Refer to the exhibit.
The Route.com company is running EIGRP between all the routers. Currently, if one of the LAN
links (LAN1 or LAN2) at the headquarters flaps (goes up and down), the HQ-RTR1 and HQ-RTR2
routers will experience high CPU usage and have a long EIGRP convergence time. As the new
network administrator, you are asked to investigate this situation and determine if there is a quick
way to resolve this issue.
Which is the most important thing that you can quickly verify first to resolve this issue?
A.
Verify that the bandwidth setting on all WAN links is correct.
B.
Verify that the HQ-RTR1 and HQ-RTR2 routers are configured to send only a default route to
all the spoke routers.
C.
Verify that the HQ-RTR1 and HQ-RTR2 routers are configured for EIGRP Nonstop Forwarding.
D.
Verify that all the spoke routers are configured for auto summarization.
E.
Verify that all the spoke routers are configured as EIGRP stub.
Explanation:
Stub routing is commonly used in a hub and spoke network topology. In a hub and
spoke network, one or more end (stub) networks are connected to a remote router (the spoke) that
is connected to one or more distribution routers (the hub). The remote router is adjacent only to
one or more distribution routers. The only route for IP traffic to follow into the remote router is
through a distribution router. This type of configuration is commonly used in WAN topologies
where the distribution router is directly connected to a WAN. The distribution router can be
connected to many more remote routers. Often, the distribution router will be connected to 100 or
more remote routers. In a hub and spoke topology, the remote router must forward all nonlocal
traffic to a distribution router, so it becomes unnecessary for the remote router to hold a complete
routing table. Generally, the distribution router need not send anything more than a default route to
the remote router.
When using the EIGRP Stub Routing feature, you need to configure the distribution and remote
routers to use EIGRP, and to configure only the remote router as a stub. Only specified routes are
propagated from the remote (stub) router. The router responds to queries for summaries,
connected routes, redistributed static routes, external routes, and internal routes with the message
“inaccessible.” A router that is configured as a stub will send a special peer information packet to
all neighboring routers to report its status as a stub router.
Any neighbor that receives a packet informing it of the stub status will not query the stub router for
any routes, and a router that has a stub peer will not query that peer. The stub router will depend
on the distribution router to send the proper updates to all peers.http://www.cisco.com/en/US/docs/ios/12_0s/feature/guide/eigrpstb.html