i've been trying to configure EIGRP for a simple two router network.


R7 and R8 are connected via Serial 1/0 and in the 78.78.78.0 /24 network.


R7 has a loopback 77 with 77.7.77.77.77 255.255.255.255
R8 has a loopback 88 with 88.88.88.88 255.255.255.255.


What network are these addresses in and what should be their WILDCARD Masks?


Should "no auto-summary" be used here?

Change the 255s to all 0s That means one and only one host

You don't really need the wildcard mask, but if you use it the syntax is 0.0.0.31 (this is an example for the /27 CIDR notation)

Yes on the no auto summary

Here's a quick primer

255.255.255|.0 The 3 255s define the network and the 0 defines the number of hosts in the network.. Since this is commonly called a Class C network, you can have 1 network with up to 254 hosts

Let's say your subnet mask is 255.255.255.192 On this you can have 4 networks with up to 62 hosts per network. So each network could be one for Sales, one for Engineering, one for HR, etc