CISCO 1812 can see the internet, but clients can't, outside internet can't

Posted on 2006-04-26
Last Modified: 2010-04-17
very new to cisco routers here, so i'll try as best that i can..

our network now:
older router = 38.154.x.1
older router =

the network'd comptuers are connected to the old router with the 192.168.10.x ip range

we just installed a Cisco 1812 router, just configured it using the SDM express program....

FastEthernet (outside) IP 38.154.x.2

Vlan1 (inside) IP

Routing: 38.154.x.1

client machine = /
client gw =

the client can't see the internet.
the outside internet computers can't see the router
however, the cisco router can ping internet sites / servers.

any help here?  need more information? please let me know

Question by:Eric
    LVL 28

    Expert Comment

    So you are trying to swap out the router so that you're only using the new one, or you're trying to tie them together? You have the default route 38.154.x.1, which points to the IP of the old router. It needs to point to the ISP's address.
    LVL 6

    Author Comment

    we are eventually swapping routers and replacing the old one. but for now, i am trying to set them parallel to each other...   we have a full class c from our ISP, so testing shouldn't be a problem.
    LVL 28

    Expert Comment

    How are they being connected in parallel? Can you provide:
    1. Configs, with passwords removed and public IPs masked as you did above
    2. A picture showing devices and how they connect in a simple way, such as

    Vlan1-1812 -F0/0---
                              DLink router--- ISP
    old router-----------

    Or however they are connected. Then I can look and ask more questions.
    LVL 12

    Expert Comment

    What is the /24 network from the ISP?  ("class C" is the old term that should not be used any longer)
    What is the configuration on the router?  SDM is great (I guess), but many of us use the CLI 100% of the time.
    LVL 3

    Expert Comment

    What can the clients ping of the below?
    LVL 15

    Expert Comment

    If you configured using the sdm express and did not enable the firewall, this makes sense. telnet to the router and tye "show running-config" and look for these lines;

    ip inspect name SDM-LOW tcp
    ip inspect name SDM-LOW udp

    interface vlan1
    ip inspect SDM-LOW out

    for a good demo of the SDM express go to

    LVL 6

    Author Comment

    I got the router to see the internet.

    ping results:  = success 5/5
    38.154.x.2 = failure 0/5 (umm.. this is the external ip of the router, it should be pinging it, shouldn't it ?)
    38.154.x.1 = success 5/5 = success 5/5 = failure 0/5 = success 5/5
    66.42.x.84 (remote location) = success 5/5 (the client i have connected to the router for confuration) = failure 0/5

    Accepted Solution

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