> > > Hi Tian, > As fas as I know, the $ns upstream-node call just looks up the > routing table for the next hop. so you might want to check if > recomputation of the routing table is done after the link 0-1 goes down, > and the correct nexthop value is generated. Thanks a lot, but how can I know the routing table is done? Tian, > > --Padma. > > > > >