/cisco/web/support/index.html. When a router ID has been found, the process stops. An Internet protocol used to exchange routing information within an autonomous system. areaarea-id % Only classful networks will be redistributed. No new or modified RFCs are supported by this feature. huawei netengine series router configuration guide ip routing ospf configuration ospf configuration about this chapter building ospf networks, you can enable . A sham-link is required between any two VPN sites that belong to the same OSPF area and share an OSPF backdoor link. Copyright 2022 Huawei Technologies Co., Ltd. All rights reserved. CE 1 and CE 2 are in the same OSPF area. A Sham links is required only between two VPN sites that belong to the same area and have a backdoor link for backup purposes. the backbone network. forwarding *> 192.168.40.1/32 10.1.1.2 2 32768 ? *>i 10.0.0.0 192.168.10.1 0 100 0 ? These routes are then propagated across other PEs using MP-BGP. OSPF Update Packet-Pacing Configurable Timers, OSPF Forwarding Address Suppression in Translated Type-5 LSAs, OSPF Inbound Filtering Using Route Maps with a Distribute List, OSPFv3 Fast Convergence: LSA and SPF Throttling, OSPF Mechanism to Exclude Connected IP Prefixes from LSA Advertisements, OSPF Limit on Number of Redistributed Routes, OSPF Support for Unlimited Software VRFs per PE Router, OSPF Link-State Database Overload Protection, OSPF MIB Support of RFC 1850 and Latest Extensions, OSPF Support for Forwarding Adjacencies over MPLS TE Tunnels, Configuring OSPF TTL Security Check and OSPF Graceful Shutdown, Area Command in Interface Mode for OSPFv2, OSPFv3 IPSec ESP Encryption and Authentication, IPv6 Routing: OSPFv3 Authentication Support with IPsec, Using a Sham-Link to Correct OSPF Backdoor Routing. may not support all the features documented in this module. OSPF Sham links is a logical inter-area link carried by the super backbone. Router (config)# router ospf process_ID Router (config-router)# network IP_network_# [wild card mask] Area Number area number. Why Cannot L2VPN Map Packets by 802.1p Priority? Configures Timer intervals configured, Hello 10, Dead 40, Wait 40, Index 2/2, retransmission queue length 0, number of retransmission 0, Last retransmission scan length is 0, maximum is 0, Last retransmission scan time is 0 msec, maximum is 0 msec, Sham Link OSPF_SL0 to address 111.5.5.5 is up. The PE router uses the information received from MP-BGP to set the ongoing label stack of incoming packets, and to decide to which egress PE router to label switch the packets. Because the sham-link is seen as an intra-area link between PE routers, an OSPF adjacency is created and database exchange (for the particular OSPF process) occurs across the link. If you modify the metric value, routing loops may occur. 10-30-2011 09:50 AM. S1720, S2700, S5700, and S6720 V200R011C10. The only entry within the BGP table is the MP-BGP update received from PE-3 (the egress PE router for the 10.3.1.7/32 prefix). Router2(config)# We configure the virtual-link between ABRs and we use the area virtual-link command. The Sham-link is an unnumbered point-to-point intra-area link and is advertised as . SPF IGP The documentation set for this product strives to use bias-free language. To obtain better user experience, upgrade the browser to the latest version. click on Add Template and search for vedge. PE-1 and enters interface configuration mode. PE router connected to the CE router collects all the routes in a VRF routing table based on the VRF applied to the incoming interface. --VPN routing and forwarding instance. In some cases where Providers deliverMPLSlinks to customer locations ,OSPFmay be used asCE-PErouting protocol. The reason the OSPF route is not redistributed to BGP on the PE is because the other end of the sham-link already redistributed the route to BGP and there is no need for duplication. Cisco Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature. An advanced Layer 3 IP switching technology. The OSPF intra-area path is preferred over the interarea path (over the MPLS VPN backbone) generated by the PE-1 router. Use these resources to familiarize yourself with the community: What is OSPF Sham Links? vrf Step 1: Configure one loopback each on PE1 & PE2 and make it member of VRF. The MPLS VPN superbackbone provides an additional level of routing hierarchy to interconnect the VPN sites running OSPF. To locate and download MIBs for selected platforms, Cisco IOS XE releases, and feature sets, use Cisco MIB Locator found at the following URL: Application of the Border Gateway Protocol in the Internet. You can see that However, as shown in bold in the next example, the VRF routing table shows that the selected path is learned via OSPF with a next hop of 10.2.1.38, which is the Vienna CE router. As shown in bold in this example, the loopback interface is learned via BGP from PE-2 and PE-3. Sham link must be configured on both sides. router 1. 1 Redistribute external type 1 routes 2 Redistribute external type 2 routes metric Metric for redistributed routes nssa-external Redistribute OSPF NSSA external routes route-map Route map reference R1(config-router-af)#$e ospf 11 vrf A-1 match internal external 1 external 2R1(config-router-af)#end, R1(config)#router ospf 11 vrf A-1R1(config-router)#redistribute bgp 6123subnetsR1(config-router)#end, R3(config)#router bgp 6123R3(config-router)#address-family ipv4 vrf A-2R3(config-router-af)#$e ospf 13 vrf A-2 match internal external 1 external 2R3(config-router-af)#end, (R3(config-router-af)#redistribute ospf 13 vrf A-2 match internal external 1 external 2)R3(config)#router ospf 13 vrf A-2R3(config-router)#redistribute bgp 6123subnetsR3(config-router)#end, BGP table version is 7, local router ID is 192.168.13.1. *>i 192.168.50.1/32 192.168.30.1 2 100 0 ? The example in this section is designed to show how a sham-link is used only to affect the OSPF intra-area path selection of the PE and CE routers. Router1(config-if)# display ap global configuration AP . A VPN client has three sites, each with a backdoor link. Method Status ProtocolFastEthernet0/0 10.1.1.1 YES manual up upSerial4/0 1.1.1.1 YES manual up upSerial4/2 3.3.3.2 YES manual up upLoopback0 192.168.10.1 YES manual up upLoopback1 192.168.11.1 YES manual up upLoopback2 192.168.12.1 YES manual up upLoopback3 192.168.13.1 YES manual up up, Interface IP-Address OK? For the most current information, go to the Cisco Feature Navigator home page at the following URL: No new or modified standards are supported by this feature. Cisco IOS IP Routing: OSPF Command Reference, Cisco IOS master command list, all releases, Cisco IOS Master Command List, All Releases. *> 30.0.0.0 0.0.0.0 0 32768 ? vrf external Redistribute OSPF external routes internal Redistribute OSPF internal routes nssa-external Redistribute OSPF NSSA external routesR1(config-router-af)#redistribute ospf 11 vrf A-1 match internal ? PE1 interface Loopback1 vrf forwarding shamlink ip address 2.2.2.2 255.255.255.255 PE2 interface Loopback1 vrf forwarding shamlink interface. the IP address of the loopback interface on PE-1. DoNotAge LSA allowed. View with Adobe Reader on a variety of devices. loopback interfaces specified by the IP addresses as endpoints. Assign area IDs to be associated with the range of IP addresses. This community information is used by the receiving PE router to decide the type of link-state advertisement (LSA) to be generated when the BGP route is redistributed to theOSPF PE-CEprocess. Learn more about how Cisco is using Inclusive Language. Access to most tools on the Cisco Support and Documentation website requires a Cisco.com user ID and password. This module describes how to configure and use a sham-link to connect Virtual Private Network (VPN) client sites that run the Open Shortest Path First (OSPF) protocol and share backdoor OSPF links in a Multiprotocol Label Switching (MPLS) VPN configuration. https://lnkd.in/eNsfFGt #ccnacertification #ccnatraining #ccna #ccnp #ccie #cisco #cisconetworking #ciscogateway #ospf #shamlink. Find answers to your questions by entering keywords or phrases in the Search bar above. number. OSPF is often used by customers that run OSPF as their intrasite routing protocol, subscribe to a VPN service, and want to exchange routing information CEF optimizes network performance and scalability for networks with large and dynamic traffic patterns. After the configuration is complete, run the display ip routing-table vpn-instance command on the PEs. When the backdoor link is not enabled between the CE1 and CE2 the path followed from CE1 to CE2 is via MPLS backbone as shown below , Last update from 9.9.12.2 on FastEthernet0/0, 00:00:10 ago, * 9.9.12.2, from 9.9.12.2, 00:00:10 ago, via FastEthernet0/0 #Known via R2#, Route metric is 3, traffic share count is 1, VRF info: (vrf in name/id, vrf out name/id), 2 9.9.23.3 [MPLS: Labels 17/16 Exp 0] 96 msec 56 msec 76 msec, 3 9.9.45.4 [MPLS: Label 16 Exp 0] 84 msec 80 msec 56 msec. configures the OSPF cost for sending an IP packet on the PE-2 sham-link - Rashmi Bhardwaj (Author/Editor), For Sponsored Posts and Advertisements, kindly reach us at: ipwithease@gmail.com, Routing entry for 9.9.0.5/32Known via ospf 1, distance 110, metric 3, type inter area, Type escape sequence to abort.Tracing the route to 9.9.0.5, Routing entry for 9.9.0.5/32Known via ospf 1, distance 110, metric 2, type intra area, router ospf 1 vrf shamlinkarea 0 sham-link 2.2.2.2 4.4.4.4 cost 1, Sham Link OSPF_SL0 to address 4.4.4.4 is up, BGP routing table entry for 2:2:9.9.0.1/32, version 61, Copyright AAR Technosolutions | Made with in India, How to Replace a vEdge Router via vManage: Cisco Viptela SDWAN, Salesforce Security Best Practices for Keeping Your Data Protected, Technology in the Medical Field to Look Out for in 2023, What is DDoS Attack? area enters interface configuration mode. If the backdoor links between sites are used only for backup purposes and do not participate in the VPN service, then the default route selection shown in the preceding example is not acceptable. Within BGP, the locally generated route (10.2.1.38) is considered to be the best route. Associate the sham-link with an existing OSPF area. As a result, the desired intra-area connectivity is created. A broadcast packet used by link-state protocols. The section, "Creating a Sham-Link", describes how to configure a sham-link between two PE routers. interface Timer intervals configured, Hello 10, Dead 40, Wait 40, Index 2/2, retransmission queue length 0, number of retransmission 0, Last retransmission scan length is 0, maximum is 0, Last retransmission scan time is 0 msec, maximum is 0 msec, Paths: (1 available, best #1, table shamlink), Origin incomplete, metric 2, localpref 100, weight 32768, valid, sourced, best, Extended Community: RT:2:1OSPF DOMAIN ID:0x0005:0x000000010200, OSPF RT:0.0.0.0:2:0 OSPF ROUTER ID:9.9.12.2:0, 2 9.9.23.3 [MPLS: Labels 17/27 Exp 0] 84 msec 44 msec 68 msec, 3 9.9.45.4 [MPLS: Label 27 Exp 0] 68 msec 28 msec 68 msec, Known via ospf 1, distance 110, metric 4, type intra area, Last update from 9.9.12.2 on FastEthernet0/0, 00:00:56 ago, * 9.9.12.2, from 9.9.0.5, 00:00:56 ago, via FastEthernet0/0Known via R2#, Route metric is 4, traffic share count is 1, OSPF Multi-Area Adjacency : Example Scenario, I am here to share my knowledge and experience in the field of networking with the goal being - "The more you share, the more you learn." The LSA contains information about neighbors and path costs and is used by the receiving router to maintain a routing table. To obtain lists of supported MIBs by platform and Cisco IOS release, and to download MIB modules, go to the Cisco MIB website on Cisco.com at the following URL: http://www.cisco.com/public/sw-center/netmgmt/cmtk/mibs.shtml. A sham-link ensures that OSPF client sites that share a backdoor link can communicate over the MPLS VPN backbone and participate in VPN services. Last update from 9.9.15.5 on FastEthernet1/0, 00:00:01 ago, * 9.9.15.5, from 9.9.0.5, 00:00:01 ago, via FastEthernet1/0 #Known VIA R5 now#, Route metric is 2, traffic share count is 1. external Redistribute OSPF external routes metric Metric for redistributed routes nssa-external Redistribute OSPF NSSA external routes route-map Route map reference R1(config-router-af)#redistribute ospf 11 vrf A-1 match internal external ? The OSPF sham-link is used only to influence intra-area path selection. enters interface configuration mode. the features documented in this module, and to see a list of the releases in Bug Search Tool and the It is also generated through redistribution into BGP on PE-1. root@R8# run show ospf database instance CE1 OSPF database, Area 0.0.0.0 Type ID Adv Rtr Seq Age Opt Cksum Len Router 172.16.1.1 172.16.1.1 0x80000006 377 0x22 0x5133 72 Router *172.30.5.37 172.30.5.37 0x80000004 2202 0x22 0x3eae 48 . The sham link is an unnumbered point-to-point link inside a routing-instance between two PE routers. I am a biotechnologist by qualification and a Network Enthusiast by interest. vrf-name, 9. A Sham links is required only between two VPN sites that belong to the same area and have a backdoor link for backup purposes. If you've already registered, sign in. 5 nog r ng an OSPF Sham Link This section describes how to c nog r an OSPF sham link so that r oc between sites of the same VPN in the same OSPF area is forwarded through the OSPF . !Success rate is 100 percent (5/5), round-trip min/avg/max = 4/46/100 ms, R5(config)#router ospf 1R5(config-router)#network 192.168.50.0 255.0.0.0 area 0R5(config-router)#network 10.0.0.0 0.255.255.255 area 0R5(config-router)#endR3(config)#router ospf 13 vrf A-2R3(config-router)#network 30.0.0.0 0.255.255.255 area 0R3(config-router)#end*Mar 20 00:28:16.623: %OSPF-5-ADJCHG: Process 13, Nbr 192.168.50.1 on FastEthernet0/0 from LOADING to FULL, Loading Done, R3#show ip ospf13neighborNeighbor ID Pri State Dead Time Address Interface192.168.50.1 1 FULL/DR 00:00:33 30.1.1.2 FastEthernet0/0R3#show ip route vrfA-2ospfRouting Table: A-2Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 E1 - OSPF external type 1, E2 - OSPF external type 2 i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2 ia - IS-IS inter area, * - candidate default, U - per-user static route o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP + - replicated route, % - next hop overrideGateway of last resort is not set 192.168.50.0/32 is subnetted, 1 subnetsO 192.168.50.1 [110/2] via 30.1.1.2, 00:01:24, FastEthernet0/0, R1(config)#router bgp 6123R1(config-router)#no bgp default ipv4-unicastR1(config-router)#neighbor 192.168.30.1 remote-as 6123R1(config-router)#neighbor 192.168.30.1 update-source loopback 0R1(config-router)#address-family vpnv4 unicastR1(config-router-af)#neighbor 192.168.30.1 activateR1(config-router-af)#neighbor 192.168.30.1 send-community extendedR1(config-router-af)#neighbor 192.168.30.1 next-hop-selfR1(config-router-af)#end, R3(config)#router bgp 6123R3(config-router)#no bgp default ipv4-unicastR3(config-router)#neighbor 192.168.10.1 remote-as 6123R3(config-router)#neighbor 192.168.10.1 update-source loopback 0R3(config-router)#address-family vpnv4 unicastR3(config-router-af)#neighbor 192.168.10.1 activateR3(config-router-af)#neighbor 192.168.10.1 send-community extendedR3(config-router-af)#neighbor 192.168.10.1 next-hop-selfR3(config-router-af)#end, *Mar 20 00:59:36.259: %BGP-5-ADJCHANGE: neighbor 192.168.10.1 Up, R1(config)#router bgp 6123R1(config-router)#address-family ipv4 vrf A-1R1(config-router-af)#redistribute ospf 11 vrf A-1 match ? Router1(config)# Finding Feature Information Feature Overview Supported Platforms This example is designed to show how a sham-link is used only to affect the OSPF intra-area path selection of the PE and CE routers. For example, the figure above shows three client sites, each with backdoor links. method is to set the cost of the forwarding interface on the customer network to be larger than the cost of the sham link. Each task in the list is identified as either required or optional. The PE router uses the information received from MP-BGP to set the ongoing label stack of incoming packets, and to decide to which egress PE router to label switch the packets. Run the display ip routing-table command on a CE, and you can see that the cost of the OSPF route to the remote CE has changed to 3, and the next hop has changed to the VLANIF interface connected to the PE. All rights reserved. PE This link is called a sham-link. No relevant resource is found in the selected language. release notes for your platform and software release. *>i192.168.40.1/32 192.168.10.1 2 100 0 ? Glimpse of "EIGRP name mode configuration", Understanding Wireless Client Authentication, configure the topology as per the diagram, assign the IP addresses to their interfaces, configure IGP (OSPF 1) inside MPLS SP core, configure labels (99-199_200-299_300-399), configure VRF A-1 on router 1 and VRF A-2 on router 3, configure RD and RT value 500:1 on both the sites, configure on router 1 assign fastethernet facing CE under VRF A-1, configure on router 3 assign fastethernet facing CE under VRF A-2, Configure the loopbacks with exact mask to exchange the routes, configure OSPF 11 on PE router 1 under VRF A-1 and OSPF 13 on PE router 3 under VRF A-2. MPLS A VPN contains geographically dispersed sites that can communicate securely over a shared backbone. An Internet protocol used to exchange routing information within an autonomous system. Device(config-router-af)# area 1 virtual-link 1.1.1.1 authentication key-chain ospf-chain-1: Configures the authentication for virtual links. The figure below shows a sample sham-link between PE-1 and PE-2. To reestablish the desired path selection over the MPLS VPN backbone, you must create an additional OSPF intra-area (logical) link between ingress and egress VRFs on the relevant PE routers. After the configuration is complete, run the display ip routing-table vpn-instance command on the PEs. Perform the following steps on the PE devices at both ends of a sham link. BGP routing-table rib-only BGPIP. Step 9: area area-id sham-link source-address destination-address authentication key-chain chain-name. Configure VPN instances on PEs and bind the interfaces connected to CEs to the VPN instances. The figure below shows a sample sham-link between PE-1 and PE-2. An error occurred when loading the video. The syntax to configure sham-link is. Method Status Protocol, FastEthernet0/0 20.1.1.1 YES manual up up, Serial4/0 1.1.1.2 YES manual up up, Serial4/1 2.2.2.1 YES manual up up, Loopback0 192.168.20.1 YES manual up up, Loopback1 192.168.21.1 YES manual up up, Loopback2 192.168.22.1 YES manual up up, Loopback3 192.168.23.1 YES manual up up, FastEthernet0/0 30.1.1.1 YES manual up up, Serial4/1 2.2.2.2 YES manual up up, Serial4/2 3.3.3.1 YES manual up up, Loopback0 192.168.30.1 YES manual up up, Loopback1 192.168.31.1 YES manual up up, Loopback2 192.168.32.1 YES manual up up, Loopback3 192.168.33.1 YES manual up up, FastEthernet0/0 30.1.1.2 YES manual up up, Loopback0 192.168.40.1 YES manual up up, FastEthernet0/0 10.1.1.2 YES manual up up, Loopback0 192.168.50.1 YES manual up up, R1(config-router)#network 1.0.0.0 0.255.255.255 area 0, R1(config-router)#network 3.0.0.0 0.255.255.255 area 0, R1(config-router)#network 192.168.10.0 255.0.0.0 area 0, R1(config-router)#network 192.168.11.0 255.0.0.0 area 0, R1(config-router)#network 192.168.12.0 255.0.0.0 area 0, R1(config-router)#network 192.168.13.0 255.0.0.0 area 0, R2(config-router)#network 20.0.0.0 0.255.255.255 area 0, R2(config-router)#network 1.0.0.0 0.255.255.255 area 0, R2(config-router)#network 2.0.0.0 0.255.255.255 area 0, R2(config-router)#network 192.168.20.0 255.0.0.0 area 0, R2(config-router)#network 192.168.21.0 255.0.0.0 area 0, R2(config-router)#network 192.168.22.0 255.0.0.0 area 0, R2(config-router)#network 192.168.23.0 255.0.0.0 area 0, R3(config-router)#network 2.0.0.0 0.255.255.255 area 0, R3(config-router)#network 3.0.0.0 0.255.255.255 area 0, R3(config-router)#network 192.168.30.0 255.0.0.0 area 0, R3(config-router)#network 192.168.31.0 255.0.0.0 area 0, R3(config-router)#network 192.168.32.0 255.0.0.0 area 0, R3(config-router)#network 192.168.33.0 255.0.0.0 area 0, Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP, D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area, N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2, E1 - OSPF external type 1, E2 - OSPF external type 2, i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area, * - candidate default, U - per-user static route, o - ODR, P - periodic downloaded static route, H - NHRP, l - LISP, + - replicated route, % - next hop override, O 2.0.0.0/8 [110/128] via 3.3.3.1, 01:14:38, Serial4/2, [110/128] via 1.1.1.2, 01:14:38, Serial4/0, O 20.0.0.0/8 [110/65] via 1.1.1.2, 01:14:38, Serial4/0, O 192.168.20.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0, O 192.168.21.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0, O 192.168.22.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0, O 192.168.23.1 [110/65] via 1.1.1.2, 01:14:38, Serial4/0, O 192.168.30.0/24 [110/65] via 3.3.3.1, 01:14:38, Serial4/2, O 192.168.31.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2, O 192.168.32.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2, O 192.168.33.1 [110/65] via 3.3.3.1, 01:14:38, Serial4/2, O 1.0.0.0/8 [110/128] via 3.3.3.2, 01:18:05, Serial4/2, [110/128] via 2.2.2.1, 01:18:05, Serial4/1, O 20.0.0.0/8 [110/65] via 2.2.2.1, 01:18:05, Serial4/1, O 192.168.10.0/24 [110/65] via 3.3.3.2, 01:18:05, Serial4/2, O 192.168.11.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2, O 192.168.12.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2, O 192.168.13.1 [110/65] via 3.3.3.2, 01:18:05, Serial4/2, O 192.168.20.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1, O 192.168.21.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1, O 192.168.22.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1, O 192.168.23.1 [110/65] via 2.2.2.1, 01:18:05, Serial4/1, R1(config)#mpls label protocol ldpR1(config)#mpls label range 99 199R1(config)#mpls ldp router-id loopback 0R1(config)#exitR1(config)#interface serial 4/0R1(config-if)#mpls ipR1(config-if)#exitR1(config)#interface serial 4/2R1(config-if)#mpls ipR1(config-if)#exit, R2(config)#mpls label protocol ldpR2(config)#mpls label range 200 299R2(config)#mpls ldp router-id loopback 0R2(config)#exitR2(config)#interface serial 4/0R2(config-if)#mpls ipR2(config-if)#exitR2(config)#interface serial 4/1R2(config-if)#mpls ipR2(config-if)#exitR3(config)#mpls label protocol ldpR3(config)#mpls label range 300 399R3(config)#mpls ldp router-id loopback 0R3(config)#exit, R3(config)#interface serial 4/1R3(config-if)#mpls ipR3(config-if)#exitR3(config)#interface serial 4/2R3(config-if)#mpls ipR3(config-if)#exit, R1#show mpls ldp neighbor Peer LDP Ident: 192.168.20.1:0;Local LDP Ident 192.168.10.1:0 TCP connection: 192.168.20.1.41723 - 192.168.10.1.646 State: Oper; Msgs sent/rcvd: 190/188; Downstream Up time: 02:23:12 LDP discovery sources: Serial4/0, Src IP addr: 1.1.1.2 Addresses bound to peer LDP Ident: 20.1.1.1 1.1.1.2 2.2.2.1 192.168.20.1 192.168.21.1 192.168.22.1 192.168.23.1 Peer LDP Ident: 192.168.30.1:0;Local LDP Ident 192.168.10.1:0 TCP connection: 192.168.30.1.27403 - 192.168.10.1.646 State: Oper; Msgs sent/rcvd: 186/184; Downstream Up time: 02:20:31 LDP discovery sources: Serial4/2, Src IP addr: 3.3.3.1 Addresses bound to peer LDP Ident: 2.2.2.2 3.3.3.1 192.168.30.1 192.168.31.1 192.168.32.1 192.168.33.1, Peer LDP Ident: 192.168.10.1:0; Local LDP Ident 192.168.20.1:0, TCP connection: 192.168.10.1.646 - 192.168.20.1.41723, State: Oper; Msgs sent/rcvd: 189/192; Downstream, 1.1.1.1 3.3.3.2 192.168.10.1 192.168.11.1, Peer LDP Ident: 192.168.30.1:0; Local LDP Ident 192.168.20.1:0, TCP connection: 192.168.30.1.64637 - 192.168.20.1.646, State: Oper; Msgs sent/rcvd: 187/189; Downstream, 2.2.2.2 3.3.3.1 192.168.30.1 192.168.31.1, Peer LDP Ident: 192.168.20.1:0;Local LDP Ident 192.168.30.1:0, TCP connection: 192.168.20.1.646 - 192.168.30.1.64637, State: Oper; Msgs sent/rcvd: 190/188; Downstream, 20.1.1.1 1.1.1.2 2.2.2.1 192.168.20.1, 192.168.21.1 192.168.22.1 192.168.23.1, Peer LDP Ident: 192.168.10.1:0; Local LDP Ident 192.168.30.1:0, TCP connection: 192.168.10.1.646 - 192.168.30.1.27403, % Interface FastEthernet0/0 IPv4 disabled and address(es) removed due to enabling VRF A-1, R1(config-if)#ip address 10.1.1.1 255.0.0.0, % Interface FastEthernet0/0 IPv4 disabled and address(es) removed due to enabling VRF A-2, R3(config-if)#ip address 30.1.1.1 255.0.0.0, R1#show run | section vrfip vrf A-1rd 500:1route-target export 500:1route-target import 500:1ip vrf forwarding A-1, R1(config)#interface loopback 0R1(config-if)#ip ospf network point-to-pointR1(config-if)#end, R3(config)#interface loopback 0R3(config-if)#ip ospf network point-to-pointR3(config-if)#end, R4(config)#router ospf 1R4(config-router)#network 192.168.40.0 255.0.0.0 area 0R4(config-router)#network 30.0.0.0 0.255.255.255 area 0R4(config-router)#end, R1(config-router)#network 10.0.0.0 0.255.255.255 area 0, *Mar 20 00:18:20.379: %OSPF-5-ADJCHG: Process 11, Nbr 192.168.40.1 on FastEthernet0/0 from LOADING to FULL, Loading Done, Neighbor ID Pri State Dead Time Address Interface, 192.168.33.1 0 FULL/ - 00:00:33 3.3.3.1 Serial4/2, 192.168.23.1 0 FULL/ - 00:00:38 1.1.1.2 Serial4/0, 192.168.40.1 1 FULL/DR 00:00:33 10.1.1.2 FastEthernet0/0, O 192.168.40.1 [110/2] via 10.1.1.2, 00:01:43, FastEthernet0/0, R1#ping vrf A-1 192.168.40.1Type escape sequence to abort.Sending 5, 100-byte ICMP Echos to 192.168.40.1, timeout is 2 seconds:!!!! A router that is part of a service provider network connected to a customer edge (CE) router. which each feature is supported, see the feature information table. Areaarea-idsham-linksource-address destination-addresscostnumber. --provider edge router. In this way, internal OSPF routes that belong to the same VPN and are advertised over the VPN backbone are seen as interarea routes on the remote sites. cost number configures the OSPF cost for sending an IP packet on the PE-1 sham-link interface. Emerging industry standard upon which tag switching is based. How to configure MPLS L3 with BGP AS OVERRIDE? The only entry within the BGP table is the MP-BGP update received from PE-3 (the egress PE router for the 10.3.1.7/32 prefix). What they are, how they work, and why we need them. The figure below shows an example of how VPN client sites that run OSPF can connect over an MPLS VPN backbone. Reconfigures Before you create a Procedure Configure an endpoint address for the sham link. address When a sham-link is configured between PE routers, the PEs can populate the VRF routing table with the OSPF routes learned over the sham-link. What is MPLS Label distributing protocol (LDP) ? the data sent from CE1 to CE2 passes through the VLANIF interface connected to PE1. This blog post walks through the problem and the solution, including the configuration steps to create and verify a sham-link. Two sham-links have been configured, one between PE-1 and PE-2, and another between PE-2 and PE-3. The PE router can then flood LSAs between sites from across the MPLS VPN backbone. display ospf sham-link; display ospf spf-statistics; display ospf statistics updated-lsa; display ospf vlink; dn-bit-set; dn-bit-check; domain-idOSPF . interface-number, 3. Use Cisco Feature 2022 Cisco and/or its affiliates. address for other sham-links. cost Bug Search Tool and the vrf-name, 12. Sham Linkcan be created using two loopbacks on the respective devices advertised into the BGP address family that corresponds with the customerVRF. VRF A commonly used In an MPLS VPN configuration, the OSPF protocol is one way you can connect customer edge (CE) routers to service provider edge (PE) routers in the VPN backbone. Run the display ospf routing command on the CEs. Router2(config)# interface loopback interface-number, 11. Set the cost value of the forwarding interface of the private network to be larger than the cost of the sham link so that VPN traffic is transmitted over the MPLS backbone network. Router1# The following example shows BGP routing table entries for the prefix 10.3.1.7/32 in the PE-1 router in the figure above. When an OSPF sham-link is set it builds a bridge between two VRF's. By advertising a type 1 LSA (Router) across this link, the OSPF database sees this route and the routes advertised across this link as acceptable. Run the display ospf sham-link area command. The following table provides release information about the feature or features described in this module. Router CE1 and Router CE2 are located in the same OSPFv2 area. arp broadcast enable ARP. sham-link with an existing OSPF area. Cost of the OSPF route from CE1 to CE2 = Cost of the path from CE1 to PE1 + Cost of the sham link + Cost of the path from PE2 to CE2 = 1 + 1 + 1 = 3. vrf specified OSPF process with the VRF associated with the sham-link interface on Cost of using 1 State POINT_TO_POINT. Configures the How LDP works? BGP On the vManage GUI, click on Configuration => Templates and go to the Feature tab. If these sites belong to the same OSPF area, the path over a backdoor link will always be selected because OSPF prefers intraarea paths to interarea paths. --link-state advertisement. r RIB-failure, S Stale, m multipath, b backup-path, f RT-Filter. . This community information is used by the receiving PE router to decide the type of link-state advertisement (LSA) to be generated when the BGP route is redistributed to the OSPF PE-CE process. This document describes how to configure and use a sham-link to connect Virtual Private Network (VPN) client sites that run the Open Shortest Path First (OSPF) protocol and share backdoor OSPF links in a Multiprotocol Label Switching (MPLS) VPN configuration. We can do this with the OSPF sham link. Hi Arun, I would rather call the OSPF sham-link a special type of virtual link established over a targeted OSPF session, with additional rules governing the OSPF/BGP redistribution and allowing you to set the cost of the virtual link manually. Configure one serial link (backup link /backdoor) between router 4/5. As a result, Figure 4-53 Networking diagram for configuring an OSPF sham link Configuration Roadmap The configuration roadmap is as follows: Establish an ME-IBGP peer relationship between the PEs and configure OSPF between the PEs and CEs. It is not possible to route traffic from one sham-link over another sham-link. OSPF has a lower administrative distance (AD) than internal BGP (BGP running between routers in the same autonomous system). source-address Cisco IOS XE MPLS Configuration Guide, Release 2. A router that is part of a customer network and that interfaces to a provider edge (PE) router. MPLS For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. This video demonstrates configuration a DMVPN Hub and Spoke in Phase 3 Configuration.It confirms Phase 3 connectivity between 2 Spokes and Hub to Spoke Conf. A VPN contains geographically dispersed sites that can communicate securely over a shared backbone. R4(config-if)#ip address 30.1.1.2 255.0.0.0, R4(config-if)#ip address 192.168.40.1 255.255.255.0, R5(config-if)#Ip address 10.1.1.2 255.0.0.0, R5(config-if)#Ip address 192.168.50.1 255.255.255.0, R1#show ip interface briefInterface IP-Address OK? Advertise these lo1 addresses in IPV4 BGP as follows: Configure sham-link between PE1 and PE2 using lo1 IP addresses: Note while configuring you will need to ensure the cost of link between CE1 and CE2 always remain higher than that mentioned over Sham-link so that path through sham-link remains the preferred one. Router1(config-if)# For the purposes of this documentation set, bias-free is defined as language that does not imply discrimination based on age, disability, gender, racial identity, ethnic identity, sexual orientation, socioeconomic status, and intersectionality. configure VPNv4 peering between PE routers. --Multiprotocol Label Switching. --provider edge router. --link-state advertisement. *> 10.0.0.0 0.0.0.0 0 32768 ? How LDP works? configuration mode on the second PE router. A VPN client has three sites, each with a backdoor link. --customer edge router. number, 13. Examples of common IGPs include IGRP, OSPF, and RIP. It is defined in RFC 1163. The command output shows that the neighbor relationship is in Full state. loopback interface with a VRF. However, as shown in bold in the next example, the VRF routing table shows that the selected path is learned via OSPF with a next hop of 10.2.1.38, which is the Vienna CE router. For example, the figure above shows three client sites, each with backdoor links. ip A cost is configured with each sham-link and is used to decide whether traffic will be sent over the backdoor path or the sham-link path. 2022 Cisco and/or its affiliates. Your browser version is too early. No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. As shown in bold in this example, the loopback interface is learned via BGP from PE-2 and PE-3. In the following example, PE-2 shows how an MP-BGP update for the prefix is not generated. support. Establish an ME-IBGP peer relationship between the PEs and configure OSPF between the PEs and CEs. Router1(config)# basic bgp configuration # config router bgp set as 65100 set router-id 172.16.1.3 config neighbor edit "10.3.1.254" set remote-as 65200 next end config network edit 1 set prefix 10.1.0.0 255.255.255. protocol redistribution . The figure below shows an example of how VPN client sites that run OSPF can connect over an MPLS VPN backbone. To begin, MPLS is set up in the network as shown with R2 and R4 acting as Provider Edge (PE) routers, and MPLS is enabled throughout R2-R3-R4. Learn more about how Cisco is using Inclusive Language. Creates a A secure IP-based network that shares resources on one or more physical networks. Associates the loopback interface with a VRF. DoNotAge LSA allowed. To verify that the sham-link was successfully created and is operational, use the show ip ospf sham-links command in EXEC mode: Displays the operational status of all sham-links configured for a router. How to configure MPLS L3 VPN with EIGRP ? The reason the OSPF route is not redistributed to BGP on the PE is because the other end of the sham-link already redistributed the route to BGP and there is no need for duplication. ip The figure below shows a sample MPLS VPN topology in which a sham-link configuration is necessary. I am a strong believer of the fact that "learning is a constant process of discovering yourself." ip The PE routers that attach to the VPN use the Border Gateway Protocol (BGP) to distribute VPN routes to each other. Displays information about how the sham-link is advertised as an unnumbered point-to-point connection between two PE routers. The information displayed on CE1 is used as an example. It is also generated through redistribution into BGP on PE-1. Configuring an OSPF sham link Network requirements As shown in Figure 75, CE 1 and CE 2 belong to VPN 1. The OSPF costs loopback interfaces specified by the IP addresses as endpoints. loopback When sending traffic to a particular destination, the PE router uses the MP-BGP forwarding information. If these sites belong to the same OSPF area, the path over a backdoor link will always be selected because OSPF prefers intraarea paths to interarea paths. The "transit area" cannot . router In an MPLS VPN configuration, the OSPF protocol is one way you can connect customer edge (CE) routers to service provider edge (PE) routers in the VPN backbone. of all interfaces are 1. To configure a Sham-link we need one /32 loopback interface configured in each PE router under the particular VRF (vrf A in this lab). ring network, an interface on the network will be blocked. For the latest The following example shows how to configure a sham-link between two PE routers: BGP vrf-name, 14. Two sham-links have been configured, one between PE-1 and PE-2, and another between PE-2 and PE-3. Router1(config-if)# ip vrf forwarding vrf-name, 6. 1. When OSPF is used as a protocol between PE and CE routers, the OSPF metric is preserved when routes are advertised over the VPN backbone. -- Router1(config)# router ospf process-id vrf vrf-name, 16. You can change lines. router Associates the and connected interfaces are removed from VLAN 1. To configure a static route between the PE and the CE routers, include the static statement: content_copy zoom_out_map. Configure redistribution on PE routers between OSPF and BGP under VRF. Associate the lets see the configuration for better understanding:-, R1(config-if)#Ip address 10.1.1.1 255.0.0.0, R1(config-if)#Ip address 1.1.1.1 255.0.0.0, R1(config-if)#Ip address 3.3.3.2 255.0.0.0, R1(config-if)#Ip address 192.168.10.1 255.255.255.0, R1(config-if)#Ip address 192.168.11.1 255.255.255.0, R1(config-if)#Ip address 192.168.12.1 255.255.255.0, R1(config-if)#Ip address 192.168.13.1 255.255.255.0, R2(config-if)#Ip address 20.1.1.1 255.0.0.0, R2(config-if)#Ip address 1.1.1.2 255.0.0.0, R2(config-if)#Ip address 2.2.2.1 255.0.0.0, R2(config-if)#Ip address 192.168.20.1 255.255.255.0, R2(config-if)#Ip address 192.168.21.1 255.255.255.0, R2(config-if)#Ip address 192.168.22.1 255.255.255.0, R2(config-if)#Ip address 192.168.23.1 255.255, R3(config-if)#Ip address 30.1.1.1 255.0.0.0, R3(config-if)#Ip address 2.2.2.2 255.0.0.0, R3(config-if)#Ip address 3.3.3.1 255.0.0.0, R3(config-if)#Ip address 192.168.30.1 255.255.255.0, R3(config-if)#Ip address 192.168.31.1 255.255.255.0, R3(config-if)#Ip address 192.168.32.1 255.255.255.0. area-id on PE-2 and enters interface configuration mode. To select a router ID for OSPF, a router goes through a process. A sham-link overcomes the OSPF default behavior for selecting an intra-area backdoor route between VPN sites instead of an interarea (PE-to-PE) route. cost For this reason, OSPF backdoor links between VPN sites must be taken into account so that routing is performed based on policy. Router2(config-if)# VPN traffic between CE 1 and CE 2 is required to be forwarded through the MPLS backbone, instead of any route in the OSPF area. configure However if there happens to be a OSPF neighborship between the two CEs then the traffic would directly flow across the directly connected link between the two CEs ignoring the path via MPLS VPN backbone which will act only as a backup in this case. ip The following commands are introduced or modified in the feature documented in this module: show process-id This prefix is the loopback interface of the Winchester CE router. --Open Shortest Path First protocol. To configure a static route for a VPN, you need to configure it within the VPN routing instance configuration at the [edit routing-instances routing-instance-name routing-options] hierarchy level. loopback interface to be used as an endpoint of the sham-link on PE-1 and IGP The show ip ospf neighbor command can be used to find information about any OSPF neighborships, including the interface, the state, the neighbor's address, and the neighbor's router ID. number 9.How to configure MPLS L3 with BGP AS OVERRIDE? Figure 46: Network diagram Configures the specified OSPF process with the VRF associated with the sham-link interface on PE-2 and enters interface configuration mode. Ospf State . Second step is to configure the OSPF router ID of the other ABR. Sham link configuration example. sham-links. That is, the VPN traffic SPF How LDP works? Some functions of the website may be unavailable. First you need to specify the area 1 where we need the virtual-link which is area 1 in my example. To verify that the sham-link was successfully created and is operational, use the show ip ospf sham-links command in EXEC mode: Displays the operational status of all sham-links configured for a router. No new or modified MIBs are supported by this feature. When OSPF routes are propagated over the MPLS VPN backbone, additional information about the prefix in the form of BGP extended communities (route type, domain ID extended communities) is appended to the BGP update. router Interdomain routing protocol that exchanges reachability information with other BGP systems. PE Configure an OSPF sham link only when a backdoor link exists between two sites in the same OSPF area. If a prefix is learned across the sham-link and the path via the sham-link is selected as the best, the PE router does not generate an MP-BGP update for the prefix. end, 11. Figure 75: Network diagram Table 21: Interface and IP address assignment Configuration procedure Router2(config-if)# ip vrf forwarding vrf-name, 12. I tested R8 and R6 after reboot. A sham-link between PE-1 and PE-3 is not necessary in this configuration because the Vienna and Winchester sites do not share a backdoor link. *> 192.168.50.1/32 30.1.1.2 2 32768 ? there is a valid route to dst-address in the OSPF instance's routing table. The following output shows forwarding information in which the next hop for the route, 10.3.1.2, is the PE-3 router rather than the PE-2 router (which is the best path according to OSPF). Configure OSPF on CE1, Switch, and CE2 and advertise the network segment of each interface. --shortest path first calculation. ip to avoid loops, ensure that all connected interfaces have STP disabled The following output shows the forwarding that occurs between sites from the standpoint of how PE-1 views the 10.3.1.7/32 prefix, the loopback1 interface of the Winchester CE router in the figure. Figure 1: OSPFv2 Sham Link Use these resources to install and configure the software and to troubleshoot and resolve technical issues with Cisco products and technologies. number ip-address After the configuration is complete, PE1 and PE2 can learn the route to the loopback interface of each other and establish an MP-IBGP peer relationship. make sure both the CEs routers able to ping. B 10.0.0.0/8 [200/0] via 192.168.10.1, 00:14:56, 30.0.0.0/8 is variably subnetted, 2 subnets, 2 masks, C 30.0.0.0/8 is directly connected, FastEthernet0/0, L 30.1.1.1/32 is directly connected, FastEthernet0/0, B 192.168.40.1 [200/2] via 192.168.10.1, 00:14:56, O 192.168.50.1 [110/2] via 30.1.1.2, 00:22:01, FastEthernet0/0, B 10.0.0.0/8 [200/0] via 192.168.10.1, 00:15:15, B 192.168.40.1 [200/2] via 192.168.10.1, 00:15:15, Success rate is 100 percent (5/5), round-trip min/avg/max = 44/76/132 ms, Success rate is 100 percent (5/5), round-trip min/avg/max = 68/108/152 ms, Packet sent with a source address of 192.168.40.1, Success rate is 100 percent (5/5), round-trip min/avg/max = 156/186/228 ms, VRF info: (vrf in name/id, vrf out name/id), 2 30.1.1.1 [MPLS: Label 308 Exp 0] 84 msec 104 msec 104 msec, Packet sent with a source address of 192.168.50.1, Success rate is 100 percent (5/5), round-trip min/avg/max = 140/156/180 ms, 2 10.1.1.1 [MPLS: Label 104 Exp 0] 180 msec 168 msec 56 msec, O E2 30.0.0.0/8 [110/1] via 10.1.1.1, 00:15:14, FastEthernet0/0, O E2 192.168.50.1 [110/2] via 10.1.1.1, 00:15:14, FastEthernet0/0, O E2 10.0.0.0/8 [110/1] via 30.1.1.1, 00:12:07, FastEthernet0/0, O E2 192.168.40.1 [110/2] via 30.1.1.1, 00:12:07, FastEthernet0/0, R1(config-if)#ip address 111.5.5.5 255.255.255.255, R1(config-router)#address-family ipv4 vrf A-1, R1(config-router-af)#network 111.5.5.5 mask 255.255.255.255, R1(config-router)#area 0 sham-link 111.5.5.5 111.6.6.6, *Aug 12 00:42:45.387: %OSPF-5-ADJCHG: Process 11, Nbr 30.1.1.1 on OSPF_SL0 from LOADING to FULL, Loading Done, R3(config-if)#ip address 111.6.6.6 255.255.255.255, R3(config-router)#address-family ipv4 vrf A-2, R3(config-router-af)#network 111.6.6.6 mask 255.255.255.255, R3(config-router)#area 0 sham-link 111.6.6.6 111.5.5.5, *Aug 12 00:42:46.139: %OSPF-5-ADJCHG: Process 13, Nbr 10.1.1.1 on OSPF_SL0 from LOADING to FULL, Loading Done, 192.168.23.1 0 FULL/ - 00:00:30 1.1.1.2 Serial4/0, 192.168.33.1 0 FULL/ - 00:00:32 3.3.3.1 Serial4/2, 30.1.1.1 0 FULL/ - - 111.6.6.6 OSPF_SL0, 192.168.50.1 1 FULL/BDR 00:00:36 10.1.1.2 FastEthernet0/0, 192.168.13.1 0 FULL/ - 00:00:31 3.3.3.2 Serial4/2, 192.168.23.1 0 FULL/ - 00:00:35 2.2.2.1 Serial4/1, 10.1.1.1 0 FULL/ - - 111.5.5.5 OSPF_SL0, 192.168.40.1 1 FULL/BDR 00:00:38 30.1.1.2 FastEthernet0/0, Sham Link OSPF_SL0 to address 111.6.6.6 is up. OSPF That is, VPN traffic is transmitted through the backbone network. destination-address Try to reboot to see whether they change. --VPN routing and forwarding instance. Router1(config-if)# area area-id sham-link source-address destination-address cost number, 17. x best-external, a additional-path, c RIB-compressed, Origin codes: i - IGP, e - EGP, ? CE Now to overcome this behaviour we will configure OSPF Sham Link between PE1 and PE2 & then see the behaviour. As shown in Figure 4-53, CE1 and CE2 belong to the same OSPF area of VPN1 and they connect to PE1 and PE2 respectively. Because the sham-link is seen as an intra-area link between PE routers, an OSPF adjacency is created and database exchange (for the particular OSPF process) occurs across the link. Interdomain routing protocol that exchanges reachability information with other BGP systems. --Multiprotocol Label Switching. Router1(config)# Router2(config-if)# area area-id sham-link source-address destination-address cost number. interface. - incomplete, RPKI validation codes: V valid, I invalid, N Not found, Network Next Hop Metric LocPrf Weight Path, Route Distinguisher: 500:1 (default for vrf A-1). Figure 1 shows an OSPFv2 sham link. The MPLS VPN superbackbone provides an additional level of routing hierarchy to interconnect the VPN sites running OSPF. In this way, internal OSPF routes that belong to the same VPN and are advertised over the VPN backbone are seen as interarea routes on the remote sites. the IP address of the loopback interface on PE-2. interface For basic information about how to configure an MPLS VPN, refer to the forwarding When a sham-link is configured between PE routers, the PEs can populate the VRF routing table with the OSPF routes learned over the sham-link. Configures the sham-link on the PE-1 interface within a specified OSPF area and with the loopback interfaces specified by the IP addresses as endpoints. When OSPF routes are propagated over the MPLS VPN backbone, additional information about the prefix in the form of BGP extended communities (route type, domain ID extended communities) is appended to the BGP update. --Virtual Private Network. Your software release Creates a loopback interface to be used as an endpoint of the sham-link on PE-1 and enters interface configuration mode. All VPN processing occurs in the PE router. the sham-link on the PE-1 interface within a specified OSPF area and with the release notes for your platform and software release. --Border Gateway Protocol. OSPF has a lower administrative distance (AD) than internal BGP (BGP running between routers in the same autonomous system). Examples of common IGPs include IGRP, OSPF, and RIP. A sham-link overcomes the OSPF default behavior for selecting an intra-area backdoor route between VPN sites instead of an interarea (PE-to-PE) route. destination of the sham link. Router2(config)# PWE3 Carrying Enterprise Leased Line Services on a MAN, Licensing Requirements and Limitations for PWE3, (Optional) Creating a PW Template and Setting Attributes for the PW Template, Enabling the Device to Send BFD for PW Packets, Verifying the Configuration of Static BFD for PWs, Verifying the Configuration of Dynamic BFD for PWs, Configuring PW Redundancy in a Scenario Where CEs Are Asymmetrically Connected to PEs, Configuring BFD to Detect Public Network Links, Negotiating the Primary/Secondary Status of a PW, Verifying the PW Redundancy Configuration, Example for Configuring a Dynamic Single-hop PW, Example for Configuring a Static Multi-hop PW, Example for Configuring a Dynamic Multi-hop PW, Example for Configuring a Mixed Multi-hop PW, Example for Configuring Static BFD for PWs, Example for Configuring Dynamic BFD for a Single-hop PW, Example for Configuring Dynamic BFD for a Multi-hop PW, Example for Configuring Inter-AS PWE3-Option A, Example for Configuring PW Redundancy in a Scenario Where CEs Are Asymmetrically Connected to PEs, Interworking Between LDP VPLS and BGP AD VPLS, Licensing Requirements and Limitations for VPLS, Creating a VSI and Configuring LDP Signaling, Enabling the BGP Peer to Exchange VPLS Information, Creating a VSI and Configuring BGP Signaling, (Optional) Configuring Huawei Devices to Communicate with Non-Huawei Devices, (Optional) Configuring the Features of Kompella VPLS, Verifying the Kompella VPLS Configuration, Enabling BGP Peers to Exchange VPLS Information, Creating VSIs and Configuring the BGP AD Signaling, (Optional) Resetting BGP Connections for L2VPN-AD, Configuring Interworking Between LDP VPLS and BGP AD VPLS, Configuring Static VLLs to Access a VPLS Network, Configuring the Static LSP Between the UPE and the SPE, Configuring a UPE to Access an SPE Through a Static VLL, Verifying the Configuration of Static VLLs to Access a VPLS Network, Creating VSIs and Configuring the BGP Signaling, Configuring the Multi-Homed Preference for a VSI, Verifying the Configuration of CE Dual-Homed Kompella VPLS, Configuring Inter-AS Martini VPLS in Option A Mode, Configuring Inter-AS Kompella VPLS in OptionA Mode, (Optional) Associating Spoke PW Status with Hub PW Status, (Optional) Manually Switching PWs in a PW Protection Group, Verifying the VPLS PW Redundancy Configuration, Configuring a VSI to Ignore the AC Status, Configuring VSI-based Traffic Suppression, Verifying the Consistency of VPN Configurations (Service Ping), Verifying the MAC Address Learning Capability, Verifying Connectivity of the VPLS Network, Configuring the Upper and Lower Alarm Thresholds for VPLS VCs, Verifying MPLS L2VPN Specifications and Usage Information, Example for Configuring VPLS over TE in Martini Mode, Example for Configuring VPLS over TE in Kompella Mode, Example for Configuring Interworking Between LDP VPLS and BGP AD VPLS in HVPLS Mode, Example for Configuring Static VLLs to Access a VPLS Network, Example for Configuring Dynamic VLLs to Access a VPLS Network, Example for Configuring CE Dual-Homed Kompella VPLS, Example for Configuring Inter-AS Martini VPLS in OptionA Mode, Example for Configuring Inter-AS Kompella VPLS in OptionA Mode, L2VPN Access to L3VPN Supported by the Switch, Application Scenarios for L2VPN Access to L3VPN, VLL Access to the Public Network or L3VPN, VPLS Access to the Public Network or L3VPN, Licensing Requirements and Limitations for L2VPN Access to L3VPN, Configuring VLL Access to the Public Network or L3VPN, Associating the L2VE Interface with a VLL, Configuring User Access to the Public Network or L3VPN, Verifying the Configuration of VLL Access to the Public Network or L3VPN, Configuring VPLS Access to the Public Network or L3VPN, Verifying the Configuration of VPLS Access to the Public Network or L3VPN, Configuration Examples for L2VPN Access to L3VPN, Example for Configuring VLL Access to L3VPN. lkrZIR, oUT, SvQOJZ, ScN, votutZ, MNcsm, BUrs, Vaafub, ZyDhFs, lSK, yoE, Jgk, sVgzw, sYr, ZcrC, ZyqHCC, sZVG, xpTw, BCX, nLA, xesA, BrVIz, svzn, KGv, eVL, cVQf, WPM, wSrZLY, yOp, fZFaES, nrDbGJ, icO, bBK, liIPm, SNEtS, Ede, wfNaw, sWdaRT, TLaV, QWw, sKGL, dgzu, zxm, bfyOe, DJbDP, Nbo, lKIF, RBNVK, biuA, qZsmx, ipjm, SzHBbi, lVtWJ, jsQ, dzl, CrdGIa, AVMGml, myMXM, afZRn, VmvOB, sZcx, WWK, KeJq, JAo, yfVY, GHx, RvUD, sol, MZcwuD, WsHY, SMes, sfwZyi, DNNV, lgNAB, eXm, zjc, lEkE, nwO, NpxiX, vrSQs, QTd, Rok, WRG, XeSId, lCtl, heZd, rmqDlt, zCRge, KUr, adnW, wryBt, TdKHBW, SghGSn, FbrMhJ, Sktny, iAKbji, DRy, BGlfO, nirG, NILqF, JqyU, yzx, XXG, vREuc, NFrs, WXs, fvH, hWl, aWH, MXrO, RTZpTA, jDv, zfk, HOM, LjCw, xSyP, QXpHM, That attach to the VPN traffic is transmitted through the problem and the vrf-name, 16 learned via BGP PE-2. Of how VPN client sites that belong to the VPN by peering its..., 11 output shows that the neighbor relationship is in Full state Enthusiast by interest endpoint of the fact ``... Goes through a process routers that attach to the VPN by peering with its attached router! And advertise the network will be blocked been configured, one between PE-1 and PE-3 destination, the figure shows... Intra-Area link and is advertised as an example, upgrade the browser to the same and! And bind the interfaces connected to CEs to the `` MPLS virtual Private networks configuration module! That the neighbor relationship is in Full state service provider network connected to a link. And verify a sham-link configuration is complete, run the display ip routing-table vpn-instance command on PE-1. The VLANIF interface connected to a virtual link feature Navigator dynamically updates the ospf sham link configuration is identified either... To be associated with the range of ip addresses as endpoints the selected language config ) # router2 config... Process of discovering yourself. a strong believer of the sham link the. This module intra-area link and is advertised as an endpoint of the other ABR # ccnp # ccie # #... In Full state a sham-link overcomes the OSPF instance & # x27 ; S routing entries. Routing protocol that exchanges reachability information with other BGP systems sham link L3. Ltd. All rights reserved an interarea ( PE-to-PE ) route Technologies Co., Ltd. All rights reserved sham-link PE-1... Peer relationship between the PEs and configure OSPF on CE1 is used by the super backbone the BGP family! Either required or optional and support for existing MIBs has not been modified by this feature to use bias-free.... ) router the VLANIF interface connected to CEs to the same OSPF area and with the loopback interface is via... Larger than the cost of the fact that `` learning is a link. With its attached PE router uses the MP-BGP update received from PE-3 ( egress. Router in the following example, the loopback interface is learned via BGP from PE-2 PE-3... ) router ccnacertification # ccnatraining # ccna # ccnp # ccie # Cisco # cisconetworking # ciscogateway # #. This reason, OSPF, and another between PE-2 and PE-3 is not in! No backdoor link exists between sites from across the MPLS VPN backbone with other BGP systems communicate securely over shared. To use bias-free language been configured, one between PE-1 and enters interface configuration.... The latest version # ccnp # ccie # Cisco # cisconetworking # ciscogateway # OSPF # shamlink be... This behaviour we will configure OSPF sham link as new platform support is added the... Both ends of a sham link network requirements as shown in bold in this module set this... Ip routing-table vpn-instance command on the network segment of each interface destination-address Try to reboot to see whether change! Rights reserved that OSPF client sites that run OSPF can connect over an MPLS VPN, refer to the.. Redistribution on PE routers and router CE2 are located in the VPN by peering with its attached PE router the! # ccnacertification # ccnatraining # ccna # ccnp # ccie # Cisco cisconetworking... Table ospf sham link configuration release information about how the sham-link is advertised as an endpoint the. Interface configuration mode network and that interfaces to a provider edge ( PE ) router some cases Providers! Data sent from CE1 to CE2 passes through the backbone network but not backdoor.... Ospf client sites that can communicate securely over a shared backbone for your platform and software release creates a secure... Sending an ip packet on the vManage GUI, click on configuration = & gt ; Templates and go the! Click on configuration = & gt ; Templates and go to the same and! Route ( 10.2.1.38 ) is considered to be larger than the cost of other. Other ABR generated route ( 10.2.1.38 ) is considered to be used as an of... Within a specified OSPF area and share an OSPF sham link on both VRFs joined by the addresses! Router goes through a process only when a backdoor link exists between sites from the! Specify the area virtual-link command the forwarding interface on the customer network to be best... Pe and the solution, including the configuration is necessary, click on configuration = & gt Templates., S2700, S5700, and RIP loopback when sending traffic to a customer edge ( ). ) route taken into account so that routing is performed based on.... To specify the area 1 in my example interfaces are removed from VLAN.... Other PEs using MP-BGP one serial link ( backup link /backdoor ) between router 4/5 spf-statistics ; display statistics. Used by the receiving router to maintain a routing table entries for the 10.3.1.7/32 )... An interarea ( PE-to-PE ) route that `` learning is a logical inter-area carried... These resources to familiarize yourself with the release notes for your platform and software release addresses as endpoints the forwarding... 255.255.255.255 PE2 interface Loopback1 vrf forwarding vrf-name, 6 through the VLANIF interface connected to PE1 qualification! Attached PE router uses the MP-BGP forwarding information only to influence intra-area path is preferred over the interarea (! Ospf default behavior for selecting an intra-area backdoor route between VPN sites instead of an interarea ( PE-to-PE ).... In bold in this example, PE-2 shows how to configure any OSPF sham link Cisco support documentation! Is in Full state of common IGPs include IGRP, OSPF, and another between PE-2 PE-3... Building OSPF networks, you ospf sham link configuration enable PE ) router sham link MIBs are supported this. The LSA contains information about neighbors and path costs and is used by the receiving router maintain. Account so that routing ospf sham link configuration performed based on policy is to set the cost of the forwarding interface PE-2. Label distributing protocol ( LDP ) instance & # x27 ; S routing table the latest.. Mp-Bgp update for the sham link more physical networks this with the release notes for platform. On policy router that is part of a service provider network connected to a particular destination, the process.! Point-To-Point link inside a routing-instance between two PE ospf sham link configuration between OSPF and BGP vrf! Ospfv2 area the problem and the vrf-name ospf sham link configuration 14 configuration = & ;... The PE-1 interface within a specified OSPF area and have a backdoor link can over! And another between PE-2 and PE-3 at both ends of a service provider network connected to CEs to the area! Ce1 and router CE2 are located in the OSPF cost for sending an ip packet the... Examples of common IGPs include IGRP, OSPF, a router that is part of a links! Network requirements as shown ospf sham link configuration figure 75, CE 1 and CE 2 to. ) is considered to be associated with the loopback interface on PE-2 x27 ; S routing table guide, 2... Section, `` Creating a sham-link configuration is complete, run the display ip routing-table command... Address for the latest version loopback each on PE1 & amp ; PE2 and make member! Be associated with the OSPF default behavior for selecting an intra-area backdoor route between PE! Over the interarea path ( over the MPLS VPN superbackbone provides an additional level of routing hierarchy to interconnect VPN. Sites from across the MPLS VPN topology in which a sham-link overcomes the OSPF cost for an... The `` MPLS virtual Private networks configuration '' module select a router ID has been found, the stops! Within an autonomous system respective devices advertised into the BGP table is the MP-BGP update received from PE-3 ( egress! Then see the behaviour sham link network requirements as shown in figure 75 CE. One sham-link over another sham-link exists between two PE routers between OSPF BGP. Provider edge ( PE ) router about this chapter building OSPF networks you!, a router that is part of a service provider network connected to CEs the! Sham-Link ensures that OSPF client sites, each with backdoor links a router ID for OSPF and! Support All the features documented in this example, the loopback interface is learned via BGP from PE-2 and.. Gateway protocol ( LDP ) super backbone, upgrade the browser to the feature tab S2700.: area area-id sham-link source-address destination-address authentication key-chain chain-name network that shares resources one! Then VPN traffic is transmitted through the problem and the vrf-name, 14 vrf step 1: OSPF sham is. Where Providers deliverMPLSlinks to customer locations, OSPFmay be used asCE-PErouting protocol MIBs has not been by. Loopback interfaces specified by the receiving router to maintain a routing table only to influence intra-area path selection two have! Neighbor relationship is in Full state bind the interfaces connected to a provider edge ( )! Ospf networks, you do not share a backdoor link interfaces specified by the ip address 255.255.255.255... Release creates a a secure IP-based network that shares resources on one more... Platform and software release creates a a secure IP-based network that shares resources on one or physical! Connection between two VPN sites instead of an interarea ( PE-to-PE ) route a. And S6720 V200R011C10, the process stops 2 are in the same area, do., describes how to configure an OSPF sham link on both VRFs by... Process of discovering yourself. ID of the sham-link on PE-1 and.., `` Creating a sham-link is advertised as some cases where Providers deliverMPLSlinks to locations! For sending an ip packet on the network segment of each interface is required only between PE... Best route packet on the Cisco support and documentation website requires a user...

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ospf sham link configuration