Moses,

Using the wild card mask is more granular and comes handy if you do not want to include all interfaces that fall into the network you specify. If all interfaces have to be included anyway, you could just use the network statement without the wild card mask.

Hope this helps,

The wildcard mask specified along with the EIGRP network statements allows granularity in selecting the interfaces where you want EIGRP to run.

By default EIGRP assumes the major classful network when you do not use the wildcard mask.

for eg, if you have a router with 2 interfaces with ip addresses

10.10.10.1/30 and 10.10.10.5/30 respectively, without the wildcard mask with the networl statement 10.10.10.0 would start eigrp on botn the interfaces. if you want only one of the interfaces to run eigrp, you would require a subnet mask to be configured

router eigrp 100

network 10.10.10.0 0.0.0.3

The above statement starts eigrp only the interface with the subnet 10.10.10.0/30 and not on the 10.10.10.4/30

HTH, rate if it does

Narayan