Perhaps the problem here is more about terminology than about real functionality. The default route that is advertised by the ABR into the stub area gives the OSPF routers within the stub area a direction in which to forward packets whose destination is external to OSPF.
Perhaps it may help to think of it in this way: the External LSAs that are not flooded into the stub area represent destinations that are external to OSPF. The OSPF routers within the stub area will have LSAs that advertise all of the destinations that are within OSPF so they can accurately forward traffic to any destination that is within OSPF. But these routers within the stub area do not have LSAs for external destinations. So the ABR sends an LSA advertisement that gives the routers within the stub area an entry that they can use to forward to the external destinations.
[toc:faq]The ProblemOn traditional switches whenever we have a trunk
interface we use the VLAN tag to demultiplex the VLANs. The switch needs
to determine which MAC Address table to look in for a forwarding
decision. To do this we require the switch to do...
[toc:faq]Introduction:Netdr is a tool available on a RSP720, Sup720 or
Sup32 that allows one to capture packets on the RP or SP inband. The
netdr command can be used to capture both Tx and Rx packets in the
software switching path. This is not a substitut...
IntroductionOSPF, being a link-state protocol, allows for every router
in the network to know of every link and OSPF speaker in the entire
network. From this picture each router independently runs the Shortest
Path First (SPF) algorithm to determine the b...