Cisco 1400 series - Manuals

Page 2 - Using a Sham-Link to Correct OSPF Backdoor Routing

OSPF Sham-Link Support for MPLS VPN Feature Overview 2 Cisco IOS Release 12.2(8)T Figure 1 OSPF Connectivity Between VPN Client Sites and an MPLS VPN Backbone When OSPF is used to connect PE and CE routers, all routing information learned from a VPN site is placedin the VPN routing and forwarding (V...

Page 5 - Sham-Link Configuration Example

OSPF Sham-Link Support for MPLS VPN Feature Overview 5 Cisco IOS Release 12.2(8)T Figure 3 Using a Sham-Link Between PE Routers to Connect OSPF Client Sites Because the sham-link is seen as an intra-area link between PE routers, an OSPF adjacency is created anddatabase exchange (for the particular O...

Page 7 - Benefits

OSPF Sham-Link Support for MPLS VPN Feature Overview 7 Cisco IOS Release 12.2(8)T PE-1# show ip cef vrf ospf 10.3.1.7 10.3.1.7/32, version 73, epoch 0, cached adjacency to POS3/0/0 0 packets, 0 bytes tag information set local tag: VPN-route-head fast tag rewrite with PO3/0/0, point2point, tags impos...

Page 8 - Restrictions; Supported Platforms

OSPF Sham-Link Support for MPLS VPN Supported Platforms 8 Cisco IOS Release 12.2(8)T Restrictions When OSPF is used as a protocol between PE and CE routers, the OSPF metric is preserved when routesare advertised over the VPN backbone. The metric is used on the remote PE routers to select the correct...

Page 10 - Prerequisites

OSPF Sham-Link Support for MPLS VPN Supported Standards, MIBs, and RFCs 10 Cisco IOS Release 12.2(8)T Supported Standards, MIBs, and RFCs Standards No new or modified standards are supported by this feature. MIBs No new or modified MIBs are supported by this feature. To obtain lists of supported MIB...

Page 11 - Command

OSPF Sham-Link Support for MPLS VPN Configuration Tasks 11 Cisco IOS Release 12.2(8)T To create a sham-link, use the following commands starting in EXEC mode: Verifying Sham-Link Creation To verify that the sham-link was successfully created and is operational, use the show ip ospfsham-links command...

Page 12 - Monitoring and Maintaining a Sham-Link; To monitor a sham-link, use the following show commands in EXEC mode:; Configuration Examples; show ip ospf sham-links

OSPF Sham-Link Support for MPLS VPN Monitoring and Maintaining a Sham-Link 12 Cisco IOS Release 12.2(8)T Timer intervals configured, Hello 10, Dead 40, Wait 40, Hello due in 00:00:04 Adjacency State FULL (Hello suppressed) Index 2/2, retransmission queue length 4, number of retransmission 0 First 0x...

Page 14 - Examples

OSPF Sham-Link Support for MPLS VPN area sham-link cost 14 Cisco IOS Release 12.2(8)T Examples The following example shows how to configure a sham-link between two PE routers in an MPLS VPNbackbone by using the area sham-link cost command on each router: Router1(config)# interface loopback 55 Router...

Page 16 - Glossary; OSPF—Open Shortest Path First protocol.

OSPF Sham-Link Support for MPLS VPN Glossary 16 Cisco IOS Release 12.2(8)T Glossary BGP—Border Gateway Protocol. Interdomain routing protocol that exchanges reachability informationwith other BGP systems. It is defined in RFC 1163. CE router—customer edge router. A router that is part of a customer ...