The "i" in the path column as in the below example:
I3_1#sh ip bgp
BGP table version is 4, local router ID is 22.214.171.124
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
*> 126.96.36.199 192.168.1.5 0 0 11 i
*> 172.20.0.0 0.0.0.0 0 32768 i
*> 172.30.0.0 0.0.0.0 0 32768 i
relates to the "Origin codes" above in RED. Key thing to note, i = IGP does not stand for Internal Gateway Protocol nor does e = EGP stand for External BGP. The "e = EGP" stand for the old EGP protocol which has not been used since 12.3 or there abouts and you should not see this in use today. The "i = IGP" stands for routes injected via the "network", "aggregate-address" or "neighbor-default-originte" commands.
If ther is no i just after the > or * sign then this is not an iBGP learned route so it is a locally generated route in which case next-hop is 0.0.0.0 or an eBGP route.
The last I as explained above is for the origin of the route that is how was he first put into the BGP table, it could be i or e or ? where e stands for egp which is predecessor to BGP and ? stands for unknown so was redistributed and i is via a network command or aggregate or the last one cited by Brian( I would have forgot this one).
Hi. I'm stuggling with the difference too. I understand the 'i" at the end means its from "network" or "aggreagate" - i imagine for the AS whose number is to the left of it. This would be the origin in path selection ?? (weight/local pref/route originate/aspath/origin)
So what is the "i" in the 3rd column meaning? Would that mean it originated on the router being looked at as opposed to another router? I think I need an example to clarify