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This chapter describes the Cisco NX-OS Border Gateway Protocol (BGP) commands that begin with T.
To create a peer template and enter a peer template configuration mode, use the template command. To remove a peer template, use the no form of this command.
template { peer name | peer-policy name | peer-session name }
no template { peer name | peer-policy name | peer-session name }
Neighbor address-family configuration mode
Router bgp configuration mode
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The template command allows you to enable a set of predefined attributes that a neighbor inherits.
Note A Border Gateway Protocol (BGP) neighbor cannot be configured to work with both peer groups and peer templates. A BGP neighbor can be configured to belong to a peer group or to inherit policies from peer templates only.
Peer templates support only general policy commands. BGP policy configuration commands that are configured only for specific address families or NLRI configuration modes are configured with peer templates.
When you enter the peer-policy template configuration mode, the following commands are available:
– in —Applies the access list to incoming routes.
– out —Applies the access list to outgoing routes.
The sequence number specifies the order in which the peer policy template is evaluated. Like a route-map sequence number, the lowest sequence number is evaluated first. Peer policy templates support inheritance and a peer can directly and indirectly inherit up to seven peer policy templates. Inherited peer policy templates are configured with sequence numbers like route maps. An inherited peer policy template, like a route map, is evaluated starting with the inherit statement with the lowest sequence number. However, peer policy templates do not fall through. Every sequence is evaluated. If a BGP policy command is reapplied with a different value, it overwrites any previous value from a lower sequence number.
Note A Border Gateway Protocol (BGP) routing process cannot be configured to be a member of a peer group and to use peer templates for group configurations. You must use one method or the other. We recommend peer templates because they provide improved performance and scalability.
– in —Applies the prefix list to incoming routes.
– out —Applies the prefix list to outgoing routes.
– in —Applies the route map to incoming routes.
– out —Applies the route map to outgoing routes.
By default, all internal BGP (iBGP) speakers in an autonomous system must be fully meshed, and neighbors do not readvertise iBGP learned routes to neighbors, which prevents a routing information loop. When all the clients are disabled, the local router is no longer a route reflector.
If you use route reflectors, all iBGP speakers need not be fully meshed. In the route reflector model, an Interior BGP peer is configured to be a route reflector responsible for passing iBGP learned routes to iBGP neighbors. This scheme eliminates the need for each router to talk to every other router.
All the neighbors configured with this command are members of the client group and the remaining iBGP peers are members of the nonclient group for the local route reflector.
To use soft reconfiguration, or a soft reset, without preconfiguration, both BGP peers must support the soft route refresh capability, which is advertised in the open message sent when the peers establish a TCP session. Clearing the BGP session using the soft-reconfiguration command has a negative effect on network operations and should only be used as a last resort.
To determine whether a BGP router supports this capability, use the show ip bgp neighbors command. If a router supports the route refresh capability, the following message appears:
“Received route refresh capability from peer.”
If you specify a BGP peer group by using the peer-group-name argument, all the members of the peer group inherit the characteristic configured with this command.
When you enter the peer-session template configuration mode, the following commands are available:
Note You should enter this command under the guidance of Cisco technical support staff only.
– 0 password —Specifies an unencrypted neighbor password.
– 3 password —Specifies an 3DES encrypted neighbor password
– password —Specifies an unencrypted (cleartext) neighbor password
General session commands can be configured once in a peer-session template and then applied to many neighbors through the direct application of a peer-session template or through indirect inheritance from a peer-session template. The configuration of peer-session templates simplify the configuration of general session commands that are commonly applied to all neighbors within an autonomous system.
This example shows how to create a peer-session template named CORE1. This example inherits the configuration of the peer-session template named INTERNAL-BGP.
This example shows how to create and configure a peer-policy template named CUSTOMER-A:
This example shows that the maximum prefixes that are accepted from the 192.168.1.1 neighbor is set to 1000:
This example shows that the maximum number of prefixes that are accepted from the 192.168.2.2 neighbor is set to 5000. The router is also configured to display warning messages when 50 percent of the maximum-prefix limit (2500 prefixes) has been reached.
This example shows that the maximum number of prefixes that are accepted from the 192.168.3.3 neighbor is set to 2000. The router is also configured to reestablish a disabled peering session after 30 minutes.
This example shows that the warning messages are displayed when the maximum-prefix limit (500) for the 192.168.4.4 neighbor is exceeded:
This example forces all updates destined for 10.108.1.1 to advertise this router as the next hop:
This example shows that the router belongs to autonomous system 109 and is configured to send the communities attribute to its neighbor at IP address 172.16.70.23:
This example shows that the router belongs to autonomous system 109 and is configured to send the communities attribute to its neighbor at IP address 172.16.70.23:
This example enables inbound soft reconfiguration for the neighbor 10.108.1.1. All the updates received from this neighbor are stored unmodified, regardless of the inbound policy. When inbound soft reconfiguration is done later, the stored information is used to generate a new set of inbound updates.
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Enters the address family mode for the Border Gateway Protocol (BGP). |
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Enters the assign an autonomous system (AS) number to a router and enters the router BGP configuration mode. |