Score:0

"AWS CIDR is not within the CIDR ranges of VPC", but it is?

th flag

many questions on this, but this time doesn't seem as obvious as the others.

I'm trying to split a VPC in two subnets.

I start with VPC 10.0.0.0/24, 254+1 IPs, from 10.0.0.1 to 10.0.0.255

I create the first subnet with 10.0.0.0/25, which should reserve one 0 bit of the address. Gives me 126+1 IPs from 10.0.0.1 to 10.0.0.127. Works fine.

The next subnet i try 10.0.0.128/25, which is the same as before but reserving the 1 bit instead. Should gives me IPs from 10.0.0.128 to 10.0.0.255. But fails with "not within the CIDR ranges of VPC"... But why isn't it?

vpc: .0 ----------------- .255
sn1: .0 --- .127
sn2:             .128 --- .255
Ron Trunk avatar
in flag
Your subnetting is correct, if that helps.
gabriel avatar
th flag
Thank you. It does help. For now i'm working around this by wasting tons of addresses splitting a /16 into /24s.
Score:1
vn flag

I cannot reproduce your claim:

vpc

subnets

gabriel avatar
th flag
Thank you. Created a new VPC with same values and everything worked. Will just move things to the new one and write this one off as an AWS glitch.
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