Multicast and Routing Guide K/KA/KB.15.15

Allowing establishment of an eBGP connection to a non-directly connected peer
In general, direct physical links should be available between eBGP peers. If not, you can use the
neighbor ip-address ebgp-multihop command to establish a TCP connection over multiple
hops between two peers.
Follow these steps to allow establishment of eBGP connection to a non-directly connected peer.
RemarksUse the command...To do...
configurationEnter global configuration context
bgp as-numberEnter BGP context
Optional. hop-count is 1 by default
for eBGP peers
neighbor
ip-addressebgp-multihop
[hop-count]
Allow the establishment of eBGP
connection to a non-directly connected
peer
Controlling route distribution, reception and advertisement
Prerequisites
Before configuring this task, you should have completed the BGP basic configuration.
Configuring BGP Route Redistribution
You can redistribute IGP routes into BGP. During route redistribution, BGP can filter routing
information from specific routing protocols.
RemarksUse the command...To do...
configurationEnter global configuration context
router bgp as-numberEnter BGP context
Redistributes other protocol routes into
BGP
redistribute static |
connected | ospf | rip
{route-map route-map-name}
Redistribute from other protocols
NOTE: The ORIGIN attribute of routes redistributed using the import-route command is Incomplete.
The ORIGIN attribute of networks advertised into the BGP routing table with the network command
is IGP. These networks must exist in the local IP routing table. Using a routing policy makes route
control more flexible.
Configuring BGP route inbound and outbound filtering policies
Follow these steps to configure BGP route reception filtering policies:
RemarksUse the command...To do...
configurationEnter global Configuration context
bgp as-numberEnter BGP context
neighbor ip-addressroute-map
route-map-name [in | out]
Apply filter policy on the inbound or
the outbound for each peer
CAUTION: Only routes permitted by the specified filtering policies can be installed into the local
BGP routing table.
312 Border Gateway Protocol (BGP)