BGP best route decision question

[mahesh18]

Hi All,

I have two Routers directly connected by EBGP.

R4 and R1  have two conenctions to each other.

1  by serial interface other by loopback.

R1 is advertising the networks to R4.

R4#sh ip bgp
BGP table version is 6, local router ID is 10.4.4.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
              r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incomplete

   Network          Next Hop            Metric LocPrf Weight Path
*> 50.1.1.0/24      1.1.1.1                  0             0 5500 i
*                   10.1.45.1                0             0 5500 i
*> 200.1.1.0        1.1.1.1                  0             0 5500 ?
*                   10.1.45.1                0             0 5500 ?
*> 200.1.2.0        1.1.1.1                  0             0 5500 ?
*                   10.1.45.1                0             0 5500 ?
*> 200.1.3.0        1.1.1.1                  0             0 5500 ?
*                   10.1.45.1                0             0 5500 ?
*> 200.1.4.0        1.1.1.1                  0             0 5500 ?
*                   10.1.45.1                0             0 5500 ?

Here we can see that best path is 1.1.1.1  and thats in routing table also.

i know BGP chooses best route based on some 14 attributes.

Here AS distance,metric,Weight and local preference is same.

Can someone please tell me how R4 choosed 1.1.1.1 as best route?

Thanks

Mahesh

[Roman Rodichev · Accepted solution]

13. Prefer the path that comes from the lowest neighbor address.

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a0080094431.shtml

[mahesh18]

Hi Roman,

Many thanks for correct reply and info on  useful link.

Regards

MAhesh