Subnetting 2 x /30 IPs

[Mokhalil82]

Hi

In my studies I remember learning when assigning IP addresses to a network we need to break the network down into subnets and find out how many IP's required for each subnet, then we subnet an address starting with the highest number working down to the /30's.

So now I am installing a firewall and a router at a DR site and need 2 /30 subnets. My question is can i subnet at any point in an IP range for example

The client uses a 172.50.250.0/25 so address range is .0 to .127

Then another subnet 172.50.250.128/30 so address range .128 to .131

Then another subnet 172.50.250.144/29 so address range .144 to 151

So all the address from .132 to .143 are not being used, Can I just use 2 x /30 subnets from this unused range such as 

172.50.250.132/30

172.50.250.136/30

Thanks

Thanks

[Reza Sharifi · Accepted solution]

Hi,

Yes you can. As long as the other leg of the /25 (129-254) is not used anywhere else you can break it down to /30s or 29s, etc..

HTH