Interface index for the interface from which the source address for peer sessions in this group is chosen. If non-zero, BGP will look for the first address on this interface with a type matching bgpPeerRemoteAddrType, and use that as the source address. If no matching address or interface exists, or this field is set to zero, the source address is chosen as described in bgpPeerLocalAddr. This field is ignored for peers identified only by interface (bgpPeerLocalAddr and bgpPeerRemoteAddr are both zero). If non-zero, for dynamic peers, the local address of the incoming TCP connection must match an address on this interface, or else the connection is rejected. This field is only taken into account for peer-group members if the conditions described in the bgpPeerTable description are met. This field can be changed at any time. However, if a peer is configured to use the peer group field and the field is changed while the peer is row_status ACTIVE, the change will only take effect after the peer has been cycled row_status NOT_IN_SERVICE and then ACTIVE, thus forcing the peer session to be recreated. In this case, until the peer is set row_status NOT_IN_SERVICE, the peer will be marked as out of date (as reported by the config_state field in the AMB_BGP_PEER_STATUS row for the peer).