Cisco 851 Newbie Help Please!

We just bought a Cisco 851 Router for the office to replace a failing D-
Link GamerLounge.

I got all of the configuration done (I thought!) through the web interface,
but it will not route connections to the WAN. I verfied that the DNS server
and T1 line are working fine by direct connection.

The following things are plugged into our 851:
- WAN Port: T1 line with static IP
- Crossover cable connecting to our main switch
- Our server
- Our backup system

The network part works fine. I can ping everybody, and I can VNC to our
server. The Internet, however, doesn't work.

I think it has to do with the fact that the 851 doesn't know how to contact
our ISP's router. There doesn't appear to be any place to input a value for
"default gateway." I tried putting the IP we have for the gateway into the
"last hop" section, but I didn't know if it should be done by interface or
by IP.

Any suggestions? I'm not really an IT guy, but I know the most about IT at
the company, so...


Thanks!

Steven Smith

Hi Steve,

> I think it has to do with the fact that the 851 doesn't know how to contact
> our ISP's router. There doesn't appear to be any place to input a value for
> "default gateway."

We really need a lot more info here, such a full configuration dump of
the Router, however a first VERY rough guess is that you need to
specify a DEFAULT GATEWAY. If you can see the full Router
configuration, then look for a line that looks like -

ip route 0.0.0.0 0.0.0.0 <next hop address>

where <next hop address> specifies your ISP's Router IP address.
0.0.0.0 0.0.0.0 specifies the DEFAULT Gateway.

> I tried putting the IP we have for the gateway into the
> "last hop" section, but I didn't know if it should be done by interface or
> by IP.

99% of the time by IP address. There are some situations where an
interface can be used but they are fairly specific.

Cheers..................................pk.

--
Peter from Auckland.

Hi Peter,

Thanks for the advice so far.

I think that the problem IS that the default gateway isn't defined; I
just can't seem to figure out where I need to define it! Is there a
console command I should use, or is there a way to do it through the GUI?

When I went to the tab where you define the connection type
(static/dhcp), I was able to input our IP and netmask, but I didn't see
the usual "default gateway" option. I wondered how it could possibly
work without one, but figured if it were needed, it would be there...

Our external IP is 64.80.9.45, and the ISP's default gateway is
64.80.9.1. Could I telnet into the router and just type:

ip route 0.0.0.0 0.0.0.0 64.80.9.1

Would that work? Or does the 64.80.9.1 need to be .45?


I knew I should have taken those CCNA classes....




"Peter" <(E-Mail Removed)> wrote in
news:nnw7edSM2ZOu-pn2-dsRIrKRklN8N@otis:

> Hi Steve,
>
>> I think it has to do with the fact that the 851 doesn't know how to
>> contact our ISP's router. There doesn't appear to be any place to
>> input a value for "default gateway."
>
> We really need a lot more info here, such a full configuration dump of
> the Router, however a first VERY rough guess is that you need to
> specify a DEFAULT GATEWAY. If you can see the full Router
> configuration, then look for a line that looks like -
>
> ip route 0.0.0.0 0.0.0.0 <next hop address>
>
> where <next hop address> specifies your ISP's Router IP address.
> 0.0.0.0 0.0.0.0 specifies the DEFAULT Gateway.
>
>> I tried putting the IP we have for the gateway into the
>> "last hop" section, but I didn't know if it should be done by
>> interface or by IP.
>
> 99% of the time by IP address. There are some situations where an
> interface can be used but they are fairly specific.
>
> Cheers..................................pk.
>

Hi Steven,

> I think that the problem IS that the default gateway isn't defined; I
> just can't seem to figure out where I need to define it! Is there a
> console command I should use, or is there a way to do it through the GUI?

I dont use the Cisco GUI at all so I cant say.....;-) However if you
can get into the console ENABLE mode you should end up at a
<routername>#
prompt. From there you can type
show run
to display the full running configuration (careful about posting that
raw here, it may contain sensitive password info etc... ).

Look for lines such as -
<routername># ip route x.x.x.x y.y.y.y d.d.d.d
If x & y = 0.0.0.0 then thats the default gateway.

If there is no such line there, then type =
<routername># config terminal
<routername>-confg# ip route 0.0.0.0 0.0.0.0 64.80.9.1
<routername>-confg# exit
<routername>-confg# copy run start

This adds the defautl gateway , the exits configure mode and saves the
changes to the startup configuration file.

> Our external IP is 64.80.9.45, and the ISP's default gateway is
> 64.80.9.1. Could I telnet into the router and just type:
>
> ip route 0.0.0.0 0.0.0.0 64.80.9.1
>
> Would that work? Or does the 64.80.9.1 need to be .45?

No it should NOT be YOUR IP address. What MASK value is being used on
that interface, that may be a clue.

Good luck....................pk.

--
Peter from Auckland.

Peter-

It works! Thanks!

-Steven


"Peter" <(E-Mail Removed)> wrote in
news:nnw7edSM2ZOu-pn2-fzywxxn6I7Ff@otis:

> Hi Steven,
>
>> I think that the problem IS that the default gateway isn't defined; I
>> just can't seem to figure out where I need to define it! Is there a
>> console command I should use, or is there a way to do it through the
>> GUI?
>
> I dont use the Cisco GUI at all so I cant say.....;-) However if you
> can get into the console ENABLE mode you should end up at a
> <routername>#
> prompt. From there you can type
> show run
> to display the full running configuration (careful about posting that
> raw here, it may contain sensitive password info etc... ).
>
> Look for lines such as -
> <routername># ip route x.x.x.x y.y.y.y d.d.d.d
> If x & y = 0.0.0.0 then thats the default gateway.
>
> If there is no such line there, then type =
> <routername># config terminal
> <routername>-confg# ip route 0.0.0.0 0.0.0.0 64.80.9.1
> <routername>-confg# exit
> <routername>-confg# copy run start
>
> This adds the defautl gateway , the exits configure mode and saves the
> changes to the startup configuration file.
>
>> Our external IP is 64.80.9.45, and the ISP's default gateway is
>> 64.80.9.1. Could I telnet into the router and just type:
>>
>> ip route 0.0.0.0 0.0.0.0 64.80.9.1
>>
>> Would that work? Or does the 64.80.9.1 need to be .45?
>
> No it should NOT be YOUR IP address. What MASK value is being used on
> that interface, that may be a clue.
>
> Good luck....................pk.
>