A problem was reported that the 10.10.10.0/24 prefix was not injected into the local BGP
table on Router A. The following information is available from Router A.
Why is this prefix not in the local BGP table?
Configuration:
router bgp 65001
network 10.0.0.0
neighbor 172.16.1.1 remote-as 65002
no auto-summary
Routing table information:
show ip route | include 10
O 10.10.10.0/24 [110/11] via 192.168.1.1, 2d00h, Ethernet0/0
A.
This route is not a BGP learned route.
B.
The network command is wrong.
C.
The 172.16.1.1 neighbor is down.
D.
The prefix 10.10.10.0/24 is not ‘connected’ route.
Explanation:
The network command is used with IGPs, such as RIP,to determine the interfaces on which
to send and receive updates. The command also indicates which directly connected
networks to advertise. However, when configuring BGP, the network command does not
affect what interfaces BGP runs on. Therefore, configuring just a network statement will not
establish a BGP neighbor relationship. This is a major difference between BGP and IGPs.
The network statement follows this syntax:
Router(config-router)#network network-number [mask network-mask]
In BGP, the network command tells the BGP process what locally learned networks to
advertise. The networks can be connected routes, static routes, or routes learned by way of
a dynamic routing protocol, such as RIP. These networks must also exist in the routing table
of the local router or they will not be sent out inupdates. The mask keyword can be used
with the network command to specify individual subnets. Routes learned by the BGP
process are propagated by default but are often filtered by a routing policy.