Cisco IOS Software Releases 12.0 ST

Table Of Contents

MPLS VPN Inter-AS—IPv4 BGP Label Distribution

Feature Overview

BGP Overview

Types of BGP Messages

How BGP Sends MPLS Labels with Routes

Using Route Maps to Filter Routes

Benefits

Restrictions

Related Features and Technologies

Related Documents

Supported Platforms

Supported Standards, MIBs, and RFCs

Prerequisites

Configuration Tasks

Configuring the ASBRs to Exchange IPv4 Routes and MPLS Labels

Configuring the Route Reflectors to Exchange VPNv4 Routes

Configuring the Route Reflectors to Reflect Remote Routes in Its AS

Creating Route Maps

Configuring a Route Map for Arriving Routes

Configuring a Route Map for Departing Routes

Applying the Route Maps to the ASBRs

Verifying the Configuration

Verifying the Route Reflector Configuration

Verifying That Routers Exchange Network Reachability Information

Verifying the ASBR Configuration

Configuration Examples

Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels

Route Reflector 1 Configuration

ASBR1 Configuration

Route Reflector 2 Configuration

ASBR2 Configuration

Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels Over a Non MPLS VPN Service Provider

Route Reflector 1 Configuration

ASBR1 Configuration

Route Reflector 2 Configuration

ASBR2 Configuration

ASBR3 Configuration

Route Reflector 3 Configuration

ASBR4 Configuration

Command Reference

debug ip bgp

match mpls-label

neighbor send-label

set mpls-label

show ip bgp

show ip bgp labels

show ip bgp neighbors

show ip bgp vpnv4

show route-map

Glossary

MPLS VPN Inter-AS—IPv4 BGP Label Distribution

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Feature History

Release	Modification
12.0(21)ST	This feature was introduced.

This feature enables you to set up a VPN service provider network so that the autonomous system boundary routers (ASBRs) exchange IPv4 routes with MPLS labels of the provider edge (PE) routers. Route reflectors (RRs) exchange VPNv4 routes, using multihop, multiprotocol, External Border Gateway Protocol (EBGP). This configuration saves the ASBRs from having to store all the VPNv4 routes. Using the route reflectors to store the VPNv4 routes and forward them to the PE routers results in improved scalability.

This feature module includes the following sections:

•Feature Overview

•Supported Platforms

•Supported Standards, MIBs, and RFCs

•Prerequisites

•Configuration Tasks

•Configuration Examples

•Command Reference

•Glossary

Feature Overview

This feature enables you to set up a VPN service provider network to exchange IPv4 routes with MPLS labels. You can configure the VPN service provider network as follows:

•Route reflectors exchange VPNv4 routes, using multihop, multiprotocol EBGP. This configuration also preserves the next hop information and the VPN labels across the autonomous systems.

•A local PE router (for example, PE1 in Figure 1) needs to know the routes and label information for the remote PE router (PE2). This information can be exchanged between the PE routers and ASBRs in one of two ways:

–Internal Gateway Protocol (IGP) and Label Distribution Protocol (LDP): The ASBR can redistribute the IPv4 routes and MPLS labels it learned from EBGP into IGP and LDP and vice versa.

–Internal Border Gateway Protocol (IBGP) IPv4 label distribution: The ASBR and PE router can use direct IBGP sessions to exchange VPNv4 and IPv4 routes and MPLS labels.

Alternatively, the route reflector can reflect the IPv4 routes and MPLS labels learned from the ASBR to the PE routers in the VPN. This is accomplished by enabling the ASBR to exchange IPv4 routes and MPLS labels with the route reflector. The route reflector also reflects the VPNv4 routes to the PE routers in the VPN (as mentioned in the first bullet). For example, in VPN1, RR1 reflects to PE1 the VPNv4 routes it learned and IPv4 routes and MPLS labels learned from ASBR1. Using the route reflectors to store the VPNv4 routes and forward them through the PE routers and ASBRs allows for a scalable configuration.

•ASBRs exchange IPv4 routes and MPLS labels for the PE routers, using EBGP.

Figure 1 VPNs Using EBGP and IBGP to Distribute Routes and MPLS Labels

BGP Overview

BGP routing information includes the following items:

•A network number (prefix), which is the IP address of the destination.

•Autonomous system (AS) path, which is a list of the other ASs through which a route passes on its way to the local router. The first AS in the list is closest to the local router; the last AS in the list is farthest from the local router and usually the AS where the route began.

•Path attributes, which provide other information about the AS path, for example, the next hop.

Types of BGP Messages

MPLS labels are included in the "update" messages that a router sends. Routers exchange the following types of BGP messages:

•Open Messages—After a router establishes a TCP connection with a neighboring router, the routers exchange "open" messages. This message contains the AS number to which the router belongs and the IP address of the router who sent the message.

•Update Messages—When a router has a new, changed, or broken route, it sends an "update" message to the neighboring router. This message contains the Network Layer Reachability Information (NLRI), which lists the IP addresses of the usable routes. The update message also includes any routes that are no longer usable. The update message also includes path attributes and the lengths of both the usable and unusable paths. Labels for VPNv4 routes are encoded in the update message as specified in RFC 2858. The labels for the IPv4 routes are encoded in the update message as specified in RFC 3107.

•Keepalive Messages—Routers exchange "keepalive" messages to determine if a neighboring router is still available to exchange routing information. The router sends these messages at regular intervals. (Sixty seconds is the default for Cisco routers.) The keepalive message does not contain routing data; it only contains a message header.

•Notification Messages—When a router detects an error, it sends a "notification" message.

How BGP Sends MPLS Labels with Routes

When BGP (External BGP (EBGP) and Internal BGP (IBGP)) distributes a route, it can also distribute an MPLS label that is mapped to that route. The MPLS label mapping information for the route is carried in the BGP update message that contains the information about the route. If the next hop is not changed, the label is preserved.

When you issue the neighbor send-label command on both BPG routers, the routers advertise to each other that they can then send MPLS labels with the routes. If the routers successfully negotiate their ability to send MPLS labels, the routers add MPLS labels to all outgoing BGP updates.

Using Route Maps to Filter Routes

When both routers are configured to distribute routes with MPLS labels, all the routes are encoded with the multiprotocol extensions and contain an MPLS label. You can use a route map to control the distribution of MPLS labels between routers. Route maps enable you to specify the following:

•For a router distributing MPLS labels, you can specify which routes are distributed with an MPLS label.

•For a router receiving MPLS labels, you can specify which routes are accepted and installed in the BGP table.

Benefits

Using BGP to distribute IPv4 routes and MPLS labels routes has the following benefits:

Having the route reflectors store VPNv4 routes results in improved scalability

This configuration scales better than other configurations where the ASBR holds all of the VPNv4 routes and forwards based on VPNv4 labels. With this configuration, route reflectors hold the VPNv4 routes, which simplifies the configuration at the border of the network.

Enables a non-VPN core network to act as a transit network for VPN traffic.

The configuration example illustrated in Figure 5 shows that you can transport IPv4 routes with MPLS labels over a non MPLS VPN service provider.

Eliminates the need for any other label distribution protocol between adjacent LSRs

If two adjacent label switch routers (LSRs) are also BGP peers, BGP can handle the distribution of the MPLS labels. No other label distribution protocol is needed between the two LSRs.

Restrictions

This feature includes the following restrictions:

•For networks configured with EBGP multihop, an LSP must be established between nonadjacent routers. (RFC 3107)

•This feature does not currently support multiple routes to a given destination.

•The PE routers must run images that support BGP label distribution. Otherwise, you cannot run EBGP between them.

•This feature is not supported with eiBGP multipath.

•The physical interfaces that connect the BGP speakers must support Cisco Express Forwarding (CEF) or distributed CEF and MPLS.

Related Features and Technologies

The Inter-Autonomous Systems for MPLS VPNs feature is used with the VPN capabilities of MPLS. MPLS VPNs were introduced in Cisco IOS Release 12.0(5)T.

This feature is an extension of the Inter-Autonomous Systems for MPLS VPNs, Release 12.0(17)ST.

Related Documents

•Inter-Autonomous Systems for MPLS VPNs

•Cisco IOS IP Configuration Guide, Release 12.2, Configuring BGP chapter

•Using the Border Gateway Protocol for Interdomain Routing

•Internetworking Technology Overview, Border Gateway Protocol chapter

•Cisco IOS Switching Services Configuration Guide, Release 12.2, Configuring Multiprotocol Label Switching chapter

•Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2, BGP Commands chapter

•MPLS Virtual Private Networks

Supported Platforms

The following router platforms are supported at the service provider edge:

•Cisco 7200 series

•Cisco 7500 series

Determining Platform Support Through Cisco Feature Navigator

Cisco IOS software is packaged in feature sets that support specific platforms. To get updated information regarding platform support for this feature, access Cisco Feature Navigator. Cisco Feature Navigator dynamically updates the list of supported platforms as new platform support is added for the feature.

Cisco Feature Navigator is a web-based tool that enables you to quickly determine which Cisco IOS software images support a specific set of features and which features are supported in a specific Cisco IOS image. You can search by feature or release. Under the release section, you can compare releases side by side to display both the features unique to each software release and the features in common.

To access Cisco Feature Navigator, you must have an account on Cisco.com. If you have forgotten or lost your account information, send a blank e-mail to cco-locksmith@cisco.com. An automatic check will verify that your e-mail address is registered with Cisco.com. If the check is successful, account details with a new random password will be e-mailed to you. Qualified users can establish an account on Cisco.com by following the directions at http://www.cisco.com/register.

Cisco Feature Navigator is updated regularly when major Cisco IOS software releases and technology releases occur. For the most current information, go to the Cisco Feature Navigator home page at the following URL:

http://www.cisco.com/go/fn

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

•RFC 3107, Carrying Label Information in BGP-4

•RFC 2858, Multiprotocol Extensions for BGP-4

•RFC 1700, Assigned Numbers

•RFC 2842, Capabilities Advertisement with BGP-4

•RFC 1966, BGP Route Reflection: An Alternative to Full Mesh IBGP

Prerequisites

The network must be properly configured for MPLS VPN operation before you configure this feature.

Configuration Tasks

See the following sections for configuration tasks for this feature. Each task in the list is identified as either required or optional.

•Configuring the ASBRs to Exchange IPv4 Routes and MPLS Labels (required)

•Configuring the Route Reflectors to Exchange VPNv4 Routes (required)

•Configuring the Route Reflectors to Reflect Remote Routes in Its AS (optional)

•Creating Route Maps (optional)

•Applying the Route Maps to the ASBRs (optional)

Figure 2 shows the following configuration:

•The configuration consists of two VPNs: VPN1 and VPN2.

•The ASBRs exchange the IPv4 routes with MPLS labels.

•The route reflectors exchange the VPNv4 routes.

•The route reflectors reflect the IPv4 and VPNv4 routes to the other routers in its AS.

Figure 2 Configuring Two VPN Service Providers to Exchange IPv4 Routes and MPLS Labels

Configuring the ASBRs to Exchange IPv4 Routes and MPLS Labels

Use the following procedure to configure the ASBRs so that they can distribute BGP routes with MPLS labels.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enables the BGP routing process and assigns the router to the AS number you specify. The AS number identifies the router to routers in other ASs.
Step 3	Router(config-router)# address-family ipv4	Enters address family submode and enables the exchange of IPv4 NLRI.
Step 4	Router(config-router-af)# neighbor ip-address remote-4 as-number	Specifies the neighboring BGP router and the AS number to which the neighboring BGP router belongs.
Step 5	Router(config-router-af)# neighbor ip-address activate	Enables the router to exchange routes with the neighboring BGP router.
Step 6	Router(config-router-af)# neighbor ip-address send-label	Advertises the router's ability to send MPLS labels with routes.
Step 7	Router(config-router-af)# exit-address-family	Exits from the address family submode.

Configuring the Route Reflectors to Exchange VPNv4 Routes

Use the following procedure to enable the route reflectors to exchange VPNv4 routes, using multihop, multiprotocol EBGP. This procedure also specifies that the next hop information and the VPN label are preserved across the autonomous systems. This procedure uses RR1 as an example.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enables the BGP routing process and assigns RR1 to the AS number you specify. The AS number identifies RR1 to routers in other ASs.
Step 3	Router(config-router)# address-family vpnv4	Enters address family submode and enables the exchange of VPNv4 NLRI.
Step 4	Router(config-router-af)# neighbor ip-address remote-as as-number	Specifies the neighboring BGP router (RR2) and the AS number to which RR2 belongs.
Step 5	Router(config-router-af)# neighbor ip-address ebgp-multihop	Creates a BGP connection to the neighboring BGP router (RR2) and enables EGBP multihop.
Step 6	Router(config-router-af)# neighbor ip-address activate	Enables the exchange of routes with the neighboring BGP router.
Step 7	Router(config-router-af)# neighbor ip-address next-hop unchanged	Forces the next hop information and VPN label to remain the same when VPN routes cross autonomous systems.
Step 8	Router(config-router-af)# exit-address-family	Exits from the address family submode.

Configuring the Route Reflectors to Reflect Remote Routes in Its AS

The following procedure explains how to enable the RR to reflect the IPv4 routes and labels learned by the ASBR to the PE routers in the AS. This is accomplished by making the ASBR and PE router route reflector clients of the RR. This procedure also explains how to enable the RR to reflect the VPNv4 routes.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enables the BGP routing process and assigns the router to the AS number you specify. The AS number identifies the router to routers in other ASs.
Step 3	Router(config-router)# address-family ipv4	Enters address family submode and enables the exchange of IPv4 NLRI.
Step 4	Router(config-router-af)# neighbor ip-address activate	Enables the exchange of routes with the neighboring BGP router.
Step 5	Router(config-router-af)# neighbor ip-address route-reflector-client	Enables the RR to pass IBGP routes to the neighboring router.
Step 6	Router(config-router-af)# neighbor ip-address send-label	Advertises the router's ability to send MPLS labels with routes.
Step 7	Router(config-router-af)# exit-address-family	Exits from the address family submode.
Step 8	Router(config-router)# address-family vpnv4	Enters address family submode and enables the exchange of VPNv4 NLRI.
Step 9	Router(config-router-af)# neighbor ip-address activate	Enables the exchange of routes with the neighboring BGP router.
Step 10	Router(config-router-af)# neighbor ip-address route-reflector-client	Enables the RR to pass IBGP routes to the neighboring router.
Step 11	Router(config-router-af)# exit-address-family	Exits from the address family submode.

Creating Route Maps

The following procedures enable the ASBRs to send MPLS labels with the routes specified in the route maps. Further, the ASBRs accept only the routes that are specified in the route map.

Route maps enable you to specify which routes are distributed with MPLS labels. Route maps also enable you to specify which routes with MPLS labels a router receives and adds to its BGP table.

Route maps work with access lists. You enter the routes into an access list and then specify the access list when you configure the route map.

Configuring a Route Map for Arriving Routes

This procedure explains how to filter routes. You create an access list and specify the routes that the router should accept and add to the BGP table.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enters router configuration mode.
Step 3	Router(config-router)# route-map route-map-name permit sequence-number	Creates a route map with the name you specify. The permit keyword allows the actions to happen if all conditions are met. A deny keyword prevents any actions from happening if all conditions are met. The sequence-number parameter allows you to prioritize route maps. If you have multiple route maps and want to prioritize them, assign each one a number. The route map with the lowest number is implemented first, followed by the route map with the second lowest number, and so on.
Step 4	Router(config-route-map)# match ip address access-list-name	Checks the route listed in the BGP update message against the list of routes in the ACL you specify. If a route in the BGP update message matches a route in the ACL, the route is accepted by the router and added to the BGP table.
Step 5	Router(config-route-map)# match mpls-label	Specifies that the route must have a label to be installed into the BGP table.

Configuring a Route Map for Departing Routes

This procedure explains how to filter routes. You create an access list and specify the routes that the router should distribute with MPLS labels.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enters router configuration mode.
Step 3	Router(config-router)# route-map route-map-name permit sequence-number	Creates a route map with the name you specify. The permit keyword allows the actions to happen if all conditions are met. A deny keyword prevents the actions from happening if all conditions are met. The sequence-number parameter allows you to prioritize route maps. If you have multiple route maps and want to prioritize them, assign each one a number. The route map with the lowest number is implemented first, followed by the route map with the second lowest number, and so on.
Step 4	Router(config-route-map)# match ip address access-list-name	Checks the route listed in the BGP update message against the list of routes in the ACL you specify. If a route in the BGP update message matches a route in the ACL, the router distributes the route.
Step 5	Router(config-route-map)# set mpls-label	Specifies that the router distributes the route with an MPLS label.

Applying the Route Maps to the ASBRs

Use the following procedure to enable the ASBRs to use the route maps.

	Command	Purpose
Step 1	Router# configure terminal	Enters global configuration mode.
Step 2	Router(config)# router bgp as-number	Enters router configuration mode.
Step 3	Router(config-router)# address-family ipv4	Enters address family submode and enables the exchange of IPv4 NLRI.
Step 4	Router(config-router-af)# neighbor ip-address route-map route-map-name in	Applies the route map you specify to the routes that the router receives (incoming routes).
Step 5	Router(config-router-af)# neighbor ip-address route-map route-map-name out	Applies the route map you specify to the routes that the router sends out (outgoing routes).
Step 6	Router(config-router-af)# neighbor ip-address send-label	Advertises the router's ability to send MPLS labels with routes.
Step 7	Router(config-router-af)# exit-address-family	Exits from the address family submode.

Verifying the Configuration

If you use route reflectors to distribute the VPNv4 routes and use the ASBRs to distribute the IPv4 labels, use the following procedures to help verify the configuration. Use Figure 3 as a reference of the configuration.

Figure 3 Configuring Two VPN Service Providers to Exchange IPv4 Routes and MPLS Labels

Verifying the Route Reflector Configuration

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Step 1 Verify the following:

•A multihop, multiprotocol, EBGP session exists between the route reflectors.

•The VPN IPv4 routes are being exchanged between the route reflectors.

The last two lines of the command output show the following information:

•Prefixes are being learned from PE1 and then passed to RR2.

•Prefixes are being learned from RR2 and then passed to PE1.

Router# show ip bgp vpnv4 all summary

BGP router identifier aa.aa.aa.aa, local AS number 100

BGP table version is 238, main routing table version 238

9 network entries and 9 paths using 1629 bytes of memory

13 BGP path attribute entries using 728 bytes of memory

3 BGP AS-PATH entries using 72 bytes of memory

1 BGP extended community entries using 24 bytes of memory

0 BGP route-map cache entries using 0 bytes of memory

0 BGP filter-list cache entries using 0 bytes of memory

BGP activity 256/422 prefixes, 323/305 paths, scan interval 15 secs

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

ee.ee.ee.ee     4   100   43045   43332      238    0    0 4d21h           2 

bb.bb.bb.bb     4   200     547     550      231    0    0 00:00:17        3 

Step 2 Verify that the route reflectors are exchanging VPN-IPv4 label information. In the command output line that starts with nn.nn.nn.nn, label 25 is the VPN label to CE2 (nn.nn). The next hop PE is PE2 (ff.ff).

Router# show ip bgp vpnv4 all labels

Network          Next Hop      In label/Out label

Route Distinguisher: 100:1

oo.oo.oo.oo/32   ee.ee.ee.ee     nolabel/17

nn.nn.nn.nn/32   ff.ff.ff.ff     nolabel/25

ss.0.0.0         ee.ee.ee.ee     nolabel/18

tt.0.0.0         ff.ff.ff.ff     nolabel/26

tt.0.0.1/32      ff.ff.ff.ff     nolabel/24

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Verifying That Routers Exchange Network Reachability Information

The following sections verify that routers CE1, PE1, and PE2 can exchange Network Layer Reachability Information (NLRI) with CE2.

Verifying That CE1 Has Network Reachability Information for CE2

Issue the following commands from CE1 to verify that it has NLRI for CE2.

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Step 1 Verify that CE1 has a route to CE2 (nn.nn).

Router# show ip route nn.nn.nn.nn

Routing entry for nn.nn.nn.nn/32

  Known via "static", distance 1, metric 0

  Routing Descriptor Blocks:

  * ss.0.0.1

      Route metric is 0, traffic share count is 1

Step 2 Verify the routes learned by CE1. Make sure that the route for CE2 (nn.nn) is listed. The command output shows an entry for CE2 (nn.nn.nn.nn).

Router# show ip route

Codes: C - connected, S - static, I - IGRP, 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, E - EGP

       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area

       * - candidate default, U - per-user static route, o - ODR

Gateway of last resort is not set

C    ss.0.0.0/8 is directly connected, Ethernet0/1

     vv.0.0.0/32 is subnetted, 1 subnets

S       nn.nn.nn.nn [1/0] via ss.0.0.1

     xo.0.0.0/32 is subnetted, 1 subnets

C       oo.oo.oo.oo is directly connected, Loopback0

S    tt.0.0.0/8 [1/0] via ss.0.0.1

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Verifying That PE1 Has Network Layer Reachability Information for CE2

Use the following procedures to verify that PE1 has NLRI for CE2.

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Step 1 Verify that PE1 learns CE2's route (nn.nn.nn.nn).

Router# show ip route vrf <vrf-name> nn.nn.nn.nn

Routing entry for nn.nn.nn.nn/32

  Known via "bgp 100", distance 200, metric 0

  Tag 200, type internal

  Last update from ff.ff.ff.ff 00:01:58 ago

  Routing Descriptor Blocks:

  * ff.ff.ff.ff (Default-IP-Routing-Table), from aa.aa.aa.aa, 00:01:58 ago

      Route metric is 0, traffic share count is 1

      AS Hops 2, BGP network version 0

Step 2 Verify that PE2 is the BGP next hop to CE2 (nn.nn), using one of the following commands. Both commands show that PE2 (ff.ff) is the next hop PE.

Router# show ip bgp vpnv4 <vrf-name> nn.nn.nn.nn

BGP routing table entry for 100:1:nn.nn.nn.nn/32, version 876

Paths: (1 available, best #1, table vpn1)

  Not advertised to any peer

  200 400

    ff.ff.ff.ff (metric 20) from aa.aa.aa.aa (aa.aa.aa.aa)   <--ff.ff is the Next-Hop PE

      Origin IGP, localpref 100, valid, internal, best

      Extended Community: RT:100:1

or

Router# show ip bgp vpnv4 all nn.nn.nn.nn

BGP routing table entry for 100:1:nn.nn.nn.nn/32, version 876

Paths: (1 available, best #1, table vpn1)

  Not advertised to any peer

  200 400

    ff.ff.ff.ff (metric 20) from aa.aa.aa.aa (aa.aa.aa.aa)  <--ff.ff is the Next-Hop PE

      Origin IGP, localpref 100, valid, internal, best

      Extended Community: RT:100:1

Step 3 Verify that the Cisco Express Forwarding (CEF) entries are correct.

Router# show ip cef <vrf-name> nn.nn.nn.nn

nn.nn.nn.nn/32, version 280, cached adjacency rr.0.0.2

0 packets, 0 bytes

  tag information set

    local tag: VPN route head

    fast tag rewrite with Et1/4, rr.0.0.2, tags imposed {24 28 25}

  via ff.ff.ff.ff, 0 dependencies, recursive

    next hop rr.0.0.2, Ethernet1/4 via ff.ff.ff.ff/32

    valid cached adjacency

    tag rewrite with Et1/4, rr.0.0.2, tags imposed {24 28 25}

The command output shows a three-level label stack, which is explained as follows:

•24 is the outgoing label to the BGP next-hop router (ASBR2). This allows the packet to be forwarded across the AS boundary (similar to regular Inter-AS).

•28 is the label to the remote egress PE router (PE2), which is advertising the VPNv4 route of CE2 (nn.nn).

•25 is the VPN label for CE2 (nn.nn), as advertised by PE2.

The following commands provide more information about labels 24, 28, and 25.

Step 4 Verify that 24 is the IGP label to the BGP next hop router (AS boundary). This is shown in the last line of the command output.

Router# show mpls forwarding

Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop    

tag    tag or VC   or Tunnel Id      switched   interface              

16     Pop tag     aa.aa.aa.aa/32    4380494    Se6/3      point2point  

17     Untagged    oo.oo.oo.oo/32[V] 851919024  Et1/1      ss.0.0.2     

18     Aggregate   ss.0.0.0/8[V]     41661152                           

19     Pop tag     uu.uu.uu.uu/32    0          Et1/4      rr.0.0.2     

20     Pop tag     gg.0.0.0/8        0          Et1/4      rr.0.0.2     

21     16          ww.ww.ww.ww/32    11575      Et1/4      rr.0.0.2     

22     17          2.0.0.0/8         0          Et1/4      rr.0.0.2     

24     23          hh.0.0.0/8        0          Et1/4      rr.0.0.2     

25     24          hh.0.0.1/32       4737       Et1/4      rr.0.0.2     

Step 5 Verify that 28 is the label to the remote egress PE router (PE2). This is shown in the last line of the command output.

Router# show ip bgp ff.ff.ff.ff

BGP routing table entry for ff.ff.ff.ff/32, version 436

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Not advertised to any peer

  200

    hh.0.0.1 (metric 20) from aa.aa.aa.aa (ww.ww.ww.ww)

      Origin incomplete, metric 101, localpref 100, valid, internal, best

      Originator: ww.ww.ww.ww, Cluster list: 0.0.0.1,

      mpls labels in/out unknown/28                         

Step 6 Verify that 25 is the VPN label to CE2 (nn.nn), as advertised by PE2 (ff.ff). This is shown in the line of the command output that starts with nn.nn.nn.nn.

Router# show ip bgp vpnv4 all labels

Network          Next Hop      In label/Out label

Route Distinguisher: 100:1

oo.oo.oo.oo/32   ee.ee.ee.ee     nolabel/17

nn.nn.nn.nn/32   ff.ff.ff.ff     nolabel/25

ss.0.0.0         ee.ee.ee.ee     nolabel/18

tt.0.0.0         ff.ff.ff.ff     nolabel/26

tt.0.0.1/32      ff.ff.ff.ff     nolabel/24

---

Verifying that PE2 Has Network Reachability Information for CE2

Use the following procedures to ensure that PE2 can access CE2.

---

Step 1 Check the VPN routing and forwarding table for CE2 (nn.nn). The output of the first command provides next hop information. The output of the second command provides the label for CE2 and the outgoing interface.

Router# show ip route <vrf-name> nn.nn.nn.nn 

Routing entry for nn.nn.nn.nn/32

  Known via "bgp 200", distance 20, metric 0

  Tag 400, type external

  Last update from tt.0.0.1 5d15h ago

  Routing Descriptor Blocks:

  * tt.0.0.1, from tt.0.0.1, 5d15h ago 

      Route metric is 0, traffic share count is 1

      AS Hops 1, BGP network version 0

Router# show tag forwarding <vrf-name> nn.nn.nn.nn

Local  Outgoing    Prefix            Bytes tag  Outgoing   Next Hop    

tag    tag or VC   or Tunnel Id      switched   interface              

25     Untagged    nn.nn.nn.nn/32[V] 522612138  Et0/1      tt.0.0.1 

Step 2 Check the VPN label for CE2 (nn.nn) in multiprotocol BGP table. The second line in the command output shows that 25 is the label assigned to CE2.

Router# show ip bgp vpnv4 all labels

   Network          Next Hop      In label/Out label

Route Distinguisher: 100:1 (vpn1)

   oo.oo.oo.oo/32   ee.ee.ee.ee     nolabel/17

   nn.nn.nn.nn/32   tt.0.0.1        25/nolabel 

   ss.0.0.0         ee.ee.ee.ee     nolabel/18

   tt.0.0.0         0.0.0.0         26/aggregate(vpn1)

   tt.0.0.1/32      0.0.0.0         24/nolabel

Step 3 Check the CEF entry for CE2 (nn.nn). The command output shows the local label for CE2 and the outgoing interface.

Router# show ip cef <vrf-name> nn.nn.nn.nn

nn.nn.nn.nn/32, version 73, cached adjacency tt.0.0.1

0 packets, 0 bytes

  tag information set

    local tag: 25 via tt.0.0.1, 0 dependencies, recursive

    next hop tt.0.0.1, Ethernet0/1 via tt.0.0.1/32  

    valid cached adjacency

    tag rewrite with Et0/1, tt.0.0.1, tags imposed {}

---

Verifying the ASBR Configuration

Issue the following commands to verify that the ASBRs exchange IPv4 routes with MPLS labels or IPv4 routes without labels as prescribed by a route map.

---

Step 1 Verify that ASBR1 receives an MPLS label for PE2 (ff.ff) from ASBR2 (xx.xx). The last line of the command output shows label 28, which is the label for PE2.

Router# show ip bgp ff.ff.ff.ff

BGP routing table entry for ff.ff.ff.ff/32, version 13

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Advertised to non peer-group peers:

  aa.aa.aa.aa 

  200

    hh.0.0.1 from hh.0.0.1 (xx.xx.xx.xx)

      Origin incomplete, metric 101, localpref 100, valid, external, best,

      mpls labels in/out unknown/28       <-- 28 is the label to ff.ff

Step 2 Verify that the CEF entry for PE2 (ff.ff) is correct. The last line of the command output shows label 28, which corresponds to the label number in the previous step.

Router# show ip cef ff.ff.ff.ff

ff.ff.ff.ff/32, version 37, cached adjacency hh.0.0.1

0 packets, 0 bytes

  tag information set

    local tag: BGP route head

    fast tag rewrite with Et0/2, hh.0.0.1, tags imposed {28}

  via hh.0.0.1, 0 dependencies, recursive

    next hop hh.0.0.1, Ethernet0/2 via hh.0.0.1/32          <--- N-hop info to ff.ff

    valid cached adjacency

    tag rewrite with Et0/2, hh.0.0.1, tags imposed {28}      <---28 is correct

Step 3 Verify that ASBR1 received from ASBR2 IPv4 routes for RR2 (bb.bb) without labels. The command output does not display MPLS label information, which means that the route was received without an MPLS label.

Router# show ip bgp bb.bb.bb.bb

BGP routing table entry for bb.bb.bb.bb/32, version 11

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Advertised to non peer-group peers:

  aa.aa.aa.aa 

  200

    hh.0.0.1 from hh.0.0.1 (xx.xx.xx.xx)

      Origin incomplete, metric 589, localpref 100, valid, external, best 

Step 4 Verify that the CEF entry for RR2 is correct. The last line of the command output shows that no labels were imposed.

Router# show ip cef bb.bb.bb.bb

bb.bb.bb.bb/32, version 38, cached adjacency hh.0.0.1

0 packets, 0 bytes

  tag information from hh.0.0.1/32, shared

    local tag: 34

  via hh.0.0.1, 0 dependencies, recursive

    next hop hh.0.0.1, Ethernet0/2 via hh.0.0.1/32     <--N-hop info to ff.ff

    valid cached adjacency

    tag rewrite with Et0/2, hh.0.0.1, tags imposed {}  <--- no label: correct

Step 5 Examine MPLS label for PE2 (ff.ff) distributed by ASBR2 (xx.xx) to ASBR1 (ww.ww).

Router# show ip bgp ff.ff.ff.ff

BGP routing table entry for ff.ff.ff.ff/32, version 9

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Advertised to non peer-group peers:

  hh.0.0.2 

  Local

    jj.0.0.2 from 0.0.0.0 (xx.xx.xx.xx)

      Origin incomplete, metric 101, localpref 100, weight 32768, valid, sourced, best,

      mpls labels in/out 28/exp-null  <--- 28 is correct

Step 6 Verify that the CEF entry for PE2 (ff.ff) is correct. The local tag is 28, which is the correct label for PE2.

Router# show ip cef ff.ff.ff.ff

ff.ff.ff.ff/32, version 25, cached adjacency jj.0.0.2

0 packets, 0 bytes

  tag information set

    local tag: 28                            <--- correct

  via jj.0.0.2, Ethernet1/2, 3 dependencies

    next hop jj.0.0.2, Ethernet1/2           <-- N-hop info to ff.ff

    valid cached adjacency

    tag rewrite with Et1/2, jj.0.0.2, tags imposed {}

Step 7 Verify that ASBR2 (xx.xx) does not distribute a label for RR2 (bb.bb) to ASBR1 (ww.ww). The last line of command output shows that no labels were distributed to ASBR1.

Router# show ip bgp bb.bb.bb.bb

BGP routing table entry for bb.bb.bb.bb/32, version 2

Paths: (1 available, best #1, table Default-IP-Routing-Table)

  Advertised to non peer-group peers:

  hh.0.0.2 

  Local

    jj.0.0.2 from 0.0.0.0 (xx.xx.xx.xx)

      Origin incomplete, metric 589, localpref 100, weight 32768, valid, sourced, best,

      mpls labels in/out unknown/exp-null     <--No label distributed to ASBR1

                  ^^^^

Step 8 Verify that the CEF entry for RR2 (bb.bb) is correct.

Router# show ip cef bb.bb.bb.bb

bb.bb.bb.bb/32, version 27, cached adjacency jj.0.0.2

0 packets, 0 bytes

  tag information set

    local tag: 16                              <--label advertised to other IGP peers

    fast tag rewrite with Et1/2, jj.0.0.2, tags imposed {17}

  via jj.0.0.2, Ethernet1/2, 0 dependencies

    next hop jj.0.0.2, Ethernet1/2                       <-- N-hop info to bb.bb

    valid cached adjacency

    tag rewrite with Et1/2, jj.0.0.2, tags imposed {17}  <-- label assigned by an IGP Peer 

                                                             (PE2 possibly or a P router)

---

Configuration Examples

This section provides the following configuration examples:

•Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels

•Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels Over a Non MPLS VPN Service Provider

Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels

Figure 4 shows two MPLS VPN service providers. They distribute VPNv4 addresses between the route reflectors and IPv4 routes and MPLS labels between ASBRs.

The configuration example shows the two techniques you can use to distribute the VPNv4 routes and the IPv4 routes and MPLS labels of remote PEs and RRs to local PEs and RRs:

•AS 100 uses the route reflectors to distribute the IPv4 routes and MPLS labels and the VPNv4 routes from the ASBR to the PE.

•In AS 200, the IPv4 routes that ASBR2 learned are redistributed into IGP.

Figure 4 Distributing IPv4 Routes and MPLS Labels Between MPLS VPN Service Providers

Route Reflector 1 Configuration

The configuration example for RR1 specifies the following:

•RR1 exchanges VPNv4 routes with RR2, using multiprotocol, multihop EBGP.

•The VPNv4 next hop information and the VPN label are preserved across the autonomous systems.

•RR1 reflects to PE1 the VPNv4 routes learned from RR2 and the IPv4 routes and MPLS labels learned from ASBR1.

ip subnet-zero

ip cef

!

interface Loopback0

 ip address aa.aa.aa.aa 255.255.255.255

 no ip directed-broadcast

!

interface Serial1/2

 ip address dd.0.0.2 255.0.0.0

 no ip directed-broadcast

 clockrate 124061

!   

router ospf 10

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 network aa.aa.aa.aa 0.0.0.0 area 100

 network dd.0.0.0 0.255.255.255 area 100

!

router bgp 100

 bgp cluster-id 1

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor ee.ee.ee.ee remote-as 100

 neighbor ee.ee.ee.ee update-source Loopback0

 neighbor ww.ww.ww.ww remote-as 100

 neighbor ww.ww.ww.ww update-source Loopback0

 neighbor bb.bb.bb.bb remote-as 200

 neighbor bb.bb.bb.bb ebgp-multihop 255

 neighbor bb.bb.bb.bb update-source Loopback0

 no auto-summary

 !

address-family ipv4

 neighbor ee.ee.ee.ee activate

 neighbor ee.ee.ee.ee route-reflector-client                !IPv4+labels session to PE1

 neighbor ee.ee.ee.ee send-label

 neighbor ww.ww.ww.ww activate

 neighbor ww.ww.ww.ww route-reflector-client                !IPv4+labels session to ASBR1

 neighbor ww.ww.ww.ww send-label

 no neighbor bb.bb.bb.bb activate

 no auto-summary

 no synchronization

 exit-address-family

 !

 address-family vpnv4

 neighbor ee.ee.ee.ee activate

 neighbor ee.ee.ee.ee route-reflector-client                !VPNv4 session with PE1

 neighbor ee.ee.ee.ee send-community extended

 neighbor bb.bb.bb.bb activate             

 neighbor bb.bb.bb.bb next-hop-unchanged                    !MH-VPNv4 session with RR2

 neighbor bb.bb.bb.bb send-community extended                 with next hop unchanged     

 exit-address-family

!

ip default-gateway 3.3.0.1

no ip classless

!

snmp-server engineID local 00000009020000D0584B25C0

snmp-server community public RO

snmp-server community write RW

no snmp-server ifindex persist

snmp-server packetsize 2048

!

end

ASBR1 Configuration

ASBR1 exchanges IPv4 routes and MPLS labels with ASBR2.

In this example, ASBR1 uses route maps to filter routes.

•A route map called OUT specifies that ASBR1 should distribute PE1's route (ee.ee) with labels and RR1's route (aa.aa) without labels.

•A route map called IN specifies that ASBR1 should accept PE2's route (ff.ff) with labels and RR2's route (bb.bb) without labels.

ip subnet-zero

mpls label protocol tdp

!

interface Loopback0

 ip address ww.ww.ww.ww 255.255.255.255

 no ip directed-broadcast

 no ip route-cache

 no ip mroute-cache

!

interface Ethernet0/2

 ip address hh.0.0.2 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

!

interface Ethernet0/3

 ip address dd.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 mpls label protocol ldp

 tag-switching ip

!

router ospf 10

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 redistribute connected subnets

 passive-interface Ethernet0/2

 network ww.ww.ww.ww 0.0.0.0 area 100

 network dd.0.0.0 0.255.255.255 area 100

router bgp 100

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor aa.aa.aa.aa remote-as 100

 neighbor aa.aa.aa.aa update-source Loopback0

 neighbor hh.0.0.1 remote-as 200

 no auto-summary

 !

!

address-family ipv4                      ! Redistributing IGP into BGP 

redistribute ospf 10                     ! so that PE1 & RR1 loopbacks 

neighbor aa.aa.aa.aa activate            ! get into the BGP table

neighbor aa.aa.aa.aa send-label

neighbor hh.0.0.1 activate

neighbor hh.0.0.1 advertisement-interval 5

neighbor hh.0.0.1 send-label

neighbor hh.0.0.1 route-map IN in        ! accepting routes specified in route map IN.

neighbor hh.0.0.1 route-map OUT out      ! distributing routes specified in route map OUT. 
no auto-summary

no synchronization

exit-address-family

!

ip default-gateway 3.3.0.1

ip classless

!

access-list 1 permit ee.ee.ee.ee log                !Setting up the access lists.

access-list 2 permit ff.ff.ff.ff log

access-list 3 permit aa.aa.aa.aa log

access-list 4 permit bb.bb.bb.bb log

route-map IN permit 10                              !Setting up the route maps.

 match ip address 2

 match mpls-label

!

route-map IN permit 11

 match ip address 4

!

route-map OUT permit 12

 match ip address 3

!

route-map OUT permit 13

 match ip address 1

 set mpls-label

!

end

Route Reflector 2 Configuration

RR2 exchanges VPNv4 routes with RR1 through multihop, multiprotocol EBGP. This configuration also specifies that the next hop information and the VPN label are preserved across the autonomous systems.

ip subnet-zero

ip cef

!

interface Loopback0

 ip address bb.bb.bb.bb 255.255.255.255

 no ip directed-broadcast

!

interface Serial1/1

 ip address ii.0.0.2 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

!

router ospf 20

 log-adjacency-changes

 network bb.bb.bb.bb 0.0.0.0 area 200

 network ii.0.0.0 0.255.255.255 area 200

!

router bgp 200

 bgp cluster-id 1

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor aa.aa.aa.aa remote-as 100

 neighbor aa.aa.aa.aa ebgp-multihop 255

 neighbor aa.aa.aa.aa update-source Loopback0

 neighbor ff.ff.ff.ff remote-as 200

 neighbor ff.ff.ff.ff update-source Loopback0

 no auto-summary

 !

 address-family vpnv4

 neighbor aa.aa.aa.aa activate

 neighbor aa.aa.aa.aa next-hop-unchanged              !Multihop VPNv4 session with RR1 

 neighbor aa.aa.aa.aa send-community extended              with next-hop-unchanged

 neighbor ff.ff.ff.ff activate

 neighbor ff.ff.ff.ff route-reflector-client          !VPNv4 session with PE2

 neighbor ff.ff.ff.ff send-community extended

 exit-address-family

!

ip default-gateway 3.3.0.1

no ip classless

!

end

ASBR2 Configuration

ASBR2 exchanges IPv4 routes and MPLS labels with ASBR1. However, in contrast to ASBR1, ASBR2 does not use the RR to reflect IPv4 routes and MPLS labels to PE2. ASBR2 redistributes the IPv4 routes and MPLS labels learned from ASBR1 into IGP. PE2 can now reach these prefixes.

ip subnet-zero

ip cef

!

mpls label protocol tdp

!

interface Loopback0

 ip address xx.xx.xx.xx 255.255.255.255

 no ip directed-broadcast

!

interface Ethernet1/0

 ip address hh.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

!

interface Ethernet1/2

 ip address jj.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 mpls label protocol tdp

 tag-switching ip

 !

router ospf 20

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 redistribute connected subnets

 redistribute bgp 200 subnets           ! redistributing the routes learned from 

 passive-interface Ethernet1/0                ASBR1(EBGP+labels session) into IGP 

 network xx.xx.xx.xx 0.0.0.0 area 200         so that PE2 will learn them  

 network jj..0.0 0.255.255.255 area 200

 !

router bgp 200

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor bb.bb.bb.bb remote-as 200

 neighbor bb.bb.bb.bb update-source Loopback0

 neighbor hh.0.0.2 remote-as 100

 no auto-summary

 !

address-family ipv4

 redistribute ospf 20                         ! Redistributing IGP into BGP  

 neighbor hh.0.0.2 activate                   ! so that PE2 & RR2 loopbacks

 neighbor hh.0.0.2 advertisement-interval 5   ! will get into the BGP-4 table.

 neighbor hh.0.0.2 route-map IN in 

 neighbor hh.0.0.2 route-map OUT out

 neighbor hh.0.0.2 send-label

 no auto-summary

 no synchronization

 exit-address-family

 ! 

 address-family vpnv4

 neighbor bb.bb.bb.bb activate

 neighbor bb.bb.bb.bb send-community extended

 exit-address-family

 !

ip default-gateway 3.3.0.1

ip classless

!

access-list 1 permit ff.ff.ff.ff log          !Setting up the access lists.

access-list 2 permit ee.ee.ee.ee log

access-list 3 permit bb.bb.bb.bb log

access-list 4 permit aa.aa.aa.aa log

route-map IN permit 11                       !Setting up the route maps. 

 match ip address 2

 match mpls-label

!

route-map IN permit 12

 match ip address 4

!

route-map OUT permit 10

 match ip address 1

 set mpls-label

!

route-map OUT permit 13

 match ip address 3

end

Configuring Inter-AS Using BGP to Distribute Routes and MPLS Labels Over a Non MPLS VPN Service Provider

Figure 5 shows two MPLS VPN service providers that are connected through a non MPLS VPN service provider. The autonomous system in the middle of the network is configured as a backbone autonomous system that uses Label Distribution Protocol (LDP) or Tag Distribution Protocol (TDP) to distribute MPLS labels. You can also use traffic engineering tunnels instead of TDP or LDP to build the LSP across the non MPLS VPN service provider.

Figure 5 Distributing Routes and MPLS Labels Over a Non MPLS VPN Service Provider

Route Reflector 1 Configuration

The configuration example for RR1 specifies the following:

•RR1 exchanges VPNv4 routes with RR2, using multiprotocol, multihop EBGP.

•The VPNv4 next hop information and the VPN label are preserved across the autonomous systems.

•RR1 reflects to PE1 the VPNv4 routes learned from RR2 and the IPv4 routes and MPLS labels learned from ASBR1.

ip subnet-zero

ip cef

!

interface Loopback0

 ip address aa.aa.aa.aa 255.255.255.255

 no ip directed-broadcast

!

interface Serial1/2

 ip address dd.0.0.2 255.0.0.0

 no ip directed-broadcast

 clockrate 124061

!   

router ospf 10

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 network aa.aa.aa.aa 0.0.0.0 area 100

 network dd.dd.0.0.0 0.255.255.255 area 100

!

router bgp 100

 bgp cluster-id 1

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor ee.ee.ee.ee remote-as 100

 neighbor ee.ee.ee.ee update-source Loopback0

 neighbor ww.ww.ww.ww remote-as 100

 neighbor ww.ww.ww.ww update-source Loopback0

 neighbor bb.bb.bb.bb remote-as 200

 neighbor bb.bb.bb.bb ebgp-multihop 255

 neighbor bb.bb.bb.bb update-source Loopback0

 no auto-summary

 !

address-family ipv4

 neighbor ee.ee.ee.ee activate

 neighbor ee.ee.ee.ee route-reflector-client                !IPv4+labels session to PE1

 neighbor ee.ee.ee.ee send-label

 neighbor ww.ww.ww.ww activate

 neighbor ww.ww.ww.ww route-reflector-client                !IPv4+labels session to ASBR1

 neighbor ww.ww.ww.ww send-label

 no neighbor bb.bb.bb.bb activate

 no auto-summary

 no synchronization

 exit-address-family

 !

 address-family vpnv4

 neighbor ee.ee.ee.ee activate

 neighbor ee.ee.ee.ee route-reflector-client               !VPNv4 session with PE1

 neighbor ee.ee.ee.ee send-community extended

 neighbor bb.bb.bb.bb activate             

 neighbor bb.bb.bb.bb next-hop-unchanged                    !MH-VPNv4 session with RR2

 neighbor bb.bb.bb.bb send-community extended                 with next-hop-unchanged     

 exit-address-family

!

ip default-gateway 3.3.0.1

no ip classless

!

snmp-server engineID local 00000009020000D0584B25C0

snmp-server community public RO

snmp-server community write RW

no snmp-server ifindex persist

snmp-server packetsize 2048

!

end

ASBR1 Configuration

ASBR1 exchanges IPv4 routes and MPLS labels with ASBR2.

In this example, ASBR1 uses route maps to filter routes.

•A route map called OUT specifies that ASBR1 should distribute PE1's route (ee.ee) with labels and RR1's route (aa.aa) without labels.

•A route map called IN specifies that ASBR1 should accept PE2's route (ff.ff) with labels and RR2's route (bb.bb) without labels.

ip subnet-zero

ip cef distributed

mpls label protocol tdp

!

interface Loopback0

 ip address ww.ww.ww.ww 255.255.255.255

 no ip directed-broadcast

 no ip route-cache

 no ip mroute-cache

!

interface Serial3/0/0

 ip address kk.0.0.2 255.0.0.0

 no ip directed-broadcast

 ip route-cache distributed

!

interface Ethernet0/3

 ip address dd.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 mpls label protocol ldp

 tag-switching ip

!

router ospf 10

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 redistribute connected subnets

 passive-interface Serial3/0/0

 network ww.ww.ww.ww 0.0.0.0 area 100

 network dd.0.0.0 0.255.255.255 area 100

router bgp 100

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor aa.aa.aa.aa remote-as 100

 neighbor aa.aa.aa.aa update-source Loopback0

 neighbor kk.0.0.1 remote-as 200

 no auto-summary

!

 address-family ipv4

 redistribute ospf 10                      ! Redistributing IGP into BGP  

 neighbor aa.aa.aa.aa activate             ! so that PE1 & RR1 loopbacks

 neighbor aa.aa.aa.aa send-label           ! get into BGP table

 neighbor kk.0.0.1 activate

 neighbor kk.0.0.1 advertisement-interval 5

 neighbor kk.0.0.1 send-label

 neighbor kk.0.0.1 route-map IN in    ! Accepting routes specified in route map IN

 neighbor kk.0.0.1 route-map OUT out  ! Distributing routes specified in route map OUT

 no auto-summary

 no synchronization

 exit-address-family

!

ip default-gateway 3.3.0.1

ip classless

!

access-list 1 permit ee.ee.ee.ee log

access-list 2 permit ff.ff.ff.ff log

access-list 3 permit aa.aa.aa.aa log

access-list 4 permit bb.bb.bb.bb log

!

route-map IN permit 10

 match ip address 2

 match mpls-label

!

route-map IN permit 11

 match ip address 4

!

route-map OUT permit 12

 match ip address 3

!

route-map OUT permit 13

 match ip address 1

 set mpls-label

!

end

Route Reflector 2 Configuration

RR2 exchanges VPNv4 routes with RR1, using multihop, multiprotocol EBGP. This configuration also specifies that the next hop information and the VPN label are preserved across the autonomous systems.

ip subnet-zero

ip cef

! 

interface Loopback0

 ip address bb.bb.bb.bb 255.255.255.255

 no ip directed-broadcast

!

interface Serial1/1

 ip address ii.0.0.2 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

!

router ospf 20

 log-adjacency-changes

 network bb.bb.bb.bb 0.0.0.0 area 200

 network ii.0.0.0 0.255.255.255 area 200

!

router bgp 200

 bgp cluster-id 1

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor aa.aa.aa.aa remote-as 100

 neighbor aa.aa.aa.aa ebgp-multihop 255

 neighbor aa.aa.aa.aa update-source Loopback0

 neighbor ff.ff.ff.ff remote-as 200

 neighbor ff.ff.ff.ff update-source Loopback0

 no auto-summary

 !

 address-family vpnv4

 neighbor aa.aa.aa.aa activate

 neighbor aa.aa.aa.aa next-hop-unchanged              !MH Vpnv4 session with RR1 

 neighbor aa.aa.aa.aa send-community extended              with next-hop-unchanged

 neighbor ff.ff.ff.ff activate

 neighbor ff.ff.ff.ff route-reflector-client          !Vpnv4 session with PE2

 neighbor ff.ff.ff.ff send-community extended

 exit-address-family

!

ip default-gateway 3.3.0.1

no ip classless

!

end

ASBR2 Configuration

ASBR2 exchanges IPv4 routes and MPLS labels with ASBR1. However, in contrast to ASBR1, ASBR2 does not use the RR to reflect IPv4 routes and MPLS labels to PE2. ASBR2 redistributes the IPv4 routes and MPLS labels learned from ASBR1 into IGP. PE2 can now reach these prefixes.

ip subnet-zero

ip cef

!

mpls label protocol tdp

!

interface Loopback0

 ip address xx.xx.xx.xx 255.255.255.255

 no ip directed-broadcast

!

interface Ethernet0/1

 ip address qq.0.0.2 255.0.0.0

 no ip directed-broadcast

!

interface Ethernet1/2

 ip address jj.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 mpls label protocol tdp

 tag-switching ip

 !

router ospf 20

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 redistribute connected subnets

 redistribute bgp 200 subnets            !redistributing the routes learned from 

 passive-interface Ethernet0/1                ASBR4(EBGP+labels session) into IGP 

 network xx.xx.xx.xx 0.0.0.0 area 200         so that PE2 will learn them  

 network jj.0.0.0 0.255.255.255 area 200

 !

router bgp 200

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor bb.bb.bb.bb remote-as 200

 neighbor bb.bb.bb.bb update-source Loopback0

 neighbor qq.0.0.1 remote-as 100

 no auto-summary

! 

address-family ipv4                          ! Redistributing IGP into BGP                                                                                 
redistribute ospf 20                         ! so that PE2 & RR2 loopbacks

 neighbor qq.0.0.1 activate                  !  will get into the BGP-4 table

 neighbor qq.0.0.1 advertisement-interval 5

 neighbor qq.0.0.1 route-map IN in

 neighbor qq.0.0.1 route-map OUT out

 neighbor qq.0.0.1 send-label

 no auto-summary

 no synchronization

 exit-address-family

 ! 

address-family vpnv4

 neighbor bb.bb.bb.bb activate

 neighbor bb.bb.bb.bb send-community extended

 exit-address-family

 !

ip default-gateway 3.3.0.1

ip classless

!

access-list 1 permit ff.ff.ff.ff log

access-list 2 permit ee.ee.ee.ee log

access-list 3 permit bb.bb.bb.bb log

access-list 4 permit aa.aa.aa.aa log

!

route-map IN permit 11

 match ip address 2

 match mpls-label

!

route-map IN permit 12

 match ip address 4

!

route-map OUT permit 10

 match ip address 1

 set mpls-label

!

route-map OUT permit 13

 match ip address 3

!

end

ASBR3 Configuration

ASBR3 belongs to a non MPLS VPN service provider. ASBR3 exchanges IPv4 routes and MPLS labels with ASBR1. ASBR3 also passes the routes learned from ASBR1 to ASBR3 through RR3.

---

Note Do not redistribute EBGP routes learned into IBG if you are using IBGP to distribute the routes and labels. This is not a supported configuration.

---

ip subnet-zero

ip cef

!

interface Loopback0

 ip address yy.yy.yy.yy 255.255.255.255

 no ip directed-broadcast

 no ip route-cache

 no ip mroute-cache

!

interface Hssi4/0

 ip address mm.0.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 tag-switching ip

 hssi internal-clock

 !

interface Serial5/0

 ip address kk.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

 load-interval 30

 clockrate 124061

!

router ospf 30

log-adjacency-changes

auto-cost reference-bandwidth 1000

redistribute connected subnets

network yy.yy.yy.yy 0.0.0.0 area 300 

network mm.0.0.0 0.255.255.255 area 300 

!

router bgp 300

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor cc.cc.cc.cc remote-as 300

 neighbor cc.cc.cc.cc update-source Loopback0

 neighbor kk.0.0.2 remote-as 100

 no auto-summary

 !

 address-family ipv4

 neighbor cc.cc.cc.cc activate            ! IBGP+labels session with RR3

 neighbor cc.cc.cc.cc send-label

 neighbor kk.0.0.2 activate               ! EBGP+labels session with ASBR1

 neighbor kk.0.0.2 advertisement-interval 5

 neighbor kk.0.0.2 send-label

neighbor kk.0.0.2 route-map IN in 

neighbor kk.0.0.2 route-map OUT out 

no auto-summary

 no synchronization

 exit-address-family

!

ip classless 

! 

access-list 1 permit ee.ee.ee.ee log 

access-list 2 permit ff.ff.ff.ff log 

access-list 3 permit aa.aa.aa.aa log 

access-list 4 permit bb.bb.bb.bb log 

! 

route-map IN permit 10 

 match ip address 1 

  match mpls-label 

! 

route-map IN permit 11 

   match ip address 3 

! 

route-map OUT permit 12 

 match ip address 2 

  set mpls-label 

! 

route-map OUT permit 13 

   match ip address 4 

! 

ip default-gateway 3.3.0.1

ip classless

!

end

Route Reflector 3 Configuration

RR3 is a non MPLS VPN RR that reflects IPv4 routes with MPLS labels to ASBR3 and ASBR4.

ip subnet-zero

mpls label protocol tdp

mpls traffic-eng auto-bw timers

no tag-switching ip

!

interface Loopback0

 ip address cc.cc.cc.cc 255.255.255.255

 no ip directed-broadcast

!

interface POS0/2

 ip address pp.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip route-cache cef

 no ip route-cache

 no ip mroute-cache

 crc 16

 clock source internal

!

router ospf 30

 log-adjacency-changes

 network cc.cc.cc.cc 0.0.0.0 area 300

 network pp.0.0.0 0.255.255.255 area 300

!

router bgp 300

 bgp log-neighbor-changes

 neighbor zz.zz.zz.zz remote-as 300

 neighbor zz.zz.zz.zz update-source Loopback0

 neighbor yy.yy.yy.yy remote-as 300

 neighbor yy.yy.yy.yy update-source Loopback0

 no auto-summary

 !

address-family ipv4

 neighbor zz.zz.zz.zz activate

 neighbor zz.zz.zz.zz route-reflector-client   

 neighbor zz.zz.zz.zz send-label               ! IBGP+labels session with ASBR3 

 neighbor yy.yy.yy.yy activate                 

 neighbor yy.yy.yy.yy route-reflector-client

 neighbor yy.yy.yy.yy send-label               ! IBGP+labels session with ASBR4

 no auto-summary

 no synchronization

 exit-address-family

!

ip default-gateway 3.3.0.1

ip classless

!

end 

ASBR4 Configuration

ASBR4 belongs to a non MPLS VPN service provider. ASBR4 and ASBR3 exchange IPv4 routes and MPLS labels by means of RR3.

---

Note Do not redistribute EBGP routes learned into IBG if you are using IBGP to distribute the routes and labels. This is not a supported configuration.

---

ip subnet-zero

ip cef distributed

!

interface Loopback0

 ip address zz.zz.zz.zz 255.255.255.255

 no ip directed-broadcast

 no ip route-cache

 no ip mroute-cache

!

interface Ethernet0/2

 ip address qq.0.0.1 255.0.0.0

 no ip directed-broadcast

 no ip mroute-cache

!

interface POS1/1/0

 ip address pp.0.0.2 255.0.0.0

 no ip directed-broadcast

 ip route-cache distributed

 !

interface Hssi2/1/1

 ip address mm.0.0.2 255.0.0.0

 no ip directed-broadcast

 ip route-cache distributed

 no ip mroute-cache

 mpls label protocol tdp

 tag-switching ip

 hssi internal-clock

!

router ospf 30

 log-adjacency-changes

 auto-cost reference-bandwidth 1000

 redistribute connected subnets

passive-interface Ethernet0/2

 network zz.zz.zz.zz 0.0.0.0 area 300

 network pp.0.0.0 0.255.255.255 area 300

 network mm.0.0.0 0.255.255.255 area 300

 !

router bgp 300

 bgp log-neighbor-changes

 timers bgp 10 30

 neighbor cc.cc.cc.cc remote-as 300

 neighbor cc.cc.cc.cc update-source Loopback0

 neighbor qq.0.0.2 remote-as 200

 no auto-summary

 !

 address-family ipv4

 neighbor cc.cc.cc.cc activate

 neighbor cc.cc.cc.cc send-label

 neighbor qq.0.0.2 activate

 neighbor qq.0.0.2 advertisement-interval 5

 neighbor qq.0.0.2 send-label

neighbor qq.0.0.2 route-map IN in 

neighbor qq.0.0.2 route-map OUT out 

no auto-summary

 no synchronization

 exit-address-family

!

ip classless 

! 

access-list 1 permit ff.ff.ff.ff log 

access-list 2 permit ee.ee.ee.ee log 

access-list 3 permit bb.bb.bb.bb log 

access-list 4 permit aa.aa.aa.aa log 

! 

route-map IN permit 10 

 match ip address 1 

  match mpls-label 

! 

route-map IN permit 11 

   match ip address 3 

! 

route-map OUT permit 12 

 match ip address 2 

  set mpls-label 

! 

route-map OUT permit 13 

   match ip address 4 

!

ip default-gateway 3.3.0.1

ip classless

!

end

Command Reference

This section documents new or modified commands. All other commands used with this feature are documented in the Cisco IOS Release 12.2 command reference publications.

New Commands

•match mpls-label

•neighbor send-label

•set mpls-label

•show ip bgp labels

Modified Commands

•debug ip bgp

•show ip bgp

•show ip bgp neighbors

•show ip bgp vpnv4

•show route-map

debug ip bgp

To display information related to processing of the Border Gateway Protocol (BGP), use the debug ip bgp command in privileged EXEC mode. To disable the display of BGP information, use the no form of this command.

debug ip bgp [A.B.C.D. | dampening | events | in | keepalives | out | updates | vpnv4 | mpls]

no debug ip bgp [A.B.C.D. | dampening | events | in | keepalives | out | updates | vpnv4 | mpls]

Syntax Description

A.B.C.D.	(Optional) Displays the BGP neighbor IP address.
dampening	(Optional) Displays BGP dampening.
events	(Optional) Displays BGP events.
in	(Optional) Displays BGP inbound information.
keepalives	(Optional) Displays BGP keepalives.
out	(Optional) Displays BGP outbound information.
updates	(Optional) Displays BGP updates.
vpnv4	(Optional) Displays VPNv4 NLRI information.
mpls	(Optional) Displays the MPLS information.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(5)T	This command was introduced.
12.0(21)ST	This command was updated with the mpls keyword.

Examples

The following example displays the output from this command:

Router# debug ip bgp vpnv4 

03:47:14:vpn:bgp_vpnv4_bnetinit:100:2:58.0.0.0/8

03:47:14:vpn:bnettable add:100:2:58.0.0.0 / 8

03:47:14:vpn:bestpath_hook route_tag_change for vpn2:58.0.0.0/255.0.0.0(ok)

03:47:14:vpn:bgp_vpnv4_bnetinit:100:2:57.0.0.0/8

03:47:14:vpn:bnettable add:100:2:57.0.0.0 / 8

03:47:14:vpn:bestpath_hook route_tag_change for vpn2:57.0.0.0/255.0.0.0(ok)

03:47:14:vpn:bgp_vpnv4_bnetinit:100:2:14.0.0.0/8

03:47:14:vpn:bnettable add:100:2:14.0.0.0 / 8

03:47:14:vpn:bestpath_hook route_tag_chacle ip bgp *nge for vpn2:14.0.0.0/255.0.0.0(ok)

match mpls-label

To redistribute routes that include Multiprotocol Label Switching (MPLS) labels if the routes meet the conditions specified in the route map, use the match mpls-label command in route map configuration mode. To disable this function, use the no form of this command.

match mpls-label

no match mpls-label

Syntax Description

This command has no arguments or keywords.

Defaults

This command has no default behavior or values.

Command Modes

Route map configuration

Command History

Release	Modification
12.0(21)ST	This command was introduced.

Usage Guidelines

A route map that includes this command can be used in the following instances:

•With the neighbor route-map in command to manage inbound route maps in BGP

•With the redistribute bgp command to redistribute route maps in an IGP

Use the route-map global configuration command, and the match and set route map configuration commands, to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

The match route-map configuration command has multiple formats. The match commands can be given in any order, and all match commands must "pass" to cause the route to be redistributed according to the set actions given with the set commands. The no forms of the match commands remove the specified match criteria.

When you are passing routes through a route map, a route map can have several parts. Any route that does not match at least one match clause relating to a route-map command will be ignored; that is, the route will not be advertised for outbound route maps and will not be accepted for inbound route maps. If you want to modify only some data, you must configure a second route map section with an explicit match specified.

Examples

The following example creates a route map that redistributes routes if the following conditions are met:

•The IP address of the route matches an IP address in ACL 2.

•The route includes an MPLS label.

route-map incoming permit 10

match ip address 2

match mpls-label

Related Commands

Command	Description
match ip address	Distributes any routes that have a destination network number address that is permitted by a standard or extended access list.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.
set mpls-label	Enables a route to be distributed with an MPLS label if the route matches the conditions specified in the route map.

neighbor send-label

To enable a Border Gateway Protocol (BGP) router to send Multiprotocol Label Switching (MPLS) labels with BGP routes to a neighboring BGP router, use the neighbor send-label command in router configuration mode. To disable the BGP router from sending MPLS labels with BGP routes, use the no form of this command.

neighbor {ip-address} send-label

no neighbor {ip-address} send-label

Syntax Description

ip-address

IP address of the neighboring router.

Defaults

By default, BGP routers distribute only BGP routes.

Command Modes

Router configuration

Command History

Release	Modification
12.0(21)ST	This command was introduced.

Usage Guidelines

This command enables a router to use BGP to distribute MPLS labels along with the IPv4 routes to a peer router. You must issue this command on both the local router and the neighboring router.

This command has the following restrictions:

•If a BGP session is running when you issue the neighbor send-label command, the command does not take effect until the BGP session is restarted.

•You can use this command only with IPv4 addresses.

Examples

The following example enables a router called BGP 1 to send MPLS labels with BGP routes to the neighboring router, whose IP address is 192.168.0.0:

router bgp1

neighbor 192.168.0.0 send-label

Related Commands

Command	Description
neighbor activate	Enables the exchange of IPv4 address information with a BGP neighboring router.

set mpls-label

To enable a route to be distributed with an Multiprotocol Label Switching (MPLS) label if the route matches the conditions specified in the route map, use the set mpls-label command in route map configuration mode. To disable this function, use the no form of this command.

set mpls-label

no set mpls-label

Syntax Description

This command has no arguments or keywords.

Defaults

This command has no default behavior or values.

Command Modes

Route map configuration

Command History

Release	Modification
12.0(21)ST	This command was introduced.

Usage Guidelines

This command can be used only with the neighbor route-map out command to manage outbound route maps for a Border Gateway Protocol (BGP) session.

Use the route-map global configuration command with match and set route-map configuration commands to define the conditions for redistributing routes from one routing protocol into another. Each route-map command has a list of match and set commands associated with it. The match commands specify the match criteria—the conditions under which redistribution is allowed for the current route-map command. The set commands specify the set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met. The no route-map command deletes the route map.

Examples

The following example creates a route map that enables the route to be distributed with a label if the IP address of the route matches an IP address in ACL 1.

route-map incoming permit 10

match ip address 1

set mpls-label

Related Commands

Command	Description
match ip address	Distributes any routes that have a destination network number address that is permitted by a standard or extended access list.
match mpls-label	Redistributes routes that contain MPLS labels and match the conditions specified in the route map.
route-map (IP)	Defines the conditions for redistributing routes from one routing protocol into another, or enables policy routing.

show ip bgp

To display entries in the Border Gateway Protocol (BGP) routing table, use the show ip bgp command in privileged EXEC mode.

show ip bgp [network] [network-mask] [longer-prefixes]

Syntax Description

network	(Optional) Network number, entered to display a particular network in the BGP routing table.
network-mask	(Optional) Displays all BGP routes matching the address and mask pair.
longer-prefixes	(Optional) Displays the route and more specific routes.

Command Modes

Privileged EXEC

Command History

Release	Modification
10.0	This command was introduced.
12.0	The display of prefix advertisement statistics was added.
12.0(6)T	The display of a message indicating support for route refresh capability was added.
12.0(21)ST	This command was updated to show the number of MPLS labels that arrive at and depart from the prefix.

Examples

The following is sample output from the show ip bgp command in privileged EXEC mode:

Router# show ip bgp

BGP table version is 5, local router ID is 10.0.33.34

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path

*> 1.0.0.0          0.0.0.0                  0         32768 ?

*  2.0.0.0          10.0.33.35              10             0 35 ?

*>                  0.0.0.0                  0         32768 ?

*  10.0.0.0         10.0.33.35              10             0 35 ?

*>                  0.0.0.0                  0         32768 ?

*> 192.168.0.0/16   10.0.33.35              10             0 35 ? 

Table 1 describes the significant fields shown in the display.

Table 1 show ip bgp Field Descriptions 

Field	Description
BGP table version	Internal version number of the table. This number increments when the table changes.
local router ID	IP address of the router.
Status codes	Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values: s—The table entry is suppressed. d—The table entry is dampened and will not be advertised to BGP neighbors. h—The table entry does not contain the best path based on historical information. *—The table entry is valid. >—The table entry is the best entry to use for that network. i—The table entry was learned via an IBGP session.
Origin codes	Origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values: i—Entry originated from Interior Gateway Protocol (IGP) and was advertised with a network router configuration command. e—Entry originated from Exterior Gateway Protocol (EGP). ?—Origin of the path is not clear. Usually, this is a router that is redistributed into BGP from an IGP.
Network	IP address of a network entity.
Next Hop	IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.
Metric	If shown, the value of the inter-autonomous system metric.
LocPrf	Local preference value as set with the set local-preference route-map configuration command. The default value is 100.
Weight	Weight of the route as set via autonomous system filters.
Path	Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

The following is sample output from the show ip bgp command in privileged EXEC mode when you specify the longer-prefixes keyword:

Router# show ip bgp 198.92.0.0 255.255.0.0 longer-prefixes

BGP table version is 1738, local router ID is 198.92.72.24

Status codes: s suppressed, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop          Metric LocPrf Weight Path

*> 198.92.0.0       198.92.72.30        8896         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.1.0       198.92.72.30        8796         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.11.0      198.92.72.30       42482         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.14.0      198.92.72.30        8796         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.15.0      198.92.72.30        8696         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.16.0      198.92.72.30        1400         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.17.0      198.92.72.30        1400         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.18.0      198.92.72.30        8876         32768 ?

*                   198.92.72.30                         0 109 108 ?

*> 198.92.19.0      198.92.72.30        8876         32768 ?

*                   198.92.72.30                         0 109 108 ?

The following is sample output from the show ip bgp command in privileged EXEC mode, showing information for prefix 3.0.0.0. The last line of the output shows that MPLS labels are being sent and received.

Router# show ip bgp 3.0.0.0

BGP routing table entry for 3.0.0.0/8, version 628

Paths: (1 available, best #1)

Advertised to peer-groups:

 ebgp

Advertised to non peer-group peers:

 171.69.232.162

109 65000 297 701 80

 171.69.233.56 from 171.69.233.56 (172.19.185.32)

  Origin incomplete, localpref 100, valid, external, best, ref 2

MPLS labels in/out 24/22

---

Note If a prefix has not been advertised to any peer, the display shows "Not advertised to any peer."

---

Related Commands

Command	Description
clear ip bgp	Resets a BGP connection or session.
neighbor soft-reconfiguration	Configures the Cisco IOS software to start storing updates.

show ip bgp labels

To display information about Multiprotocol Label Switching (MPLS) labels from the External Border Gateway Protocol (EBGP) route table, use the show ip bgp labels command in privileged EXEC mode.

show ip bgp labels

Syntax Description

This command has no arguments or keywords.

Defaults

This command has no default behavior or values.

Command Modes

Privileged EXEC

Command History

Release	Modification
12.0(21)ST	This command was introduced.

Usage Guidelines

Use this command to display EBGP labels associated with an autonomous system boundary router (ASBR).

This command displays labels for BGP routes in the default table only. To display labels in the VRF tables, use the show ip bgp vpnv4 {all | vrf vrf-name} command with the optional labels keyword.

Examples

The following example shows output for an ASBR using BGP as a label distribution protocol:

Router# show ip bgp labels

Network          Next Hop         In Label/Out Label

3.3.0.0/16       0.0.0.0          imp-null/exp-null

15.15.15.15/32   15.15.15.15      18/exp-null

16.16.16.16/32   0.0.0.0          imp-null/exp-null

17.17.17.17/32   34.0.0.1         20/exp-null

18.18.18.18/32   43.0.0.1         24/31

18.18.18.18/32   38.0.0.1         24/33

19.19.19.19/32   43.0.0.1         25/32

19.19.19.19/32   38.0.0.1         25/34

20.20.20.20/32   43.0.0.1         21/30

20.20.20.20/32   38.0.0.1         21/32

33.0.0.0         15.15.15.15      19/exp-null

34.0.0.0         0.0.0.0          imp-null/exp-null

35.0.0.0         43.0.0.1         22/29

35.0.0.0         38.0.0.1         22/31

38.0.0.0         0.0.0.0          imp-null/exp-null

38.0.0.1/32      38.0.0.1         17/29

38.0.0.1/32      0.0.0.0          17/exp-null

40.0.0.0         38.0.0.1         26/35

40.0.0.0         43.0.0.1         26/34

42.0.0.0         43.0.0.1         23/28

42.0.0.0         38.0.0.1         23/30

43.0.0.0         0.0.0.0          imp-null/exp-null

43.0.0.1/32      0.0.0.0          16/exp-null

Table 2 describes the significant fields shown in the display.

Table 2 show ip bgp labels Field Descriptions

Field	Description
Network	Displays the network address from the EGBP table.
Next Hop	Specifies the EBGP next hop address.
In Label	Displays the label (if any) assigned by this router.
Out Label	Displays the label assigned by the BGP next hop router.

Related Commands

Command	Description
show ip bgp vpnv4 all labels	Displays all incoming and outgoing labels for each NLRI in the VPNv4 database.
show ip bgp vpnv4 vrf vrf-name labels	Displays all incoming and outgoing labels for each NLRI in the VPNv4 database associated with the named VRF.

show ip bgp neighbors

To display information about the Transmission Control Protocol/Internet Protocol (TCP/IP) and Border Gateway Protocol (BGP) connections to neighbors, use the show ip bgp neighbors command in privileged EXEC mode.

show ip bgp neighbors [neighbor-address] [received-routes | routes | advertised-routes | {paths regexp} | dampened-routes]

Syntax Description

neighbor-address	(Optional) Address of the neighbor whose routes you have learned from. If you omit this argument, all neighbors are displayed.
received-routes	(Optional) Displays all received routes (both accepted and rejected) from the specified neighbor.
routes	(Optional) Displays all routes that are received and accepted. This is a subset of the output from the received-routes keyword.
advertised-routes	(Optional) Displays all the routes the router has advertised to the neighbor.
paths regexp	(Optional) Regular expression that is used to match the paths received.
dampened-routes	(Optional) Displays the dampened routes to the neighbor at the IP address specified.

Command Modes

Privileged EXEC

Command History

Release	Modification
10.0	This command was introduced.
11.2	The received-routes keyword was added.
12.0(21)ST	This command was updated to display MPLS label information.

Examples

The following is sample output from the show ip bgp neighbors command in privileged EXEC mode. The lines of output in bold show that Multliprotocol Label Switching (MPLS) labels are being sent and received.

Router# show ip bgp neighbors 172.16.232.178

BGP neighbor is 172.16.232.178,  remote AS 35, external link

  BGP version 4, remote router ID 192.168.3.3

  BGP state = Established, up for 1w1d

  Last read 00:00:53, hold time is 180, keepalive interval is 60 seconds

  Neighbor capabilities:

MPLS Label capability:  advertised and received

Address family IPv4 Unicast: advertised and received

Address family IPv4 Multicast: advertised and received

  Received 12519 messages, 0 notifications, 0 in queue

  Sent 12523 messages, 0 notifications, 0 in queue

  Route refresh request: received 0, sent 0

  Minimum time between advertisement runs is 30 seconds

 For address family: IPv4 Unicast

  BGP table version 5, neighbor version 5

  Index 1, Offset 0, Mask 0x2

  Community attribute sent to this neighbor

Inbound path policy configured

  Outbound path policy configured

  Route map for incoming advertisements is uni-in

  Route map for outgoing advertisements is uni-out

  Sending Prefix & Label

  3 accepted prefixes consume 108 bytes

  Prefix advertised 6, suppressed 0, withdrawn 0 

 For address family: IPv4 Multicast

  BGP table version 5, neighbor version 5

  Index 1, Offset 0, Mask 0x2

  Inbound path policy configured

  Outbound path policy configured

  Route map for incoming advertisements is mul-in

  Route map for outgoing advertisements is mul-out

  3 accepted prefixes consume 108 bytes

  Prefix advertised 6, suppressed 0, withdrawn 0

  Connections established 2; dropped 1

  Last reset 1w1d, due to Peer closed the session     

Connection state is ESTAB, I/O status: 1, unread input bytes: 0

Local host: 172.16.232.178, Local port: 179

Foreign host: 172.16.232.179, Foreign port: 11002

Enqueued packets for retransmit: 0, input: 0  mis-ordered: 0 (0 bytes)

Event Timers (current time is 0x2CF49CF8):

Timer          Starts    Wakeups            Next

Retrans         12518          0             0x0

TimeWait            0          0             0x0

AckHold         12514      12281             0x0

SendWnd             0          0             0x0

KeepAlive           0          0             0x0

GiveUp              0          0             0x0

PmtuAger            0          0             0x0

DeadWait            0          0             0x0

iss:  273358651  snduna:  273596614  sndnxt:  273596614     sndwnd:  15434

irs:  190480283  rcvnxt:  190718186  rcvwnd:      15491  delrcvwnd:    893

SRTT: 300 ms, RTTO: 607 ms, RTV: 3 ms, KRTT: 0 ms

minRTT: 0 ms, maxRTT: 300 ms, ACK hold: 200 ms

Flags: passive open, nagle, gen tcbs         

Datagrams (max data segment is 1460 bytes):

Rcvd: 24889 (out of order: 0), with data: 12515, total data bytes: 237921

Sent: 24963 (retransmit: 0), with data: 12518, total data bytes: 237981      

Table 3 describes the significant fields shown in the display.

Table 3 show ip bgp neighbors Field Descriptions 

Field	Description
BGP neighbor	IP address of the BGP neighbor and its autonomous system number. If the neighbor is in the same autonomous system as the router, then the link between them is internal; otherwise, it is considered external.
remote AS	Autonomous system of the neighbor.
external link	Indicates that this peer is an EBGP peer.
BGP version	BGP version being used to communicate with the remote router; the router ID (an IP address) of the neighbor is also specified.
remote router ID	IP address of the neighbor.
BGP state	Internal state of this BGP connection.
up for	Amount of time that the underlying TCP connection has been in existence.
Last read	Time that BGP last read a message from this neighbor.
hold time	Maximum amount of time that can elapse between messages from the peer.
keepalive interval	Time period between sending keepalive packets, which help ensure that the TCP connection is up.
Neighbor capabilities	BGP capabilities advertised and received from this neighbor.
MPLS Label capability	Indicates that MPLS labels are both sent and received by the EBGP peer.
Address family IPv4 Unicast:	IP Version 4 unicast-specific properties of this neighbor.
Address family IPv4 Multicast:	IP Version 4 multicast-specific properties of this neighbor.
Received	Number of total BGP messages received from this peer, including keepalives.
notifications	Number of error messages received from the peer.
Sent	Total number of BGP messages that have been sent to this peer, including keepalives.
notifications	Number of error messages the router has sent to this peer.
Route refresh request:	Number of route refresh requests sent and received from this neighbor.
advertisement runs	Value of minimum advertisement interval.
For address family:	Address family to which the following fields refer.
BGP table version	Indicates that the neighbor has been updated with this version of the primary BGP routing table.
neighbor version	Number used by the software to track the prefixes that have been sent and those that must be sent to this neighbor.
Community attribute	Appears if the neighbor send-community command is configured for this neighbor.
Inbound path policy	Indicates if an inbound policy is configured.
Outbound path policy	Indicates if an outbound policy is configured.
uni-in	Name of inbound route map for the unicast address family.
uni-out	Name of outbound route map for the unicast address family.
mul-in	Name of inbound route map for the multicast address family.
mul-out	Name of outbound route map for the multicast address family.
Sending Prefix & Label	Indicates that the EBGP peer sends MPLS labels with its routes.
accepted prefixes	Number of prefixes accepted.
Prefix advertised	Number of prefixes advertised.
suppressed	Number of prefixes suppressed.
withdrawn	Number of prefixes withdrawn.
Connections established	Number of times the router has established a TCP connection and the two peers have agreed to speak BGP with each other.
dropped	Number of times that a good connection has failed or been taken down.
Last reset	Elapsed time since this peering session was last reset.
Connection state	State of BGP peer.
unread input bytes	Number of bytes of packets still to be processed.
Local host, Local port	Peering address of local router, plus port.
Foreign host, Foreign port	Peering address of the neighbor.
Event Timers	Table displays the number of starts and wakeups for each timer.
iss	Initial send sequence number.
snduna	Last send sequence number the local host sent but has not received an acknowledgment for.
sndnxt	Sequence number the local host will send next.
sndwnd	TCP window size of the remote host.
irs	Initial receive sequence number.
rcvnxt	Last receive sequence number the local host has acknowledged.
rcvwnd	TCP window size of the local host.
delrcvwnd	Delayed receive window—data the local host has read from the connection, but has not yet subtracted from the receive window the host has advertised to the remote host. The value in this field gradually increases until it is larger than a full-sized packet, at which point it is applied to the rcvwnd field.
SRTT	A calculated smoothed round-trip timeout.
RTTO	Round-trip timeout.
RTV	Variance of the round-trip time.
KRTT	New round-trip timeout (using the Karn algorithm). This field separately tracks the round-trip time of packets that have been re-sent.
minRTT	Smallest recorded round-trip timeout (hard wire value used for calculation).
maxRTT	Largest recorded round-trip timeout.
ACK hold	Time the local host will delay an acknowledgment in order to piggyback data on it.
Flags	IP precedence of the BGP packets.
Datagrams: Rcvd	Number of update packets received from a neighbor.
with data	Number of update packets received with data.
total data bytes	Total bytes of data.
Sent	Number of update packets sent.
with data	Number of update packets with data sent.
total data bytes	Total number of data bytes.

The following is sample output from the show ip bgp neighbors command with the advertised-routes keyword in privileged EXEC mode:

Router# show ip bgp neighbors 172.16.232.178 advertised-routes

BGP table version is 27, local router ID is 172.16.232.181

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop          Metric LocPrf Weight Path

*>i110.0.0.0        172.16.232.179         0    100      0 ?

*> 200.2.2.0        0.0.0.0                0         32768 i

The following is sample output from the show ip bgp neighbors command with the routes keyword in privileged EXEC mode:

Router# show ip bgp neighbors 172.16.232.178 routes

BGP table version is 27, local router ID is 172.16.232.181

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop          Metric LocPrf Weight Path

*> 10.0.0.0         172.16.232.178        40             0 10 ?

*> 20.0.0.0         172.16.232.178        40             0 10 ?

Table 4 describes the significant fields shown in the displays.

Table 4 show ip bgp neighbors advertised-routes and routes Field Descriptions 

Field	Description
BGP table version	Internal version number of the table. This number increments when the table changes.
local router ID	IP address of the router.
Status codes	Status of the table entry. The status is displayed at the beginning of each line in the table. It can be one of the following values: s—The table entry is suppressed. d—The table entry is dampened and will not be advertised to BGP neighbors. h—The table entry does not contain the best path based on historical information. *—The table entry is valid. >—The table entry is the best entry to use for that network. i—The table entry was learned via an Internal BGP (IBGP) session.
Origin codes	Origin of the entry. The origin code is placed at the end of each line in the table. It can be one of the following values: i—Entry originated from Interior Gateway Protocol (IGP) and was advertised with a network router configuration command. e—Entry originated from Exterior Gateway Protocol (EGP). ?—Origin of the path is not clear. Usually, this is a router that is redistributed into BGP from an IGP.
Network	IP address of a network entity.
Next Hop	IP address of the next system that is used when forwarding a packet to the destination network. An entry of 0.0.0.0 indicates that the router has some non-BGP routes to this network.
Metric	If shown, this is the value of the inter-autonomous system metric. This field is frequently not used.
LocPrf	Local preference value as set with the set local-preference route-map configuration command. The default value is 100.
Weight	Weight of the route as set via autonomous system filters.
Path	Autonomous system paths to the destination network. There can be one entry in this field for each autonomous system in the path.

The following is sample output from the show ip bgp neighbors command with the paths keyword in privileged EXEC mode:

Router# show ip bgp neighbors 171.69.232.178 paths ^10

Address    Refcount Metric Path

0x60E577B0        2     40 10 ?

Table 5 describes the significant fields shown in the display.

Table 5 show ip bgp neighbors paths Field Descriptions

Field	Description
Address	Internal address where the path is stored.
Refcount	Number of routes using that path.
Metric	The Multi Exit Discriminator (MED) metric for the path. (The name of this metric for BGP versions 2 and 3 is INTER_AS.)
Path	The autonomous system path for that route, followed by the origin code for that route.

show ip bgp vpnv4

To display Virtual Private Network (VPN) address information from the Border Gateway Protocol (BGP) table, use the show ip bgp vpnv4 command in EXEC mode.

show ip bgp vpnv4 {all | rd route-distinguisher | vrf vrf-name} [ip-prefix/length [longer-prefixes] [output-modifiers]] [network-address [mask] [longer-prefixes] [output-modifiers]] [cidr-only] [community] [community-list] [dampened-paths] [filter-list] [flap-statistics] [inconsistent-as] [neighbors] [paths [line]] [peer-group] [quote-regexp] [regexp] [summary] [labels]

Syntax Description

all	Displays the complete VPNv4 database.
rd route-distinguisher	Displays NLRIs that have a matching route distinguisher.
vrf vrf-name	Displays NLRIs associated with the named VRF.
ip-prefix/length	(Optional) The IP prefix address (in dotted decimal format) and the length of the mask (0 to 32).
longer-prefixes	(Optional) Displays the entry, if any, that exactly matches the specified prefix parameter and all entries that match the prefix in a "longest-match" sense. That is, prefixes for which the specified prefix is an initial substring.
output-modifiers	(Optional) For a list of associated keywords and arguments, use context-sensitive help.
network-address	(Optional) The IP address of a network in the BGP routing table.
mask	(Optional) The mask of the network address, in dotted decimal format.
cidr-only	(Optional) Displays only routes that have nonnatural net masks.
community	(Optional) Displays routes matching this community.
community-list	(Optional) Displays routes matching this community list.
dampened-paths	(Optional) Displays paths suppressed on account of dampening (BGP route from peer is up and down).
filter-list	(Optional) Displays routes conforming to the filter list.
flap-statistics	(Optional) Displays flap statistics of routes.
inconsistent-as	(Optional) Displays only routes that have inconsistent autonomous systems of origin.
neighbors	(Optional) Displays details about TCP and BGP neighbor connections.
paths	(Optional) Displays path information.
line	(Optional) A regular expression to match the BGP autonomous system paths.
peer-group	(Optional) Displays information about peer groups.
quote-regexp	(Optional) Displays routes matching the autonomous system path "regular expression."
regexp	(Optional) Displays routes matching the autonomous system path regular expression.
summary	(Optional) Displays BGP neighbor status.
labels	(Optional) Displays incoming and outgoing BGP labels for each NLRI.

Defaults

This command has no default behavior or values.

Command Modes

EXEC

Command History

Release	Modification
12.0(5)T	This command was introduced.
12.2(2)T	The output of the show ip bgp vpnv4 all ip-prefix command was enhanced to display attributes including multipaths and a best path to the specified network.
12.0(21)ST	The keyword tags was replaced with the keyword labels to conform to the MPLS IETF guidelines.

Usage Guidelines

Use this command to display VPNv4 information from the BGP database. The show ip bgp vpnv4 all command displays all available VPNv4 information. The show ip bgp vpnv4 summary command displays BGP neighbor status.

Examples

The following example shows output for all available VPNv4 information in a BGP routing table:

Router# show ip bgp vpnv4 all

BGP table version is 18, local router ID is 14.14.14.14

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP,? - incomplete

   Network          Next Hop 	Metric LocPrf 	Weight 	Path

Route Distinguisher: 100:1 (vrf1)

*> 11.0.0.0         50.0.0.1 		0 	0 	101 i

*>i12.0.0.0         13.13.13.13 		0    100 	0 	102 i

*> 50.0.0.0         50.0.0.1 	0 	0 	101 i

*>i51.0.0.0         13.13.13.13 	0    100 	0 	102 i

Table 6 describes the significant fields shown in the display.

Table 6 show ip bgp vpnv4 Field Descriptions

Field	Description
Network	Displays the network address from the BGP table.
Next Hop	Displays the address of the BGP next hop.
Metric	Displays the BGP metric.
LocPrf	Displays the local preference.
Weight	Displays the BGP weight.
Path	Displays the BGP path per route.

The following example shows how to display a table of labels for NLRIs that have a route distinguisher value of 100:1.

Router# show ip bgp vpnv4 rd 100:1 labels

	Network			Next Hop      In label/Out label

Route Distinguisher: 100:1 (vrf1)

   2.0.0.0          10.20.0.60      34/nolabel

   10.0.0.0         10.20.0.60      35/nolabel

   12.0.0.0         10.20.0.60      26/nolabel

                    10.20.0.60      26/nolabel

   13.0.0.0         10.15.0.15      nolabel/26

Table 7 describes the significant fields shown in the display.

Table 7 show ip bgp vpnv4 rd labels Field Descriptions

Field	Description
Network	Displays the network address from the BGP table.
Next Hop	Specifies the BGP next hop address.
In	Displays the label (if any) assigned by this router.
Out	Displays the label assigned by the BGP next hop router.

The following example shows VPNv4 routing entries for the VRF named vrf1:

Router# show ip bgp vpnv4 vrf vrf1

BGP table version is 18, local router ID is 14.14.14.14

Status codes: s suppressed, d damped, h history, * valid, > best, i - internal

Origin codes: i - IGP, e - EGP,? - incomplete

Network          Next Hop 	Metric LocPrf 	Weight 	Path

Route Distinguisher: 100:1 (vrf1)

*> 11.0.0.0         50.0.0.1 		0 	0 	101 i

*>i12.0.0.0         13.13.13.13 		0    100 	0 	102 i

*> 50.0.0.0         50.0.0.1 	0 	0 	101 i

*>i51.0.0.0         13.13.13.13 	0    100 	0 	102 i

Table 8 describes the significant fields shown in the display.

Table 8 show ip bgp vpnv4 vrf Field Descriptions

Field	Description
Network	Displays the network address from the BGP table.
Next Hop	Displays the address of the BGP next hop.
Metric	Displays the BGP metric.
LocPrf	Displays the local preference.
Weight	Displays the BGP weight.
Path	Displays the BGP path per route.

The following example shows attributes for network 10.22.22.0 that includes multipaths and a best path:

Router# show ip bgp vpnv4 all 10.22.22.0

BGP routing table entry for 100:1:10.22.22.0/24, version 50

Paths:(6 available, best #1)

Multipath:iBGP

  Advertised to non peer-group peers:

  200.1.12.12 

  22

    1.22.7.8 (metric 11) from 1.11.3.4 (100.0.0.8)

      Origin IGP, metric 0, localpref 100, valid, internal, multipath, best

      Extended Community:RT:100:1

      Originator:100.0.0.8, Cluster list:100.1.1.44

  22

    1.22.1.9 (metric 11) from 1.11.1.2 (100.0.0.9)

      Origin IGP, metric 0, localpref 100, valid, internal, multipath

      Extended Community:RT:100:1

      Originator:100.0.0.9, Cluster list:100.1.1.22

  22

    1.22.6.10 (metric 11) from 1.11.6.7 (100.0.0.10)

      Origin IGP, metric 0, localpref 100, valid, internal, multipath

      Extended Community:RT:100:1

      Originator:100.0.0.10, Cluster list:100.0.0.7

  22

    1.22.4.10 (metric 11) from 1.11.4.5 (100.0.0.10)

      Origin IGP, metric 0, localpref 100, valid, internal, multipath

      Extended Community:RT:100:1

      Originator:100.0.0.10, Cluster list:100.0.0.5

  22

    1.22.5.10 (metric 11) from 1.11.5.6 (100.0.0.10)

      Origin IGP, metric 0, localpref 100, valid, internal, multipath

      Extended Community:RT:100:1

      Originator:100.0.0.10, Cluster list:100.0.0.6

Table 9 describes the significant fields shown in the display.

Table 9 show ip bgp vpn4 all 10.22.22.0 Field Descriptions 

Field	Description
BGP routing table ... version	Internal version number of the table. This number is incremented whenever the table changes.
Paths:	Number of autonomous system paths to the specified network. If multiple paths exist, one of the multipaths is designated the best path.
Multipath:	Indicates the maximum-paths configured (IBGP or EBGP).
Advertised to non peer-group peers: 200.1.12.12 22	IP address of the BGP peers that the specified route is advertised to.
1.22.7.8 (metric 11) from 1.11.3.4 (100.0.0.8)	Indicates the next hop address and the address of the gateway that sent the update.
Origin	Indicates the origin of the entry. It can be one of the following values: IGP—Entry originated from Interior Gateway Protocol (IGP) and was advertised with a network router configuration command. incomplete — Entry originated from other than an IGP or Exterior Gateway Protocol (EGP) and was advertised with the redistribute router configuration command. EGP — Entry originated from an EGP.
metric	If shown, the value of the interautonomous system metric.
localpref	Local preference value as set with the set local-preference route-map configuration command. The default value is 100.
valid	Indicates that the route is usable and has a valid set of attributes.
internal/external	The field is internal if the path is learned via IBGP. The field is external if the path is learned via EBGP.
multipath	One of multiple paths to the specified network.
best	If multiple paths exist, one of the multipaths is designated the best path and advertised the neighbors.
Extended Community:RT:100:1	Route Target value associated with the specified route.
Originator:	The router ID of the route originating router when route reflector is used.
Cluster list:	The router ID of all the route reflectors that the specified route has passed through.

Related Commands

Command	Description
show ip vrf	Displays the set of defined VRFs and associated interfaces.

show route-map

To display all route maps configured or only the one specified, use the show route-map command in EXEC mode.

show route-map [map-name]

Syntax Description

map-name

(Optional) Name of a specific route map.

Command Modes

EXEC

Command History

Release	Modification
10.0	This command was introduced.
12.0(21)ST	This command was updated to display information about MPLS labels.

Examples

The following is sample output from the show route-map command:

Router# show route-map

route-map sid, permit, sequence 10

Match clauses:

    tag 1 2

Set clauses:

    metric 5

route-map sid, permit, sequence 20

Match clauses:

    tag 3 4

Set clauses:

    metric 6

The following example shows MPLS-related route map information:

Router# show route-map

route-map OUT, permit, sequence 10

Match clauses:

  ip address (access-lists): 1 

Set clauses:

  mpls label

Policy routing matches: 0 packets, 0 bytes

route-map IN, permit, sequence 10

Match clauses:

  ip address (access-lists): 2 

  mpls label

Set clauses:

Policy routing matches: 0 packets, 0 bytes

Table 10 describes the fields shown in the display

.

Table 10 Show route-map Field Descriptions

Field	Description
route-map	Name of the route map.
permit	Indicates that the route is redistributed as controlled by the set actions.
sequence	The position a route map takes in the list of route maps already configured with the same name.
Match clauses:	Match criteria—conditions under which redistribution is allowed for the current route map.
Set clauses:	Set actions—the particular redistribution actions to perform if the criteria enforced by the match commands are met.

Related Commands

Command	Description
redistribute (ISO CLNS)	Redistributes routing information from one domain into another routing domain.
route-map (ISO CLNS)	Defines the conditions for redistributing routes from one routing protocol into another.

Glossary

ASBR—Autonomous system border router.

autonomous system (AS) — A collection of networks that share the same routing protocol and that are under the same system administration.

Border Gateway Protocol (BGP)—The exterior border gateway protocol used to exchange routing information between routers in separate autonomous systems. BGP uses Transmission Control Protocol (TCP). Because TCP is a reliable protocol, BGP does not experience problems with dropped or fragmented data packets.

customer edge (CE) router—The customer router that connects to the provider edge (PE) router.

External Border Gateway Protocol (EBGP)—A BGP session between routers in different autonomous systems. When a pair of routers in different ASs are more than one IP hop away from each other, an External BGP session between those two routers is called multihop External BGP.

Internal Border Gateway Protocol (IBGP)—A BGP session between routers within the same autonomous system.

label edge router (LER)—The edge router that performs label imposition and disposition.

Network Layer Reachability Information (NLRI)— BGP sends routing update messages containing NLRI, which describes the route. In this context, an NLRI is a prefix. A BGP update message carries one or more NLRI prefixes and the attributes of a route for the NLRI prefixes. The route attributes include a BGP next hop gateway address, community values, and other information.

provider edge (PE) router—The label edge router (LER) in the service provider network that connects to the customer edge (CE) router.

route reflector—A router that advertises, or reflects, IBGP learned routes to other IBGP peers without requiring a full network mesh.

Virtual Private Network (VPN)—A group of sites that, as a result of a set of administrative policies, can communicate with each other over a shared backbone.

VPNv4 addresses—When multiple VPNs use the same address space, the VPN addresses are made unique by adding a route distinguisher to the front of the address.