MP-IBGP Configuration Example 175
Route Distinguisher in MP-BGP
The route distinguisher value is prepended to customer routes carried in MP-BGP. To get more information about what routes have what route distinguisher values, use the show ip bgp vpnv4 all command. A sample output is as follows:
Atlanta#show ip bgp vpnv4 all
BGP table version is 21, local router ID is 204.134.83.1
.
.output omitted
.
Network |
Next Hop |
Metric LocPrf Weight Path |
Route Distinguisher: 65000:1 (default for vrf vpn_1)
*> |
192.168.1.1/32 |
192.168.3.5 |
782 |
|
32768 |
? |
*>i192.168.2.1/32 |
204.134.83.3 |
782 |
100 |
0 |
? |
|
*> |
192.168.3.4/30 |
0.0.0.0 |
0 |
|
32768 |
? |
*>i192.168.3.8/30 |
204.134.83.3 |
0 |
100 |
0 |
? |
|
Notice in the output that a route distinguisher of 65000:1 is being used. In the real world, you probably won’t want to see all the route distinguishers, only a particular one for a single VRF. To view only the routes prepended with a single route target, use the show ip bgp vpnv4 rd route-target-value command. You can find more information about these commands and their uses at www.cisco.com.
MP-IBGP Configuration Example
This section revisits the simple network you saw in Chapter 2, “FrameMode MPLS.” In this example, you’ll be configuring and verifying MP-BGP in preparation for configuring VPNs in Chapter 6.
Figure 5.10 contains a simple service provider network.
F I G U R E 5 . 1 0 A simple service provider network
Serial |
0 |
Serial |
0/1 |
Serial |
0/0 |
Serial |
0/1 |
Serial |
0/0 |
Serial |
0/3 |
Serial |
0/1 |
Serial |
0 |
|
|
|
|
|
|
|
|
||||||||
Peer 1 |
|
Atlanta |
|
|
|
Core |
|
|
Raleigh |
|
|
|
Peer 2 |
||
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176 Chapter 5 MPLS VPNs
Table 5.7 lists the IP addresses and interfaces of all the service provider devices in Figure 5.10.
T A B L E |
5 . 7 Service Provider IP Addressing |
|
|
|
|
|
|
|
|
Device |
Loopback 0 |
Serial 0/0 |
Serial 0/1 |
Serial 0/3 |
|
|
|
|
|
Atlanta |
204.134.83.1/32 |
204.134.83.5/30 |
192.168.3.6/30 |
N/A |
Core |
204.134.83.2/32 |
204.134.83.9/30 |
204.134.83.6/30 |
N/A |
Raleigh |
204.134.83.3/32 |
N/A |
192.168.3.9/30 |
204.134.83.10/30 |
|
|
|
|
|
Table 5.8 lists the IP addresses of the peer devices in Figure 5.10.
T A B L E 5 . 8 PE Customer Link Addressing
Device |
Loopback 0 |
Serial 0 |
|
|
|
Peer 1 |
192.168.1.1/32 |
192.168.3.5/30 |
Peer 2 |
192.168.2.1/32 |
192.168.3.10/30 |
|
|
|
Initial Network Configuration
In the example in Figure 5.10, the network is already configured with an IGP, BGP, and tag switching. The IGP runs on the Atlanta, Core, and Raleigh routers. Tag switching has been enabled on the internal links for the Atlanta, Core, and Raleigh routers. BGP has been configured between the Atlanta and Raleigh routers.
Device Configuration
The configuration of the Atlanta POP router is as follows:
Atlanta#show running-config
Building configuration...
Current configuration : 1492 bytes
!
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MP-IBGP Configuration Example 177
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Atlanta
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.1 255.255.255.255
!
interface Serial0/0
description *** Link to Core Router ***
ip address 204.134.83.5 255.255.255.252 tag-switching ip
no fair-queue clockrate 64000
!
interface Serial0/1
description *** Link to Peer1 ***
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178 Chapter 5 MPLS VPNs
no ip address shutdown clockrate 64000
!
interface Serial0/2 no ip address shutdown
clockrate 64000
!
interface Serial0/3 no ip address shutdown
clockrate 64000
!
interface Ethernet1/0 no ip address shutdown
!
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router rip version 2
network 204.134.83.0
!
router bgp 65000
no synchronization
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MP-IBGP Configuration Example 179
bgp log-neighbor-changes
neighbor 204.134.83.3 remote-as 65000 neighbor 204.134.83.3 update-source Loopback0 neighbor 204.134.83.3 next-hop-self
no auto-summary
!
ip classless
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
The configuration of the Core router is as follows:
Core#show running-config
Building configuration...
Current configuration : 1249 bytes
!
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
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180 Chapter 5 MPLS VPNs
!
hostname Core
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.2 255.255.255.255
!
interface Serial0/0
description *** Connection to Raleigh POP ***
ip address 204.134.83.9 255.255.255.252 tag-switching ip
no fair-queue
!
interface Serial0/1
description *** Connection to Atlanta POP ***
ip address 204.134.83.6 255.255.255.252 tag-switching ip
!
interface Serial0/2
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MP-IBGP Configuration Example 181
no ip address shutdown
!
interface Serial0/3 no ip address shutdown
!
interface Ethernet1/0 no ip address shutdown
!
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router rip version 2
network 204.134.83.0
!
ip classless
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous
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182 Chapter 5 MPLS VPNs
transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15 password cisco logging synchronous login
ip netmask-format decimal
!
end
The configuration of the Raleigh POP router is as follows:
Raleigh#show running-config
Building configuration...
Current configuration : 1531 bytes
!
version 12.1
service timestamps debug uptime service timestamps log uptime no service password-encryption
!
hostname Raleigh
!
enable password cisco
!
!
!
!
!
memory-size iomem 25 ip subnet-zero
ip tcp synwait-time 5 no ip domain-lookup
!
ip cef
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MP-IBGP Configuration Example 183
cns event-service server
!
!
!
!
!
interface Loopback0
ip address 204.134.83.3 255.255.255.255
!
interface Serial0/0 no ip address shutdown
no fair-queue clockrate 64000
!
interface Serial0/1
description *** Link to Peer2 ***
no ip address shutdown clockrate 64000
!
interface Serial0/2 no ip address shutdown
clockrate 64000
!
interface Serial0/3
description *** Link to Core Router ***
ip address 204.134.83.10 255.255.255.252 tag-switching ip
clockrate 64000
!
interface Ethernet1/0 no ip address shutdown
!
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184 Chapter 5 MPLS VPNs
interface Ethernet1/1 no ip address shutdown
!
interface Ethernet1/2 no ip address shutdown
!
interface Ethernet1/3 no ip address shutdown
!
router rip version 2
network 204.134.83.0
!
router bgp 65000
no synchronization
bgp log-neighbor-changes
neighbor 204.134.83.1 remote-as 65000 neighbor 204.134.83.1 update-source Loopback0 neighbor 204.134.83.1 next-hop-self
no auto-summary
!
ip classless
no ip http server
!
!
!
line con 0 exec-timeout 0 0 privilege level 15 logging synchronous transport input none
ip netmask-format decimal line aux 0
line vty 0 4 privilege level 15
Copyright ©2002 SYBEX, Inc., Alameda, CA |
www.sybex.com |