NAT using different port numbers

[raymond.burcham]

I have a situation where we are using PAT, but have an application that connects from inside to outside but the return connection uses a different port number. All connections work except this one application.

1) Is the anyway of doing this with PAT

2) If I take the overload command out will, I think will be using NAT and does

NAT care which port the return connection uses. Does it look at ports at all just map address to address.

!

interface Loopback0

ip address 139.170.251.253 255.255.255.128

!

interface FastEthernet0/0

description IRM

ip address 10.10.10.1 255.255.255.128

ip nat inside

duplex auto

speed auto

!

interface Serial0/0

description to Dartmouth

ip unnumbered Loopback0

ip nat outside

encapsulation ppp

no fair-queue

no cdp enable

!

interface FastEthernet0/1

description RES

ip address 139.170.251.1 255.255.255.128

duplex auto

speed auto

!

router rip

redistribute connected

network 10.0.0.0

network 139.170.0.0

!

ip nat pool Dartmouth 139.170.251.129 139.170.251.248 netmask 255.255.255.128

ip nat inside source list 10 pool Dartmouth overload

ip nat inside source static 10.14.12.2 129.170.251.254

ip classless

ip route 0.0.0.0 0.0.0.0 Serial0/0

ip route 10.14.0.0 255.255.128.0 10.10.10.2

ip http server

ip pim bidir-enable

!

access-list 10 deny 10.14.12.2

access-list 10 permit 10.14.0.0 0.0.127.255

!

[tepatel · Accepted solution]

If no "overload" then its simple NAT which will not care for ports. Its inside to outside ip address translation. Here is the link for more on that

http://www.cisco.com/warp/public/556/nat-cisco.shtml

Now for PAT (using overload) to work, the outside to inside reply should be on the same source port number otherwise router will not map those ports correctly.

[raymond.burcham]

Thanks,

Removing the overload did fix their problem.

/ray