Instruction/ maintenance manual of the product 1400 series Cisco Systems
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1 Cisco IOS Release 12.2(8)T OSPF Sham-Link Support for MPLS VPN Feature History This document describes how to conf igure and use a sham-link to connect V irtual Priv ate 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 conf iguration.
OSPF Sham-Link Support for MPLS VPN Feature Overview 2 Cisco IOS Release 12.2(8)T Figur e 1 OSPF Connectivity Between VPN Client Sit es and an MPLS VPN Backbone When OSPF is used to connect PE and CE .
OSPF Sham-Link Support for MPLS VPN Feature Overview 3 Cisco IOS Release 12.2(8)T Figur e 2 Backdoor P aths Between OSPF Client Sites For example, Figure 2 shows three client sites, each with backdoor links.
OSPF Sham-Link Support for MPLS VPN Feature Overview 4 Cisco IOS Release 12.2(8)T 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.
OSPF Sham-Link Support for MPLS VPN Feature Overview 5 Cisco IOS Release 12.2(8)T Figur e 3 Using a Sham-Link Between PE Rout ers to Connect OSPF Client Sit es 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.
OSPF Sham-Link Support for MPLS VPN Feature Overview 6 Cisco IOS Release 12.2(8)T Figur e 4 Sham-Link Example 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 Figure 4 .
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 imposed: {42 38} via 10.
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 routes are advertised o ver the VPN backbone. The metric is used on the remote PE routers to select the correct route.
OSPF Sham-Link Support for MPLS VPN Supported Platforms 9 Cisco IOS Release 12.2(8)T • Cisco 1721 • Cisco 1750 • Cisco 1751 • Cisco 2420 • Cisco 2600 • Cisco 2691 • Cisco 3620 • Cisco .
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 modif ied standards are supported by this feature. MIBs No new or modif ied MIBs are supported by this feature.
OSPF Sham-Link Support for MPLS VPN Configuration Tasks 11 Cisco IOS Release 12.2(8)T T o create a sham-link, use the follo wing commands starting in EXEC mode: Verifying Sham-Link Creation T o verify.
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 F.
OSPF Sham-Link Support for MPLS VPN area sham-link cost 13 Cisco IOS Release 12.2(8)T area sham-link cost T o conf igure a sham-link interface on a provider edge (PE) router in a Multiprotocol Label Switching (MPLS) V irtual Priv ate Network (VPN) backbone, use the ar ea sham-link cost command in global conf iguration mode.
OSPF Sham-Link Support for MPLS VPN area sham-link cost 14 Cisco IOS Release 12.2(8)T Examples The following e xample sho ws ho w to conf igure a sham-link between tw o PE routers in an MPLS VPN backb.
OSPF Sham-Link Support for MPLS VPN show ip ospf sham-links 15 Cisco IOS Release 12.2(8)T show ip ospf sham-links T o display information about all sham-links conf igured for a provider edge (PE) router in the V irtual Priv ate Netw ork (VPN) backbone, use the show ip ospf sham-links command in EXEC mode.
OSPF Sham-Link Support for MPLS VPN Glossary 16 Cisco IOS Release 12.2(8)T Glossary BGP —Border Gate way Protocol. Interdomain routing protocol that exchanges reachability information with other BGP systems. It is def ined in RFC 1163. CE router —customer edge router .
An important point after buying a device Cisco Systems 1400 series (or even before the purchase) is to read its user manual. We should do this for several simple reasons:
If you have not bought Cisco Systems 1400 series yet, this is a good time to familiarize yourself with the basic data on the product. First of all view first pages of the manual, you can find above. You should find there the most important technical data Cisco Systems 1400 series - thus you can check whether the hardware meets your expectations. When delving into next pages of the user manual, Cisco Systems 1400 series you will learn all the available features of the product, as well as information on its operation. The information that you get Cisco Systems 1400 series will certainly help you make a decision on the purchase.
If you already are a holder of Cisco Systems 1400 series, but have not read the manual yet, you should do it for the reasons described above. You will learn then if you properly used the available features, and whether you have not made any mistakes, which can shorten the lifetime Cisco Systems 1400 series.
However, one of the most important roles played by the user manual is to help in solving problems with Cisco Systems 1400 series. Almost always you will find there Troubleshooting, which are the most frequently occurring failures and malfunctions of the device Cisco Systems 1400 series along with tips on how to solve them. Even if you fail to solve the problem, the manual will show you a further procedure – contact to the customer service center or the nearest service center
