Chris
06-17-2009, 01:05 AM
Hey guys .. trying to workout the differences between local-as and no-export communities ….. Is my understanding correct for cases 1 and 2 below?
local-as – do not advertise route outside local-as to any eBGP peer. If this attribute set in sub-as (inside confederations) then it will not be advertised to any other sub-AS’s (eBGP peers).
no-export – do not advertise to any eBGP peers, but if confederations used, then it can be advertised to other sub-AS’s. If no confederations is used then it works like local-as.
Technicaly if we get a question to make sure that the route should not be advertised outside the local-as (no confederations) then we can use either local-as or no-export as they will work the same.
Case 1 - If we are using confederations and need to stop route from been advertised outside our confederation then we must use local-as.
Case 2 - If we are using confederations and need to stop route from been advertised another sub’AS within our confederation then we must use no-export.
Thanks
local-as – do not advertise route outside local-as to any eBGP peer. If this attribute set in sub-as (inside confederations) then it will not be advertised to any other sub-AS’s (eBGP peers).
no-export – do not advertise to any eBGP peers, but if confederations used, then it can be advertised to other sub-AS’s. If no confederations is used then it works like local-as.
Technicaly if we get a question to make sure that the route should not be advertised outside the local-as (no confederations) then we can use either local-as or no-export as they will work the same.
Case 1 - If we are using confederations and need to stop route from been advertised outside our confederation then we must use local-as.
Case 2 - If we are using confederations and need to stop route from been advertised another sub’AS within our confederation then we must use no-export.
Thanks