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New Member

Configuring PAT as an overflow for several NAT pools created by CSPM.

I am using CSPM to manage the policies on my PIX. I have several class C NAT pools. The problem is that CSPM creates several NAT pools. My questions is can PAT be configured as an overflow for the several NAT pools?

Example below.

nat (inside) 3 192.168.10.0 255.255.255.0 0 0

nat (inside) 2 172.50.38.0 255.255.254.0 0 0

nat (inside) 1 172.50.42.0 255.255.254.0 0 0

global (outside) 1 192.10.128.11-192.10.128.254 netmask 255.255.255.0

global (outside) 2 192.10.129.1-192.10.129.254 netmask 255.255.255.0

global (outside) 3 198.146.129.11-198.146.129.254 netmask 255.255.255.0

4 REPLIES
New Member

Re: Configuring PAT as an overflow for several NAT pools created

PAT can be used as an overflow to a NAT pool; you would simply create further Global entries (1,2 & 3) but only one address would be specified per global entry. Make sure that the address in the new pools don't overlap with those in the existing pools.

You may need to change your existing pools such as:

global (outside) 1 192.10.128.11-192.10.128.253 netmask 255.255.255.0

global (outside) 1 192.10.128.254 netmask 255.255.255.0

In this example the .254 address would be used as the PAT pool

Hope that helps

John

New Member

Re: Configuring PAT as an overflow for several NAT pools created

Thanks

Does NAT start allocating addresses at the beginning of a class C or the end ?

.

New Member

Re: Configuring PAT as an overflow for several NAT pools created

I believe that the pool is used from the lowest address first.

Regards

John

New Member

Re: Configuring PAT as an overflow for several NAT pools created

Yes! Best practise and is a good idea when your hosts is more than IP Addresses declared in your global pool statement. It also saves you IP addresses

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