- Cisco BGP Overview
- Configuring a Basic BGP Network
- Connecting to a Service Provider Using External BGP
- Configuring BGP Neighbor Session Options
- Configuring Internal BGP Features
- Configuring Advanced BGP Features
- BGP Link Bandwidth
- iBGP Multipath Load Sharing
- BGP Multipath Load Sharing for Both eBGP and iBGP in an MPLS-VPN
- Loadsharing IP Packets Over More Than Six Parallel Paths
- BGP Policy Accounting
- BGP Policy Accounting Output Interface Accounting
- BGP Cost Community
- BGP Support for IP Prefix Import from Global Table into a VRF Table
- Per-VRF Assignment of BGP Router ID
- BGP Next Hop Unchanged
- Finding Feature Information
- Prerequisites for Per-VRF Assignment of BGP Router ID
- Information About Per-VRF Assignment of BGP Router ID
- How to Configure Per-VRF Assignment of BGP Router ID
- Configuration Examples for Per-VRF Assignment of BGP Router ID
- Additional References
- Command Reference
- Feature Information for Per-VRF Assignment of BGP Router ID
Per-VRF Assignment of BGP Router ID
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
- Finding Feature Information
- Prerequisites for Per-VRF Assignment of BGP Router ID
- Information About Per-VRF Assignment of BGP Router ID
- How to Configure Per-VRF Assignment of BGP Router ID
- Configuration Examples for Per-VRF Assignment of BGP Router ID
- Additional References
- Command Reference
- Feature Information for Per-VRF Assignment of BGP Router ID
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Per-VRF Assignment of BGP Router ID
Before you configure this feature, Cisco Express Forwarding (CEF) or distributed CEF (dCEF) must be enabled in the network, and basic BGP peering is assumed to be running in the network.
Information About Per-VRF Assignment of BGP Router ID
BGP Router ID
The BGP router identifier (ID) is a 4-byte field that is set to the highest IP address on the router. Loopback interface addresses are considered before physical interface addresses because loopback interfaces are more stable than physical interfaces. The BGP router ID is used in the BGP algorithm for determining the best path to a destination where the preference is for the BGP router with the lowest router ID. It is possible to manually configure the BGP router ID using the bgp router-id command to influence the best path algorithm.
Per-VRF Router ID Assignment
In Cisco IOS Release 12.2(31)SB2, 12.2(33)SRA, 12.2(33)SXH, 12.4(20)T, and later releases, support for configuring separate router IDs for each Virtual Private Network (VPN) routing/forwarding (VRF) instance was introduced. The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF.
Route Distinguisher
A route distinguisher (RD) creates routing and forwarding tables and specifies the default route distinguisher for a VPN. The RD is added to the beginning of an IPv4 prefix to change it into a globally unique VPN-IPv4 prefix. An RD can be composed in one of two ways: with an autonomous system number and an arbitrary number or with an IP address and an arbitrary number.
You can enter an RD in either of these formats:
- Enter a 16-bit autonomous system number, a colon, and a 32-bit number. For example:
45000:3
- Enter a 32-bit IP address, a colon, and a 16-bit number. For example:
192.168.10.15:1
How to Configure Per-VRF Assignment of BGP Router ID
There are two main ways to configure a BGP router ID for each separate VRF. To configure a per-VRF BGP router ID manually, you must perform the first three tasks listed below. To automatically assign a BGP router ID to each VRF, perform the first task and the fourth task.
- Configuring VRF Instances
- Associating VRF Instances with Interfaces
- Manually Configuring a BGP Router ID per VRF
- Automatically Assigning a BGP Router ID per VRF
Configuring VRF Instances
Perform this task to configure VRF instances to be used with the per-VRF assignment tasks. In this task, a VRF instance named vrf_trans is created. To make the VRF functional, a route distinguisher is created. When the route distinguisher is created, the routing and forwarding tables are created for the VRF instance named vrf_trans.
This task assumes that you have CEF or dCEF enabled.
DETAILED STEPS
Associating VRF Instances with Interfaces
Perform this task to associate VRF instances with interfaces to be used with the per-VRF assignment tasks. In this task, a VRF instance named vrf_trans is associated with a serial interface.
Make a note of the IP addresses for any interface to which you want to associate a VRF instance because the ip vrf forwarding command removes the IP address. Step 8 allows you to reconfigure the IP address.
- This task assumes that you have CEF or dCEF enabled.
- This task assumes that VRF instances have been configured in the Configuring VRF Instances.
DETAILED STEPS
Examples
The following output show s that two VRF instances named vrf_trans and vrf_users were configured on two serial interfaces.
Router# show ip vrf interfaces
Interface IP-Address VRF Protocol
Serial2 192.168.4.1 vrf_trans up
Serial3 192.168.5.1 vrf_user up
Manually Configuring a BGP Router ID per VRF
Perform this task to manually configure a BGP router ID for each VRF. In this task, several address family configurations are shown and the router ID is configured in the IPv4 address family mode for one VRF instance. Step 22 shows you how to repeat certain steps to permit the configuration of more than one VRF on the same router.
This task assumes that you have previously created the VRF instances and associated them with interfaces. For more details, see the Configuring VRF Instances and the Associating VRF Instances with Interfaces.
DETAILED STEPS
Command or Action | Purpose | |||
---|---|---|---|---|
|
Example: Router> enable |
Enables privileged EXEC mode. |
||
|
Example: Router# configure terminal |
Enters global configuration mode. |
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Example: Router(config)# router bgp 45000 |
Enters router configuration mode for the specified routing process. |
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Example: Router(config-router)# no bgp default ipv4-unicast |
Disables the IPv4 unicast address family for the BGP routing process.
|
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Example: Router(config-router)# bgp log-neighbor-changes |
Enables logging of BGP neighbor resets. |
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|
Example: Router(config-router)# neighbor 192.168.1.1 remote-as 45000 |
Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.
|
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Example: Router(config-router)# neighbor 192.168.1.1 update-source loopback0 |
Allows BGP sessions to use any operational interface for TCP connections. |
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Example: Router(config-router)# address-family vpnv4 |
Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations. |
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Example: Router(config-router-af)# neighbor 172.16.1.1 activate |
Activates the neighbor under the VPNv4 address family. |
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Example: Router(config-router-af)# neighbor 172.16.1.1 send-community extended |
Specifies that a communities attribute should be sent to a BGP neighbor. |
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Example: Router(config-router-af)# exit-address-family |
Exits address family configuration mode and returns to router configuration mode. |
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Example: Router(config-router)# address-family ipv4 vrf vrf_trans |
Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations. |
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Example: Router(config-router-af)# redistribute connected |
Redistributes from one routing domain into another routing domain. |
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Example: Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000 |
Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.
|
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Example: Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend |
Customizes the AS_PATH attribute for routes received from an eBGP neighbor.
|
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Example: Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2 |
Accepts and attempts BGP connections to external peers residing on networks that are not directly connected. |
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Example: Router(config-router-af)# neighbor 192.168.1.1 activate |
Activates the neighbor under the IPV4 address family. |
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Example: Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1 |
Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers. |
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Example: Router(config-router-af)# no auto-summary |
Disables automatic summarization and sends subprefix routing information across classful network boundaries. |
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Example: Router(config-router-af)# no synchronization |
Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP). |
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Example: Router(config-router-af)# bgp router-id 10.99.1.1 |
Configures a fixed router ID for the local BGP routing process. |
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-- |
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Example: Router(config-router-af)# end |
Exits address family configuration mode and returns to privileged EXEC mode. |
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Example: Router# show ip bgp vpnv4 all |
(Optional) Displays VPN address information from the BGP table.
|
Examples
The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured each with a separate router ID. The router ID is shown next to the VRF name.
Router# show ip bgp vpnv4 all
BGP table version is 5, local router ID is 172.17.1.99
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 192.168.4.0 0.0.0.0 0 32768 ?
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
*> 192.168.5.0 0.0.0.0 0 32768 ?
Automatically Assigning a BGP Router ID per VRF
Perform this task to automatically assign a BGP router ID for each VRF. In this task, a loopback interface is associated with a VRF and the bgp router-id command is configured at the router configuration level to automatically assign a BGP router ID to all VRF instances. Step 9 shows you how to repeat certain steps to configure each VRF that is to be associated with an interface. Step 30 shows you how to configure more than one VRF on the same router.
This task assumes that you have previously created the VRF instances. For more details, see the Configuring VRF Instances.
DETAILED STEPS
Command or Action | Purpose | |||
---|---|---|---|---|
|
Example: Router> enable |
Enables privileged EXEC mode. |
||
|
Example: Router# configure terminal |
Enters global configuration mode. |
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Example: Router(config)# interface loopback0 |
Configures an interface type and enters interface configuration mode. |
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Example: Router(config-if)# ip address 172.16.1.1 255.255.255.255 |
Configures an IP address. |
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Example: Router(config-if)# exit |
Exits interface configuration mode and returns to global configuration mode. |
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Example: Router(config)# interface loopback1 |
Configures an interface type and enters interface configuration mode. |
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Example: Router(config-if)# ip vrf forwarding vrf_trans |
Associates a VRF with an interface or subinterface.
|
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Example: Router(config-if)# ip address 10.99.1.1 255.255.255.255 |
Configures an IP address. |
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|
-- |
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Example: Router(config-if)# exit |
Exits interface configuration mode and returns to global configuration mode. |
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Example: Router(config)# router bgp 45000 |
Enters router configuration mode for the specified routing process. |
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Example: Router(config-router)# bgp router-id vrf auto-assign |
Configures a fixed router ID for the local BGP routing process. |
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Example: Router(config-router)# no bgp default ipv4-unicast |
Disables the IPv4 unicast address family for the BGP routing process.
|
||
|
Example: Router(config-router)# bgp log-neighbor-changes |
Enables logging of BGP neighbor resets. |
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|
Example: Router(config-router)# neighbor 192.168.1.1 remote-as 45000 |
Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.
|
||
|
Example: Router(config-router)# neighbor 192.168.1.1 update-source loopback0 |
Allows BGP sessions to use any operational interface for TCP connections. |
||
|
Example: Router(config-router)# address-family vpnv4 |
Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations. |
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Example: Router(config-router-af)# neighbor 172.16.1.1 activate |
Activates the neighbor under the VPNv4 address family. |
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|
Example: Router(config-router-af)# neighbor 172.16.1.1 send-community extended |
Specifies that a communities attribute should be sent to a BGP neighbor. |
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Example: Router(config-router-af)# exit-address-family |
Exits address family configuration mode and returns to router configuration mode. |
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Example: Router(config-router)# address-family ipv4 vrf vrf_trans |
Enters address family configuration mode to configure BGP peers to accept address-family-specific configurations. |
||
|
Example: Router(config-router-af)# redistribute connected |
Redistributes from one routing domain into another routing domain. |
||
|
Example: Router(config-router-af)# neighbor 192.168.1.1 remote-as 40000 |
Adds the IP address or peer group name of the neighbor in the specified autonomous system to the IPv4 multiprotocol BGP neighbor table of the local router.
|
||
|
Example: Router(config-router-af)# neighbor 192.168.1.1 local-as 50000 no-prepend |
Customizes the AS_PATH attribute for routes received from an eBGP neighbor.
|
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Example: Router(config-router-af)# neighbor 192.168.1.1 ebgp-multihop 2 |
Accepts and attempts BGP connections to external peers residing on networks that are not directly connected. |
||
|
Example: Router(config-router-af)# neighbor 192.168.1.1 activate |
Activates the neighbor under the IPV4 address family. |
||
|
Example: Router(config-router-af)# neighbor 192.168.1.1 allowas-in 1 |
Configures provider edge (PE) routers to allow the readvertisement of all prefixes that contain duplicate autonomous system numbers. |
||
|
Example: Router(config-router-af)# no auto-summary |
Disables automatic summarization and sends subprefix routing information across classful network boundaries. |
||
|
Example: Router(config-router-af)# no synchronization |
Enables the Cisco IOS software to advertise a network route without waiting for synchronization with an Internal Gateway Protocol (IGP). |
||
|
|
-- |
||
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Example: Router(config-router-af)# end |
Exits address family configuration mode and returns to privileged EXEC mode. |
||
|
Example: Router# show ip bgp vpnv4 all |
(Optional) Displays VPN address information from the BGP table.
|
Examples
The following sample output assumes that two VRF instances named vrf_trans and vrf_user were configured, each with a separate router ID. The router ID is shown next to the VRF name.
Router# show ip bgp vpnv4 all
BGP table version is 43, local router ID is 172.16.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 1:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0 0.0.0.0 0 32768 ?
r> 172.23.0.0 172.23.1.1 0 0 3 1 ?
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
*> 10.52.1.0/24 172.23.1.1 0 3 1 ?
*> 10.52.2.1/32 172.23.1.1 0 3 1 3 i
*> 10.52.3.1/32 172.23.1.1 0 3 1 3 i
*> 10.99.1.1/32 172.23.1.1 0 0 3 1 ?
*> 10.99.1.2/32 0.0.0.0 0 32768 ?
Route Distinguisher: 10:1
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
Route Distinguisher: 42:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0 172.22.1.1 0 0 2 1 ?
*> 172.23.0.0 0.0.0.0 0 32768 ?
*> 10.21.1.1/32 172.22.1.1 0 2 1 2 i
*>i10.52.1.0/24 192.168.3.1 0 100 0 ?
*>i10.52.2.1/32 192.168.3.1 0 100 0 3 i
*>i10.52.3.1/32 192.168.3.1 0 100 0 3 i
*> 10.99.1.1/32 0.0.0.0 0 32768 ?
*> 10.99.1.2/32 172.22.1.1 0 0 2 1 ?
Configuration Examples for Per-VRF Assignment of BGP Router ID
- Manually Configuring a BGP Router ID per VRF Examples
- Automatically Assigning a BGP Router ID per VRF Examples
Manually Configuring a BGP Router ID per VRF Examples
The following example shows how to configure two VRFs--vrf_trans and vrf_user--with sessions between each other on the same router. The BGP router ID for each VRF is configured manually under separate IPv4 address families. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF. The configuration starts in global configuration mode.
ip vrf vrf_trans rd 45000:1 route-target export 50000:50 route-target import 40000:1 ! ip vrf vrf_user rd 65500:1 route-target export 65500:1 route-target import 65500:1 ! interface Loopback0 ip address 10.1.1.1 255.255.255.255 ! interface Ethernet0/0 ip vrf forwarding vrf_trans ip address 172.22.1.1 255.255.0.0 ! interface Ethernet1/0 ip vrf forwarding vrf_user ip address 172.23.1.1 255.255.0.0 ! router bgp 45000 no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 192.168.3.1 remote-as 45000 neighbor 192.168.3.1 update-source Loopback0 ! address-family vpnv4 neighbor 192.168.3.1 activate neighbor 192.168.3.1 send-community extended exit-address-family ! address-family ipv4 vrf vrf_user redistribute connected neighbor 172.22.1.1 remote-as 40000 neighbor 172.22.1.1 local-as 50000 no-prepend neighbor 172.22.1.1 ebgp-multihop 2 neighbor 172.22.1.1 activate neighbor 172.22.1.1 allowas-in 1 no auto-summary no synchronization bgp router-id 10.99.1.1 exit-address-family ! address-family ipv4 vrf vrf_trans redistribute connected neighbor 172.23.1.1 remote-as 50000 neighbor 172.23.1.1 local-as 40000 no-prepend neighbor 172.23.1.1 ebgp-multihop 2 neighbor 172.23.1.1 activate neighbor 172.23.1.1 allowas-in 1 no auto-summary no synchronization bgp router-id 10.99.1.2 exit-address-family
After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name:
Router# show ip bgp vpnv4 all
BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.1.2
*> 172.22.0.0 0.0.0.0 0 32768 ?
r> 172.23.0.0 172.23.1.1 0 0 3 1 ?
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
*> 10.52.1.0/24 172.23.1.1 0 3 1 ?
*> 10.52.2.1/32 172.23.1.1 0 3 1 3 i
*> 10.52.3.1/32 172.23.1.1 0 3 1 3 i
*> 10.99.1.1/32 172.23.1.1 0 0 3 1 ?
*> 10.99.2.2/32 0.0.0.0 0 32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0 172.22.1.1 0 0 2 1 ?
*> 172.23.0.0 0.0.0.0 0 32768 ?
*> 10.21.1.1/32 172.22.1.1 0 2 1 2 i
*>i10.52.1.0/24 192.168.3.1 0 100 0 ?
*>i10.52.2.1/32 192.168.3.1 0 100 0 3 i
*>i10.52.3.1/32 192.168.3.1 0 100 0 3 i
*> 10.99.1.1/32 0.0.0.0 0 32768 ?
*> 10.99.2.2/32 172.22.1.1 0 0 2 1 ?
The output of the show ip bgp vpnv4 vrf command for a specified VRF displays the router ID in the output header:
Router# show ip bgp vpnv4 vrf vrf_user
BGP table version is 43, local router ID is 10.99.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0 172.22.1.1 0 0 2 1 ?
*> 172.23.0.0 0.0.0.0 0 32768 ?
*> 10.21.1.1/32 172.22.1.1 0 2 1 2 i
*>i10.52.1.0/24 192.168.3.1 0 100 0 ?
*>i10.52.2.1/32 192.168.3.1 0 100 0 3 i
*>i10.52.3.1/32 192.168.3.1 0 100 0 3 i
*> 10.99.1.1/32 0.0.0.0 0 32768 ?
*> 10.99.2.2/32 172.22.1.1 0 0 2 1 ?
The output of the show ip bgp vpnv4 vrf summary command for a specified VRF displays the router ID in the first line of the output:
Router# show ip bgp vpnv4 vrf vrf_user summary
BGP router identifier 10.99.1.1, local AS number 45000
BGP table version is 43, main routing table version 43
8 network entries using 1128 bytes of memory
8 path entries using 544 bytes of memory
16/10 BGP path/bestpath attribute entries using 1856 bytes of memory
6 BGP AS-PATH entries using 144 bytes of memory
3 BGP extended community entries using 72 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 using 3744 total bytes of memory
BGP activity 17/0 prefixes, 17/0 paths, scan interval 15 secs
Neighbor V AS MsgRcvd MsgSent TblVer InQ OutQ Up/Down State/PfxRcd
172.22.1.1 4 2 20 21 43 0 0 00:12:33 3
When the path is sourced in the VRF, the correct router ID is displayed in the output of the show ip bgp vpnv4 vrfcommand for a specified VRF and network address:
Router# show ip bgp vpnv4 vrf vrf_user 172.23.0.0
BGP routing table entry for 65500:1:172.23.0.0/8, version 22
Paths: (1 available, best #1, table vrf_user)
Advertised to update-groups:
2 3
Local
0.0.0.0 from 0.0.0.0 (10.99.1.1)
Origin incomplete, metric 0, localpref 100, weight 32768, valid, sourced, best
Extended Community: RT:65500:1
Automatically Assigning a BGP Router ID per VRF Examples
The following three configuration examples show different methods of configuring BGP to automatically assign a separate router ID to each VRF instance:
Globally Automatically Assigned Router ID Using Loopback Interface IP Addresses
The following example shows how to configure two VRFs--vrf_trans and vrf_user--with sessions between each other on the same router. Under router configuration mode, BGP is globally configured to automatically assign each VRF a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF.
ip vrf vrf_trans rd 45000:1 route-target export 50000:50 route-target import 40000:1 ! ip vrf vrf_user rd 65500:1 route-target export 65500:1 route-target import 65500:1 ! interface Loopback0 ip address 10.1.1.1 255.255.255.255 ! interface Loopback1 ip vrf forwarding vrf_user ip address 10.99.1.1 255.255.255.255 ! interface Loopback2 ip vrf forwarding vrf_trans ip address 10.99.2.2 255.255.255.255 ! interface Ethernet0/0 ip vrf forwarding vrf_trans ip address 172.22.1.1 255.0.0.0 ! interface Ethernet1/0 ip vrf forwarding vrf_user ip address 172.23.1.1 255.0.0.0 ! router bgp 45000 bgp router-id vrf auto-assign no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 192.168.3.1 remote-as 45000 neighbor 192.168.3.1 update-source Loopback0 ! address-family vpnv4 neighbor 192.168.3.1 activate neighbor 192.168.3.1 send-community extended exit-address-family ! address-family ipv4 vrf vrf_user redistribute connected neighbor 172.22.1.1 remote-as 40000 neighbor 172.22.1.1 local-as 50000 no-prepend neighbor 172.22.1.1 ebgp-multihop 2 neighbor 172.22.1.1 activate neighbor 172.22.1.1 allowas-in 1 no auto-summary no synchronization exit-address-family ! address-family ipv4 vrf vrf_trans redistribute connected neighbor 172.23.1.1 remote-as 50000 neighbor 172.23.1.1 local-as 2 no-prepend neighbor 172.23.1.1 ebgp-multihop 2 neighbor 172.23.1.1 activate neighbor 172.23.1.1 allowas-in 1 no auto-summary no synchronization exit-address-family
After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2. The router IDs are the same as in the Manually Configuring a BGP Router ID per VRF Examples.
Router# show ip bgp vpnv4 all
BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0 0.0.0.0 0 32768 ?
r> 172.23.0.0 172.23.1.1 0 0 3 1 ?
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
*> 10.52.1.0/24 172.23.1.1 0 3 1 ?
*> 10.52.2.1/32 172.23.1.1 0 3 1 3 i
*> 10.52.3.1/32 172.23.1.1 0 3 1 3 i
*> 10.99.1.1/32 172.23.1.1 0 0 3 1 ?
*> 10.99.1.2/32 0.0.0.0 0 32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0 172.22.1.1 0 0 2 1 ?
*> 172.23.0.0 0.0.0.0 0 32768 ?
*> 10.21.1.1/32 172.22.1.1 0 2 1 2 i
*>i10.52.1.0/24 192.168.3.1 0 100 0 ?
*>i10.52.2.1/32 192.168.3.1 0 100 0 3 i
*>i10.52.3.1/32 192.168.3.1 0 100 0 3 i
*> 10.99.1.1/32 0.0.0.0 0 32768 ?
*> 10.99.1.2/32 172.22.1.1 0 0 2 1 ?
Globally Automatically Assigned Router ID with No Default Router ID
The following example shows how to configure a router and associate a VRF that is automatically assigned a BGP router ID when no default router ID is allocated.
ip vrf vpn1 rd 45000:1 route-target export 45000:1 route-target import 45000:1 ! interface Loopback0 ip vrf forwarding vpn1 ip address 10.1.1.1 255.255.255.255 ! interface Ethernet0/0 ip vrf forwarding vpn1 ip address 172.22.1.1 255.0.0.0 ! router bgp 45000 bgp router-id vrf auto-assign no bgp default ipv4-unicast bgp log-neighbor-changes ! address-family ipv4 vrf vpn1 neighbor 172.22.1.2 remote-as 40000 neighbor 172.22.1.2 activate no auto-summary no synchronization exit-address-family
Assuming that a second router is configured to establish a session between the two routers, the output of the show ip interface brief command shows only the VRF interfaces that are configured.
Router# show ip interface brief
Interface IP-Address OK? Method Status Protocol
Ethernet0/0 172.22.1.1 YES NVRAM up up
Ethernet1/0 unassigned YES NVRAM administratively down down
Serial2/0 unassigned YES NVRAM administratively down down
Serial3/0 unassigned YES NVRAM administratively down down
Loopback0 10.1.1.1 YES NVRAM up up
The show ip vrf command can be used to verify that a router ID is assigned for the VRF:
Router# show ip vrf
Name Default RD Interfaces
vpn1 45000:1 Loopback0
Ethernet0/0
VRF session is established:
Per-VRF Automatically Assigned Router ID
The following example shows how to configure two VRFs--vrf_trans and vrf_user--with sessions between each other on the same router. Under the IPv4 address family associated with an individual VRF, BGP is configured to automatically assign a BGP router ID. Loopback interfaces are associated with individual VRFs to source an IP address for the router ID. The output of the show ip bgp vpnv4 command can be used to verify that the router IDs have been configured for each VRF.
ip vrf vrf_trans rd 45000:1 route-target export 50000:50 route-target import 40000:1 ! ip vrf vrf_user rd 65500:1 route-target export 65500:1 route-target import 65500:1 ! interface Loopback0 ip address 10.1.1.1 255.255.255.255 ! interface Loopback1 ip vrf forwarding vrf_user ip address 10.99.1.1 255.255.255.255 ! interface Loopback2 ip vrf forwarding vrf_trans ip address 10.99.2.2 255.255.255.255 ! interface Ethernet0/0 ip vrf forwarding vrf_trans ip address 172.22.1.1 255.0.0.0 ! interface Ethernet1/0 ip vrf forwarding vrf_user ip address 172.23.1.1 255.0.0.0 ! router bgp 45000 no bgp default ipv4-unicast bgp log-neighbor-changes neighbor 192.168.3.1 remote-as 45000 neighbor 192.168.3.1 update-source Loopback0 ! address-family vpnv4 neighbor 192.168.3.1 activate neighbor 192.168.3.1 send-community extended exit-address-family ! address-family ipv4 vrf vrf_user redistribute connected neighbor 172.22.1.1 remote-as 40000 neighbor 172.22.1.1 local-as 50000 no-prepend neighbor 172.22.1.1 ebgp-multihop 2 neighbor 172.22.1.1 activate neighbor 172.22.1.1 allowas-in 1 no auto-summary no synchronization bgp router-id auto-assign exit-address-family ! address-family ipv4 vrf vrf_trans redistribute connected neighbor 172.23.1.1 remote-as 50000 neighbor 172.23.1.1 local-as 40000 no-prepend neighbor 172.23.1.1 ebgp-multihop 2 neighbor 172.23.1.1 activate neighbor 172.23.1.1 allowas-in 1 no auto-summary no synchronization bgp router-id auto-assign exit-address-family
After the configuration, the output of the show ip bgp vpnv4 all command shows the router ID displayed next to the VRF name. Note that the router IDs used in this example are sourced from the IP addresses configured for loopback interface 1 and loopback interface 2.
Router# show ip bgp vpnv4 all
BGP table version is 43, local router ID is 10.1.1.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete
Network Next Hop Metric LocPrf Weight Path
Route Distinguisher: 45000:1 (default for vrf vrf_trans) VRF Router ID 10.99.2.2
*> 172.22.0.0 0.0.0.0 0 32768 ?
r> 172.23.0.0 172.23.1.1 0 0 3 1 ?
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
*> 10.52.1.0/24 172.23.1.1 0 3 1 ?
*> 10.52.2.1/32 172.23.1.1 0 3 1 3 i
*> 10.52.3.1/32 172.23.1.1 0 3 1 3 i
*> 10.99.1.1/32 172.23.1.1 0 0 3 1 ?
*> 10.99.1.2/32 0.0.0.0 0 32768 ?
Route Distinguisher: 50000:1
*>i10.21.1.1/32 192.168.3.1 0 100 0 2 i
Route Distinguisher: 65500:1 (default for vrf vrf_user) VRF Router ID 10.99.1.1
r> 172.22.0.0 172.22.1.1 0 0 2 1 ?
*> 172.23.0.0 0.0.0.0 0 32768 ?
*> 10.21.1.1/32 172.22.1.1 0 2 1 2 i
*>i10.52.1.0/24 192.168.3.1 0 100 0 ?
*>i10.52.2.1/32 192.168.3.1 0 100 0 3 i
*>i10.52.3.1/32 192.168.3.1 0 100 0 3 i
*> 10.99.1.1/32 0.0.0.0 0 32768 ?
*> 10.99.1.2/32 172.22.1.1 0 0 2 1 ?
Additional References
The following sections provide references related to the Per-VRF Assignment of BGP Router ID feature.
Related Documents
Related Topic |
Document Title |
---|---|
BGP commands: complete command syntax, defaults, command mode, command history, usage guidelines, and examples |
Cisco IOS IP Routing: BGP Command Reference |
MPLS commands: complete command syntax, defaults, command mode, command history, usage guidelines, and examples |
Cisco IOS Multiprotocol Label Switching Command Reference |
Standards
Standard |
Title |
---|---|
No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
-- |
MIBs
MIB |
MIBs Link |
---|---|
No new or modified MIBs are supported by this feature, and support for existing MIBs has not been modified by this feature. |
To locate and download MIBs for selected platforms, Cisco IOS releases, and feature sets, use Cisco MIB Locator found at the following URL: |
RFCs
RFC |
Title |
---|---|
No new or modified RFCs are supported by this feature, and support for existing RFCs has not been modified by this feature. |
-- |
Technical Assistance
Description |
Link |
---|---|
The Cisco Support website provides extensive online resources, including documentation and tools for troubleshooting and resolving technical issues with Cisco products and technologies. To receive security and technical information about your products, you can subscribe to various services, such as the Product Alert Tool (accessed from Field Notices), the Cisco Technical Services Newsletter, and Really Simple Syndication (RSS) Feeds. Access to most tools on the Cisco Support website requires a Cisco.com user ID and password. |
Command Reference
The following commands are introduced or modified in the feature or features documented in this module. For information about these commands, see the Cisco IOS IP Routing: BGP Command Reference. For information about all Cisco IOS commands, use the Command Lookup Tool at http://tools.cisco.com/Support/CLILookup or the Cisco IOS Master Command List, All Releases, at http://www.cisco.com/en/US/docs/ios/mcl/allreleasemcl/all_book.html.
Feature Information for Per-VRF Assignment of BGP Router ID
The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to www.cisco.com/go/cfn. An account on Cisco.com is not required.
Table 1 | Feature Information for Per-VRF Assignment of BGP Router ID |
Feature Name |
Releases |
Feature Information |
---|---|---|
Per-VRF Assignment of BGP Router ID |
12.2(31)SB2 12.2(33)SRA 12.2(33)SXH 12.4(20)T 15.0(1)S |
The Per-VRF Assignment of BGP Router ID feature introduces the ability to have VRF-to-VRF peering in Border Gateway Protocol (BGP) on the same router. BGP is designed to refuse a session with itself because of the router ID check. The per-VRF assignment feature allows a separate router ID per VRF using a new keyword in the existing bgp router-id command. The router ID can be manually configured for each VRF or can be assigned automatically either globally under address family configuration mode or for each VRF. The following commands were introduced or modified by this feature: bgp router-id, show ip bgp vpnv4. |
Cisco and the Cisco Logo are trademarks of Cisco Systems, Inc. and/or its affiliates in the U.S. and other countries. A listing of Cisco's trademarks can be found at www.cisco.com/go/trademarks. Third party trademarks mentioned are the property of their respective owners. The use of the word partner does not imply a partnership relationship between Cisco and any other company. (1005R)
Any Internet Protocol (IP) addresses and phone numbers used in this document are not intended to be actual addresses and phone numbers. Any examples, command display output, network topology diagrams, and other figures included in the document are shown for illustrative purposes only. Any use of actual IP addresses or phone numbers in illustrative content is unintentional and coincidental.