Passive Interface and Stuck in Active concepts in EIGRP

Stuck in Active:

When a router lost any one route (route went down) then it will start query about that down route to the neighbor routers. And the neighbor router will send query to next and so on until they get reply about that route. During this mean time all routers went too stuck in active mode.

STUB Router is used to eliminate this stuck in active problem. Stub router won’t receive query, reply to query etc.

#router eigrp 100

#eigrp stub

NOTE:

Ø  Stub router won’t send the redistributed routes from any router to other

# eigrp stub redistribute                     (won’t work)

Ø  If the redistribution takes place in the stub router then only it will send all the redistributed routes to all other routers

# eigrp stub redistribute                     (will work)

IP Default Network Command:

Her R3 is connected to ISP, by making a static or default route R3 will ping to ISP. But R1 and R2 won’t ping. To eliminate this we will assign an IP default Network command in R3. So that a default route will generate in all routers R1, R2 whenever they didn’t not found the route then they will send that packets to the R3, then R3 will forward that packets

R3:

#conf t

#ip default-network 50.0.0.0

#int loop p

#Ip add 50.0.0.1 255.0.0.0

#router eigrp 1

#network 50.0.0.1 0.0.0.0

Passive Interface in EIGRP:

When we configure an interface with a Passive interface in EIGRP, then the whole neighbourship will goes down. So, in EIGRP we will make Passive Interface the interface which is connected to a LAN network to reduce the bandwidth utilization in network. This is for Security reason also.

How to avoid stuck in active problem?

Stub - it won’t receive Query packets, if any route in this stub router down then only it will send query packets

Summarization - it will send group of routes as a single route, if any one route down the next router wont recognized it. In this way we can avoid stuck in active.