nat problem ....!

suhoahn · ‎04-03-2003

hi! I work in ktf .

we have a many cisco platform , catalyst 4006, cisco 7513 ...

we use nat in cisco 7513 . but we have one problem .

let's see our configuration .

ip nat translation timeout 180

ip nat translation tcp-timeout 180

ip nat translation udp-timeout 180

ip nat translation finrst-timeout 180

ip nat translation syn-timeout 180

ip nat translation dns-timeout 61

ip nat translation icmp-timeout 180

ip nat pool KTFWING_1 211.246.0.1 211.246.63.254 netmask 255.255.192.0

ip nat inside source list 1 pool KTFWING_1

dynamic nat is used.

when we see the translation result, we find some problem,

it is that some ip address( local ) translation is PAT !!

why we have seen this result ? I don't understand .

please , give me good consult . thank you .

pbarman · ‎04-04-2003

Do you have any other NAT statements in your config?

wolfrikk · ‎04-04-2003

What is your NAT configuration statements? How many outside IP Addresses are you using for NAT and how many inside IP Addresses is your network using? If you are using the NAT Overload, PAT will be used when the device cannot create any one to one IP Mappings. If you are using 32 external IP Address for NAT, when the 36th Mapping occurs, the device will have to use PAT to make the mapping since it does not have any IP Address available for a true NAT Mapping.

suhoahn · ‎04-06-2003

thank you for answer

we make our public pool to over private address pool .

but , this result is not our mind , '

KURO3F_RT3_C7206#sh ip nat translations

Pro Inside global Inside local Outside local Outside global

--- 211.246.1.53 10.53.13.47 --- ---

--- 211.246.1.54 10.63.3.84 --- ---

--- 211.246.1.55 10.62.2.132 --- ---

--- 211.246.1.56 10.101.46.216 --- ---

tcp 211.246.1.53:1938 10.53.13.47:1938 203.229.191.126:21 .229.191.126:21

tcp 211.246.2.6:2052 10.110.37.230:2052 203.229.191.126:21 203.229.191.126:21

tcp 211.246.2.12:2411 10.53.5.116:2411 203.229.191.126:21 203.229.191.126:21

tcp 211.246.0.1:1216 10.114.49.50:1216 211.115.4.230:21 211.115.4.230:21

look at this result .

211.246.1.53 ip address is mapping 10.53.13.47 , but it is mapping another

ip address !!!

why ? I don't understand . thank you