NAT? 1

[ar123]

I have a main store that has 5 branches which are connected using frame-relay. Each has a cisco 1750 router with their own subnet. At the main store we have a DSL router on the ethernet. We can use the internet fine in the main store but how can we get the branches to be able to use it? Must we enable NAT on the cisco routers? NAT is already enabled on the DSL router. Any input would be most helpful.

 

[svermill]

Without knowing your exact config, I suspect that you need an 'ip nat inside' statement on the frame relay subinterfaces so that your remote sites can be translated into your public address or range of addresses.

 

[scraig84]

Typically you only really want to do NAT once in the organization. My guess is that you don't have default routes everywhere or they are not configured correctly. Typically, the default path should eventually lead packets to the Internet router. This either has not been done or they routes point to a different network rather than out of the organization.

 

[svermill]

scraig84 is correct that NAT should only be implemented once. I didn't read carefully enough that the DSL router was the one doing the NAT. Don't know a lot about DSL routers. Does your NAT config cover the address space that is coming in from the remote sites? If so, then scaig84 has some good advice for you regarding default routes.

 

[jeter]

Because the dsl is on the LAN side of the host I would insert a gateway of last resort. If the internet was coming off a sub-int on the router, I would use NAT. “Reserve your right to think, for even to think wrongly is better than not to think at all”

Fisher CCNA,(CCNP-Routing)
UOP Student BSIT

 

[ar123]

I appreciate everybody's help -

I have one more question - how do insert a gateway of last resort? Is the command ip route 0.0.0.0 0.0.0.0 (ip of the dsl router) Would this work? Or would we need to put ip default-network?

Thanks again for everyone's help. It is truly appreciated!

 

[scraig84]

The ip route command is the correct one.

 

[CCIEWANNABE]

0.0.0.0 0.0.0.0 is used with IGRP and EIGRP
0.0.0.0 is used with RIP

Your Internet gateway is always a good default route to pick.

IE: ip route 0.0.0.0 0.0.0.0 {gateway IP ADDRESS)
Route once; switch many

 

[Guest_imported]

I have 2 private adress from ISP
and one adresse LAN
and DLCI
it is Frame Replay IETF

how can i connect to the Internet

 

[jeter]

Here is a sample config!



interface Serial0
no ip address
no ip directed-broadcast
encapsulation frame-relay IETF
no fair-queue
service-module t1 timeslots 1-8 <-- For a 512K circuit
frame-relay lmi-type ansi
!
interface Serial0.1 point-to-point
description circuit# 60.QBDA.XXXXX FRAME RELAY TO INTERNET
ip address 205.25.225.106 255.255.255.252
no ip directed-broadcast
frame-relay interface-dlci 17
!
interface FastEthernet0
ip address 206.159.183.217 255.255.255.248
no ip directed-broadcast
half-duplex
!
ip classless
ip route 0.0.0.0 0.0.0.0 205.25.225.105 <-Far end ip add
ip http server “Reserve your right to think, for even to think wrongly is better than not to think at all”

Fisher CCNA