Solved: Subnetting help - two seperate vlans

ITexpert · ‎04-23-2018

Hello Guys,

My network is working on same vlan now. i have to create vlans and to accomplish that i need to seperate traffic on diff subnets .

Some questions :

1. for example i am using 10.110.16.0/24 subnet for vlan 10 but i have lot of extra IPs and i want to do more subnetting with this subnet and want to use 10.110.16.0/28. Is it possible to use these subnets in separate vlans ?

If yes please explain how to accomplish this ?

Reza Sharifi · ‎04-23-2018

Hi,

Since 10.110.16.0/24 is already being used, you can't take a /28 (10.110.16.0/28) from it and use it somewhere else. You would need to use a different subnet 10.110.17.0/24 or if you want to use 10.110.16.0/24, you would have to stop advertising it, change the mask and readvertise again. Note that this option will cause downtime if this subbed is in production. I recommend you use a completely different subnet and don't mess with the existing one.

HTH

View solution in original post

Reza Sharifi · ‎04-23-2018

Hi,

Since 10.110.16.0/24 is already being used, you can't take a /28 (10.110.16.0/28) from it and use it somewhere else. You would need to use a different subnet 10.110.17.0/24 or if you want to use 10.110.16.0/24, you would have to stop advertising it, change the mask and readvertise again. Note that this option will cause downtime if this subbed is in production. I recommend you use a completely different subnet and don't mess with the existing one.

HTH