Technical issues on NAT

[Mohamed Kabeer S]

Hi all,

I am kabeer,I have configured Cisco 1841 router PAT buts its not worked please find the below configuration details,

In LAN  interface

Interface gigabit Ethernet 0/0

no shutdown

Ip address 192.168.1.1 255.255.255.0

Ip nat inside

Exit

In wan interface

Interface gigabit Ethernet 0/1

No shutdown

Ip address 202.100.x.x 255.255.x.x

Ip nat outside

Exit

Access-list 1 permit 192.168.1.0 0.0.0.255

Ip nat inside source list 1 interface gigabit Ethernet 0/1 overload

Similarly I have configured static and dynamic nat but its not works in my customer place.

So kindly provide the solution for this issue.

Thanks and Regards,

Kabeer

[cadet alain]

Hi,

NAT is done after routing so if routing is not working your NAT won't either.

can you post output of sh ip route | i 0.0.0.0

Regards

Alain

Don't forget to rate helpful posts.

[Mohamed Kabeer S]

Hi cadet,

I have configured default-route to 202.100.x.x address.but its show the route but PAT not working.

So kindly provide the solution for this.

I am waiting for your reply.

Regards,

kabeer

[johnlloyd_13]

hi,

are you sure this is an 1841? usually they're FE ports.

also, are you able to ping the ISP or any public IP (8.8.8.8).

kindly post router config and hide sensitive info.

[Mohamed Kabeer S]

Hi,

This is 1841 router,above mentioned configuration are configured manually,Its FE port because in client place only I am  configured PAT in 1841 router but Its not working,I am searching all forums and video tutorial the commands I have entered are correct but its not worked.I have connected isp cable directed to my laptop and Its working then I have connected to my 1841 router,I am able to ping public ip (8.8.8.8) through my router 1841  and through my laptop dirctly connected to 1841 FE0/0(LAN interface ) but its not working.I put extended ping command fron LAN interface to WAN but its not ping wan interface.please find the below configuration details of 1841 router.

Router#show running-config
Building configuration...

Current configuration : 726 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/0
description ####LAN####
ip address 192.168.1.1 255.255.255.0
ip nat inside
duplex auto
speed auto
!
interface FastEthernet0/1
description ####WAN####
ip address 202.100.x.x 255.255.x.x
ip nat outside
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip nat inside source list 1 interface FastEthernet0/1 overload
ip classless
ip route 0.0.0.0 0.0.0.0 202.100.x.x
!
!
access-list 1 permit 192.168.1.0 0.0.0.255
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end

So kindly provide solution for this issues.

regards

kabeer

[johnlloyd_13]

hi,

you NAT config is ok and ISP connectivity looks fine.

try to update the IOS.

[paul driver]

Hello

int vlan 1
No shut

res
paul


Sent from Cisco Technical Support Android App

[Mohamed Kabeer S]

hi,

pls find the below IOS details of 1841 router

Router#show version
Cisco IOS Software, 1841 Software (C1841-IPBASE-M), Version 15.0(1)M3, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2010 by Cisco Systems, Inc.
Compiled Sun 18-Jul-10 01:16 by prod_rel_team

ROM: System Bootstrap, Version 12.4(13r)T, RELEASE SOFTWARE (fc1)

Router uptime is 19 minutes
System returned to ROM by power-on
System image file is "flash:c1841-ipbase-mz.150-1.M3.bin"
Last reload type: Normal Reload

Cisco 1841 (revision 7.0) with 235520K/26624K bytes of memory.
Processor board ID FHK144075RH
2 FastEthernet interfaces
DRAM configuration is 64 bits wide with parity disabled.
191K bytes of NVRAM.
62720K bytes of ATA CompactFlash (Read/Write)

License Info:

License UDI:

-------------------------------------------------
Device#   PID                   SN
-------------------------------------------------
*0        CISCO1841             FHK144075RH

Configuration register is 0x2102

Regards,

kabeer.

[Mohamed Kabeer S]

Hi all,

Kindly post a solution for my issues.I am waiting for anyone response.

Regards,

kabeer

[Bilal Nawaz]

Asalaam Kabeer, did you manage to solve this one?

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[Mohamed Kabeer S]

va alikum assalam bilal,

thanks for your response.

No bilal.I can,t able to find the exact solution for this issues.pls see above conversation for this issues.

[Bilal Nawaz]

Are you able to ping your default-gateway from the router to the 202.x.x.x address? Also, how are clients getting their addresses? If it is DHCP please make sure that the default-router address for DHCP is 192.168.1.1

Or try to plug in a laptop/PC with an IP of 192.168.1.2 mask of 255.255.255.0 and default gateway of 192.168.1.1 and then see if it works.

1. First check if you can ping the LAN interface of the router
2. Check if you can ping WAN interface of router
3. Check if you can get past the WAN interface to the internet or something

You should be able to see NAT translations if this is working. 'show ip nat translation'

Hope this helps

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[Mohamed Kabeer S]

Hi billal,

thanks for your response,

i have done everything.I just connect my laptop directly to that lan interface on router.From my pc i am able to ping lan interface and wan interface.but i can't able to ping gateway.i have configured one-to-one nat,dynamic nat and pat but configuration are done but nat translation is not working.Is there any bucks in ios?If i update ios which ios are preferrable for this router.

regards

kabeer

[Bilal Nawaz]

Kabeer, Can we try pinging the gateway from the router itself please?

Please provide the output of 'show ip route' and 'show run'

Thank you

Please rate useful posts and remember to mark any solved questions as answered. Thank you.

[Mohamed Kabeer S]

Hi billal,

I can't able to ping the gateway from the router.I am dirctly connected ISP lease line to my laptop internet is working.

Router#show ip route
Codes: C - connected, S - static, I - IGRP, R - RIP, M - mobile, B - BGP
       D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
       N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
       E1 - OSPF external type 1, E2 - OSPF external type 2, E - EGP
       i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS level-2, ia - IS-IS inter area
       * - candidate default, U - per-user static route, o - ODR
       P - periodic downloaded static route

Gateway of last resort is 202.200.x.x to network 0.0.0.0

C    192.168.1.0/24 is directly connected, FastEthernet0/0
C    202.200.x.x/24 is directly connected, FastEthernet0/1
S*   0.0.0.0/0 [1/0] via 202.200.x.x

Router#show running-config
Building configuration...

Current configuration : 726 bytes
!
version 12.4
no service timestamps log datetime msec
no service timestamps debug datetime msec
no service password-encryption
!
hostname Router
!
!
!
!
!
!
!
!
!
!
!
!
!
!
spanning-tree mode pvst
!
!
!
!
interface FastEthernet0/0
description ####LAN####
ip address 192.168.1.1 255.255.255.0
ip nat inside
duplex auto
speed auto
!
interface FastEthernet0/1
description ####WAN####
ip address 202.100.x.x 255.255.x.x
ip nat outside
duplex auto
speed auto
!
interface Vlan1
no ip address
shutdown
!
ip nat inside source list 1 interface FastEthernet0/1 overload
ip classless
ip route 0.0.0.0 0.0.0.0 202.100.x.x
!
!
access-list 1 permit 192.168.1.0 0.0.0.255
!
!
!
!
!
line con 0
line vty 0 4
login
!
!
!
end