BGP configuration

We already configured the IP address and IGP(OSPF) is enabled.

Lets form as eBGP peer with R5 and R4 with a direct link.

R4(config)#router bgp 500

R4(config-router)#neighbor 155.1.45.5 remote-as 500

R5(config)#router bgp 500

R5(config-router)#neighbor 155.1.45.4 remote-as 400

Here the R4 using process

R4#sh processes cpu | in BGP

 193          28      3596          7  0.00%  0.00%  0.00%   0 BGP Router

 194           0         1          0  0.00%  0.00%  0.00%   0 BGP I/O

 195         640       120       5333  0.00%  0.04%  0.00%   0 BGP Scanner

 196         244       115       2121  0.00%  0.00%  0.00%   0 BGP Open

R4#sh processes mem | in BGP

 193   0      24144          0      10200          2          2 BGP Router

 194   0          0          0       6972          0          0 BGP I/O

 195   0          0          0       9972          8          8 BGP Scanner

 196   0      69832      69832       6972         58         58 BGP Open

R4#sh tcp brief all

TCB       Local Address           Foreign Address        (state)

65B32764  155.1.45.4.42521        155.1.45.5.179         ESTAB

R5#sh bgp sum

BGP router identifier 150.5.5.5, local AS number 500

BGP table version is 1, main routing table version 1

Neighbor        V    AS MsgRcvd MsgSent   TblVer  InQ OutQ Up/Down  State/PfxRcd

155.1.45.4      4   400       5       5        1    0    0 00:01:54        0