hit counter script
Cisco 1400 series Specification Sheet
  1. Manuals
  2. Brands
  3. Cisco Manuals
  4. Network Router
  5. Aironet 1400 Series
  6. Specification sheet
Cisco 1400 series Specification Sheet

Cisco 1400 series Specification Sheet

Cisco router connections specification sheet
Hide thumbs Also See for 1400 series:
Table of Contents

Advertisement

Quick Links

See also: Manual
OSPF Sham-Link Support for MPLS VPN
Feature History
Release
12.2(8)T
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.
This document includes the following sections:
Feature Overview, page 1
•
Supported Platforms, page 8
•
•
Supported Standards, MIBs, and RFCs, page 10
Prerequisites, page 10
•
•
Configuration Tasks, page 10
Configuration Examples, page 12
•
Command Reference, page 12
•
•
Glossary, page 16

Feature Overview

Using OSPF in PE-CE Router Connections
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. 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
between their sites using OSPF (during migration or on a permanent basis) over an MPLS VPN backbone.
Figure 1
backbone.
Modification
This feature was introduced.
shows an example of how VPN client sites that run OSPF can connect over an MPLS VPN
Cisco IOS Release 12.2(8)T
1

Advertisement

Table of Contents
loading

Related Manuals for Cisco 1400 series

Summary of Contents for Cisco 1400 series

  • Page 1: Feature Overview

    OSPF Sham-Link Support for MPLS VPN Feature History Release 12.2(8)T 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.
  • Page 2 OSPF Sham-Link Support for MPLS VPN Feature Overview Figure 1 OSPF Connectivity Between VPN Client Sites and an MPLS VPN Backbone Area 1 Area 1 MPLS VPN Area 2 Superbackbone Area 0 Area 0 Area 3 When OSPF is used to connect PE and CE routers, all routing information learned from a VPN site is placed in the VPN routing and forwarding (VRF) instance associated with the incoming interface.
  • Page 3 OSPF Sham-Link Support for MPLS VPN Figure 2 Backdoor Paths Between OSPF Client Sites 10.3.1.6 Area 1 For example, Figure 2 the same Area 1 configuration, all routing between the three sites follows the intraarea path across the backdoor links, rather than over the MPLS VPN backbone. The following example shows BGP routing table entries for the prefix 10.3.1.7/32 in the PE-1 router in Figure 2.
  • Page 4 Feature Overview PE-1# show ip route vrf ospf 10.3.1.7 Routing entry for 10.3.1.7/32 Known via "ospf 100", distance 110, metric 86, type intra area Redistributing via bgp 215 Advertised by bgp 215 Last update from 10.2.1.38 on Serial0/0/0, 00:00:17 ago Routing Descriptor Blocks: * 10.2.1.38, from 10.3.1.7, 00:00:17 ago, via Serial0/0/0 Route metric is 86, traffic share count is 1...
  • Page 5 OSPF Sham-Link Support for MPLS VPN Figure 3 Using a Sham-Link Between PE Routers to Connect OSPF Client Sites PE-1 10.3.1.6 Area 1 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.
  • Page 6 Feature Overview Figure 4 Sham-Link Example Area 1 The following example 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 PE-1# show ip bgp vpnv4 all 10.3.1.7 BGP routing table entry for 100:251:10.3.1.7/32, version 124 Paths: (1 available, best #1) Local...
  • Page 7 OSPF Sham-Link Support for MPLS VPN 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 imposed: {42 38} via 10.3.1.2, 0 dependencies, recursive next hop 10.1.1.17, POS3/0/0 via 10.3.1.2/32 valid cached adjacency...

  • Page 8: Related Documents

    • RFC 2283, Multiprotocol Extensions for BGP-4 • RFC 2328, Open Shortest Path First, Version 2 • RFC 2547, BGP/MPLS VPNs • Supported Platforms • Cisco 1400 series • Cisco 1600 • Cisco 1600R • Cisco 1710 • Cisco 1720 Cisco IOS Release 12.2(8)T...
  • Page 9 OSPF Sham-Link Support for MPLS VPN Cisco 1721 • Cisco 1750 • Cisco 1751 • Cisco 2420 • Cisco 2600 • Cisco 2691 • Cisco 3620 • • Cisco 3631 • Cisco 3640 • Cisco 3660 • Cico 3725 • Cisco 3745 Cisco 7100 •...

  • Page 10: Supported Standards, Mibs, And Rfcs

    Supported Standards, MIBs, and RFCs 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 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 RFCs...
  • Page 11 OSPF Sham-Link Support for MPLS VPN To create a sham-link, use the following commands starting in EXEC mode: Command Step 1 Router1# configure terminal Step 2 Router1(config)# interface loopback interface-number Step 3 Router1(config-if)# ip vrf forwarding vrf-name Step 4 Router1(config-if)# ip address ip-address mask Step 5 Router1(config-if)# end...

  • Page 12: Configuration Examples

    Monitoring and Maintaining a Sham-Link 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 0x63311F3C(205)/0x63311FE4(59) Next 0x63311F3C(205)/0x63311FE4(59) Last retransmission scan length is 0, maximum is 0 Last retransmission scan time is 0 msec, maximum is 0 msec Link State retransmission due in 360 msec Monitoring and Maintaining a Sham-Link...
  • Page 13 OSPF Sham-Link Support for MPLS VPN area sham-link cost To configure a sham-link interface on a provider edge (PE) router in a Multiprotocol Label Switching (MPLS) Virtual Private Network (VPN) backbone, use the area sham-link cost command in global configuration mode. To remove the sham-link, use the no form of this command. area area-id sham-link source-address destination-address cost number no area area-id sham-link source-address destination-address cost number Syntax Description...
  • Page 14 OSPF Sham-Link Support for MPLS VPN area sham-link cost Examples The following example shows how to configure a sham-link between two PE routers in an MPLS VPN backbone by using the area sham-link cost command on each router: Router1(config)# interface loopback 55 Router1(config-if)# ip vrf forwarding v1 Router1(config-if)# ip address 10.0.0.1 255.255.255.255 Router1(config)# router ospf 2 vrf v1...
  • Page 15 OSPF Sham-Link Support for MPLS VPN show ip ospf sham-links To display information about all sham-links configured for a provider edge (PE) router in the Virtual Private Network (VPN) backbone, use the show ip ospf sham-links command in EXEC mode. show ip ospf sham-links Syntax Description This command has no arguments or keywords.
  • Page 16 OSPF Sham-Link Support for MPLS VPN Glossary Glossary BGP—Border Gateway Protocol. Interdomain routing protocol that exchanges reachability information with other BGP systems. It is defined in RFC 1163. CE router—customer edge router. A router that is part of a customer network and that interfaces to a provider edge (PE) router.

This manual is also suitable for:

16001600r

Table of Contents

Save PDF