BGP As Path Prepending Neighbor AS

[nwekechampion]

Hey guys,

Just a quick one, what would be the effect of prepending neighbors AS in BGP update? Would it achieve the same results as prepending my own AS to Neighbor?

[MHM Cisco World]

No 

If you do as prepend in your router then you effect inbound traffic.

If your neighbor do as prepend the  it will effect your outbound traffic.

[nwekechampion]

Thanks I meant what if I did AS prepend with my nieghbors AS instead of my AS?

[MHM Cisco World · Accepted solution]

Your neighbor will drop it' this one of loop prevent bgp use' if router see it as in as path attribute it assume loop and drop prefix.

[nwekechampion]

Thank you