Which statement best describes the established state outcome?

• A. Peering is established and routing begins.
• B. The IP addresses are added to the IGP.
• C. The BGP table is reset.
• D. An update is rejected.

Answer: (A)

In BGP, when the session with a neighbor reaches the Established state, peering is up and routing information can flow between the peers. This means OPEN messages were exchanged successfully, the TCP session is stable, and both sides are ready to exchange UPDATE messages. Once in this state, routes learned from the neighbor are announced and, after the decision process, can be installed into the local routing table, so actual routing can begin.

The other statements don’t describe the Established state. Adding IP addresses to the IGP isn’t part of the BGP session becoming established—IGP operates separately. The BGP table reset happens if the session drops or restarts, not when it’s established. An update being rejected can occur for various reasons, but it isn’t the defining outcome of entering the Established state.