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Cisco ME 3400 EthernetAccess Switch SoftwareConfiguration Guide
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Chapter32 Configuring IP Unicast Routing
Configuring BGP
To disable an existing BGP neighbor or neighbor peer group, use the neighbor shutdown router
configuration command. To enable a previously existing neighbor or neighbor peer group that had been
disabled, use the no neighbor shutdown router configuration command.
Configuring Aggregate Addresses
Classless interdomain routing (CIDR) enables you to create aggregate routes (o r supernets) to minimize
the size of routing tables. You can configure aggregate routes in BGP either by redistributing an
aggregate route into BGP or by creating an aggregate entry in the BGP routing table. An aggregate
address is added to the BGP table when there is at least one more specific entry in the BGP table.
Beginning in privileged EXEC mode, use these commands to create an agg regate address in the routing
table:
Step18 neighbor {ip-address | peer-group-name} timers
keepalive holdtime (Optional) Set timers for the neighbor or peer group.
•The keepalive interval is the time within which keepalive
messages are sent to peers. The range is 1 to 4294967295
seconds; the default is 60.
•The holdtime is the interval after which a peer is declared
inactive after not receiving a keepalive message from it. The
range is 1 to 4294967295 seconds; the default is 180.
Step19 neighbor {ip-address | peer-group-name} weight
weight (Optional) Specify a weight for all routes from a neighbor.
Step20 neighbor {ip-address | peer-group-name}
distribute-list {access-list-number | name} {in |
out}
(Optional) Filter BGP routing updates to or from neighbors, as
specified in an access list.
Step21 neighbor {ip-address | peer-group-name}
filter-list access-list-number {in | out | weight
weight}
(Optional) Establish a BGP filter.
Step22 neighbor {ip-address | peer-group-name}
version value (Optional) Specify the BGP version to use when communicating
with a neighbor.
Step23 neighbor {ip-address | peer-group-name}
soft-reconfiguration inbound (Optional) Configure the software to start storing received
updates.
Step24 end Return to privileged EXEC mode.
Step25 show ip bgp neighbors Verify the configuration.
Step26 copy running-config startup-config (Optional) Save your entries in the configuration file.
Command Purpose
Command Purpose
Step1 configure terminal Enter global configuration mode.
Step2 router bgp autonomous-system Enter BGP router configuration mode.
Step3 aggregate-address address mask Create an aggregate entry in the BGP routing table. The aggregate
route is advertised as coming from the AS, and the atomic a ggregat e
attribute is set to indicate that information might be missing.