172.31.0.0 /24 is subnetted............

shanparames

Hi

In ICND2 I have found this theory in one example for show ip route.....Gateway of last resort is not set, 172.31.0.0 /24 is subnetted , 10 subnets and it is giving the subnets as 1. 172.31.130.0 .172.31.140.0,..........

What is my confusion is 172.31.0.0 /24 is subnetted means the subnetting should start after 24 bits .? the subnets are in 3rd octet ..

May be I am wrong in my interpretation ! Please anybody kindly explain this

Thanks & Regards

S.Swaminathan

drkat

You shall find what you seek in show run | i ip route

kurosaki00

/24 = 11111111.11111111.11111111.00000000
172 = B
meaning class B, but you have used all first 3 octects, meaning only your final octect is available for addresses

Also, 172.31 is a private IP, so careful how you use it

Darthn3ss

I'm probably going to go and make a fool of myself here one way or another, but I'm pretty sure the /24 is the longest mask that describes all of the subnets-a summary. But i may be very wrong. Please correct me if so.

oli356

Darthn3ss wrote: »

I'm probably going to go and make a fool of myself here one way or another, but I'm pretty sure the /24 is the longest mask that describes all of the subnets-a summary. But i may be very wrong. Please correct me if so.

Well you can go further then /24 for example /29 so 255.255.255.248.
6 hosts, 32 subnets (think that is right.. im tired and doing it in my head lol)

shanparames

Thanks for all who replied