NAT in 2650s

[mukundh86]

Hello all,

I have the following configs for NAT in a Cisco2650XM:

ip nat inside source route-map nonat interface Serial0/0 overload

route-map nonat permit 10

match ip address nonat

ip access-list extended nonat

permit 192.168.85.0 0.0.0.255 any

interface FastEthernet0/0

ip address 192.168.85.1 255.255.255.0

ip nat inside

int ser0/0

ip address 1.1.1.1 255.255.255.0

ip nat outside

When i do "ping 4.2.2.2 source fa0/0", it is not successful.

The same configs are  applied  on a Cisco IAD 2431 nd the pings are successful.

Any reason as to why this difference is there?

Thanks

Mukundh

[johnlloyd_13]

hi mukundh,

have you configured a static default route on your 2650?

please post full config and topology map.

[mukundh86]

Hi John

I dont have access to the router now. But apart from the configs I stated, the only other important line I could think about is the static default route as follows:

ip route 0.0.0.0 0.0.0.0 1.1.1.2

There are no other static routes or dynamic routing involved.

Thanks

Mukundh

[johnlloyd_13]

ok. is this a lab set up?

were you able to ping 1.1.1.2 from this router?

[mukundh86]

Yes, it is a lba setup

I was able to ping 1.1.1.2 when i just enter "ping 1.1.1.2" in global mode but when i enter " ping 1.1.1.2 source fa0/0" there is no success.

[johnlloyd_13]

ok gotcha but i still need to see your full config and topology diagram.

make sure your 2650 FE0/0 is up/up.

also, kindly re-configure NAT and try again:

2650XM(config)#ip nat inside source list nonat interface serial 0/0 overload

[jas2061461]

• Trying using "ping 1.1.1.2 source 192.168.85.1".
• Use "show ip nat translations" to verify that it was translated.
• If this does not work, simply your configuration in all ways.
• First, take out the route-map; just use the ACL.
• Try "ip route 0.0.0.0 0.0.0.0 serial 0/0".
• I am assuming this is a GNS3 lab.  If this is an actual setup, you may want to set serial0/0 to "ip address DHCP".
• If it is a GNS3 lab, make sure you can ping 4.2.2.2 before you use NAT.
• Always make sure there is a route back to the source.

This should help a bit.  Good luck!

[ebarticel]

You need to apply the policy map to fastethernet interface

ip policy route-map nonat

Hope this helps

Eugen

[mukundh86]

Hi all,

There seems to be an IOS related bug. For some IOSes in 2650s natting for the ip address of fastethernet interface or LAN  interface doesnot take place.

Thanks all for your help!!!!

Mkundh