Which BGP configuration parameter allows the router to wait for the peer to initiate the open request?

The parameter that allows a router to wait for the peer to initiate the open request in a Border Gateway Protocol (BGP) configuration is the option that is commonly referred to in the context of BGP settings as "Passive." This mode is specifically used to ensure that the local router does not attempt to establish a connection to the peer but is instead ready to accept incoming connections.

When BGP is configured in passive mode, the router will listen for incoming connections from its peers rather than actively trying to establish a session. This can be useful in certain network designs where it is preferable for one peer to dictate when the session starts, such as when managing a large number of peers or creating specific routing architectures.

The other options do not relate to the ability of a router to wait for a peer's connection initiation. For instance, hold-time specifies how long a router will wait to receive a keepalive or update message from a peer before considering the peer to be down, while accept-remote-nexthop deals with how remote next-hop attributes are treated for routes. Out-delay often pertains to timers used while processing updates and does not influence the establishment of the TCP session itself. Thus, choosing to set the BGP session to passive mode effectively positions the router