Confused with redistribute subnet keyword

[mirror512]

I am not able to fully understood how does subnet keyword works.

What wiull happen , if i don't use that.

IN some question the author says that there is no subnet keyword for EIGRP . Is that true

[Jon Marshall · Accepted solution]

redistribute subnets is used in OSPF so no EIGRP does not have it.

What it does is redistribute subnets as well as classful networks. So lets say you have 4 networks -

172.16.0.0/16  <-- this is a classful route

172.16.5.0/24 - this is a subnet of the classful 172.16.0.0/16 network

192.168.5.0/24 <-- this is classful

192.168.6.128/25 <-- this is a subnet of the classful network 192.168.6.0/24

so without subnets only 172.16.0.0/16 and 192.168.5.0/24 will be redistributed into OSPF.  If you use the subnets keyword then all 4 subnets will be redistributed into OSPF.

Jon