EIGRP STUBS

Charter 14

To talk about stub router we need to understand first the query process..

When EIGRP removes a successor router and no FS exists, the router begins a process of router discovery to reach that prefix.It's called "Going active"

So, it change the state , as you could see in "show ip eigrp" command from passive to active

We will send EIGRP message to every neighbor except the neighbor in the failed route

When a router receive a Reply message from all neighbors to it sent any query message, that router can send a reply message to any of it's neighbors as necessary

When a Router has received a Reply for all its query message , that router can use the best route and confirm it's loop free

Parameters for EIGRP Stub Command

Basically in this way we can minimize half of traffic..

What do we see here?

R2 ( the second Router ) Got a serial and fa interface conection to other routers and have several loop back address interfaces

10.12..0.0 /30 means it's a 255.255.255.252..the rest (24) it's a 255.255.255.0 connection

Please copy and paste
int s0/0
ip address 10.12.0.1 255.255.255.252
no shut

int fa0/0
ip address 192.168.0.1 255.255.255.0
no shut

int s0/0
ip address 10.12.0.1 255.255.255.0
no shut
int loopback2
ip address 10.2.0.1 255.255.255.0
no shut
int loopback0
ip address 10.1.0.1 255.255.255.0
no shut
int loopback3
ip address 10.3.0.1 255.255.255.0
no shut
int loopback1
ip address 10.1.0.1 255.255.255.0
no shu

You will eventually have this:

we will do the same on R1

We will do a small exercise:

In R2 we will do a #show ip int brief
In R1#debug ip eigrp
In R2 we will do a copy and paste:
conf t
int fa0/0
shut

and we will see the query process on R1 and after that the Reply on R2!

Now let's declare R1 as a stub router:
R1#router eigrp 100
R1#eigrp stub