BGP neighbor groups
A BGP neighbor group is a configuration template that:
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stores address family-independent and address family-dependent settings
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enables multiple BGP neighbors to inherit shared configuration parameters, and
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allows centralized management and consistent application of BGP neighbor policies.
Configuration inheritance
After you configure a neighbor group, each BGP neighbor can inherit its configuration by using the use command. By default, a neighbor configured to use a neighbor group inherits all configuration from that group, including address family-independent and address family-dependent settings.
Overriding inherited configuration
You can override inherited settings by directly configuring commands for the neighbor. Alternatively, associate session groups or address family groups with the neighbor using the use command
Configuring address family-independent parameters
Configure address family-independent parameters directly within the neighbor group configuration mode.
Configuring address family-dependent parameters
To configure address family-dependent parameters, enter the address family submode under the neighbor group by using the address-family command.
Assigning options to a neighbor group
After specifying the neighbor group name with the neighbor group command, assign the configuration options you want the group to use. Downstream neighbors inherit these options.
Suppose you have several BGP neighbors that require the same password and update-source configuration. Instead of configuring these parameters for each neighbor individually, define them in a neighbor group and attach the group to each neighbor with the use command.
Configure a BGP neighbor group
Centralize and streamline BGP configuration by creating a BGP neighbor group and applying its settings to BGP neighbors.
BGP neighbor groups let you manage common settings, such as address family, remote AS number, and route policies across multiple BGP neighbors. By grouping neighbors with similar configurations, you can simplify management and reduce configuration errors.
Before you begin
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Ensure you have administrative access to the command-line interface of the router.
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Verify that the router supports BGP and is properly licensed.
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Identify the autonomous system (AS) numbers and IP addresses for both local and remote peers.
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Prepare any required route policies to apply to the neighbor group.
Follow these steps to configure a BGP neighbor group and apply it to a neighbor:
Procedure
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Step 1 |
Enter BGP configuration mode and specify the local AS number and address family (such as IPv4 or IPv6 unicast). Example: |
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Step 2 |
Configure a neighbor group by specifying a remote autonomous system (AS) number for that group. Apply the address family, such as IPv4 or IPv6, to the BGP neighbor group. Additionally, you can apply inbound or outbound route policies to that neighbor group. Example: |
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Step 3 |
Configure a BGP neighbor to inherit configuration from the specified neighbor group. Example: |
Example
This example illustrates centralized configuration using BGP neighbor groups and route policies:
route-policy pass-all
pass
end-policy
router bgp 109
address-family ipv4 unicast
network 172.16.0.0 255.255.0.0
network 192.16831.7.0 255.255.0.0
neighbor 172.16.200.1
remote-as 167
exit
address-family ipv4 unicast
route-policy pass-all in
route-policy pass-out out
neighbor 172.26.234.2
remote-as 109
exit
address-family ipv4 unicast
neighbor 172.26.64.19
remote-as 99
exit
address-family ipv4 unicast
route-policy pass-all in
route-policy pass-all out
In this example:
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The BGP router is configured to belong to AS 109.
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The router advertises two networks, 172.16.0.0 and 192.168.7.0, as originating from AS 109.
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There are three neighbor routers, two external and one internal:
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The first and third neighbors use different AS numbers.
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The second neighbor shares AS 109 and is identified as an internal neighbor.
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Route policies are applied to inbound and outbound routing updates.
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This setup allows the router to share routing information about the two networks with all configured neighbors, while distinguishing between internal and external BGP peers based on the AS number.
What to do next
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Verify the BGP neighbor and group configuration using show commands (for example, show running-config or show bgp neighbors ) to confirm the correct application of settings.
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Monitor BGP peer status and logs to ensure neighbor establishment and exchange of routing information.
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