When the NAT command is used with the special number 0 this tells the PIX not to NAT any of the traffic. In it's most basic form you cna just do:
nat (inside) 0 0 0
The first 0 says don't NAT the traffic, the second two zeroes define the subnet/mask of the traffic to NAT. If you want to get more specific then you can do something like this (assuming you'r inside network is 126.96.36.199/8):
nat (inside) 0 188.8.131.52 255.0.0.0
Then only traffic from the 184.108.40.206 network will not be NAT'd. When using "nat 0" you don't need a corresponding global statement cause the whole point of it is that the addresses aren't changed to something else. You cna also do:
nat (inside) 0 access-list nonat
access-list nonat permit ip 220.127.116.11 255.0.0.0 any
This is primarily used for VPN traffic where you don't want to NAT it as it goes through, but is just as valid for any other traffic also.
The PIX requires that you create translations across interfaces in order for traffic to pass. So, in essence, there is no option to not use NAT in some form. As Glenn pointed out though, you can configure the PIX to NAT the source address back to the same address as it passed from inside to outside. In practice, this gives you the same results as not NAT'ing the traffio on the PIX as the outside hosts will see the original source address on this packet.
DocumentationCode download linksGoalRequirementLimitationsSupported ISR
and UCS-E ModelSupported ISRG2 and UCS-E Blades:Supported ISR4K and
UCS-E Blades:Step by Step ConfigurationConfigure one of the connectivity
options to access the Cisco IMC from the n...
Firepower Threat Defense (NGFWv) on UCS E-series - Transparent Mode in
HA DocumentationCode download linksGoalRequirementLimitationsSupported
ISR and UCS-E ModelSupported ISRG2 and UCS-E Blades:Supported ISR4K and
UCS-E Blades:Step by Step ConfigurationCo...
Question I am currently unable to specify "crypto keyring" command when
configuring VPN connection on my cisco 2901 router. The following
licenses have been activated on my router :