I have a few queries regarding the utilization of SoO attribute:
1. use of SoO is understandable in case eBGP is the PE/CE routing protocol.
- If SoO is not configured, chelmford CE router will accept the the eBGP update for 126.96.36.199/24 since the route is originated from another CE within its own AS and the chelmsford-CE might have recieved it from Newyork-CE as iBGP route. Since the weight attribute of received routes is 0 the preference would be made on eBGP vs iBGP criteria.
- If SoO is not configured chelmsfor-CE will not be able to differentiate whether a route received is from its own site (by another CE) or from other site within the same VPN , because of asoverride configuration.
Therefore SoO is necessary in case eBGP is the PE/CE RP.
in case of IGPs/Static/connected.. do we need SoO ????
since IGP updates from a CE will always be prefered over iBGP updates from other PEs on a PE and similarly on a CE
and in case of eBGP it is required since eBGP route is prefered over iBGP route on a PE and on CE...