Pix515E with CIDR , please help

[sean chang]

Hi,Everyone,

we just acquired a new pix 515E with PIX version 6.3(5), PDM 3.0. I got 16 IP from COX , which is CIDR 70.183.141.192/28, after I configure Inside/outside interface, the networking is working, the problem is with it can't acquire any other addresses. I.E, I used 70.183.141.193 as outside gateway, the networking works fine, but I can't use NAT to configure an internal PC to use this address: 70.183.141.194; if I reset the pix 515E and use 70.183.141.194 as the outside IP, then I can use 70.183.141.193 for NAT , but if I don't use it for another 2 Hours, the address 193 is lost again and I need re-initinize it by resetting the firewall using it as outside IP and then change to another IP to make it visible again...

sorry about the long description, my questions are:

1. Does Pix version 6.3(5) from pix515E support CIDR address? I got another one working with class C address is perfectly fine.

2. If yes, what did I configure wrong? if not , what should I do to make it recognize all 13 usable addresses?

Any suggestions are greatly appreciated.

sean chang

[dominic.caron · Accepted solution]

Pix support CIDR, I use a /28 on my outside production network. As for what is wrong, it would help if you could paste your config.

[sean chang]

Thank you for the reply. It turned out a problem with COX CIDR configuration, not Firewall problem, but still a lot thanks.