NexthopRewriteFilter is a BGPRouteFilter that changes the nexthop attribute in a route passing though the filter. A typicaly use is when passing a route to an EBGP peer, we change the nexthop attribute to be our own IP address on the appropriate interface to that peer. If the EBGP peer is on the the same subnet as the router and the NEXT_HOP is on the same subnet the NEXT_HOP should not be rewritten.
| NexthopRewriteFilter (const A &local_nexthop, bool directly_connected,
const IPNet<A> &subnet)
|bool filter (InternalMessage<A>& rtmsg)
Reimplemented from BGPRouteFilter.