7206 VXR at Home

[Grant Curell]

Hello Everyone!

I just spent the last several hours trying to figure this one out yet the answer elludes me. I bought a cisco 7206 VXR off of ebay and am trying to set it up to replace my standard linksys router at home. The 7206 is connected via ethernet straight through cable from its fa0/0 port to the modem. The modem confirms the connection with a flashing amber light (indicating that the connected device is 10/100 speed).

Here's the part that boggles my mind, when I try to set up the 7206 as a DHCP client it will not acquire an IP address.

Troubleshooting and Tests Performed so Far:

1) Plug the 7206 into the back of my Linksys router. Perform a renew dhcp fa0/0. This works! It acquires an address properly.

2) Set a static IP of 192.168.100.2 on the fa0/0 interface and use a laptop connected into fa0/1 to connect to the modem at 192.168.100.1 to confirm connectivity. This works!

3) Statically set the ip address, mask, and default gateway on fa0/0 to exactly the same settings that were acquired by my laptop via DHCP to see if I manually config everything changes anything. Does not work! I am unable to ping the ISP's default gateway.

4) I have also tried release dhcp fa0/0 and renew dhcp fa0/0 to see if cycling things works.

5) Checked the WAN settings on my linksys router just to see if there was anything non-standard. Uses the default DHCP over ethernet configuration.

The DHCP client obviously works on the linksys router. What am I missing when I'm plugging it into my modem? What is the difference between the two?

Grant

[Grant Curell]

Ok, so I've gotten a bit closer. I added the command "duplex full" to the fa0/0 interface. For some reason that at least got me the following output:

I saw on a forum that someone suggested using a crossover cable between the modem and the router. The router is old enough that I discovered it does not have autosense. Could this be a legitimate solution? If so, why? Unrelated does this output provide further insight into the problem? I haven't had the chance to go investigate the DHCP protocol to determine the specifics of this new error message.

[Joseph W. Doherty]

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The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

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Posting

The router's ports probably don't have auto MDI/MDI-X, but your cable modem may have that.  The fact your 7200 can decode packets seen on the interface connected to the cable modem should mean you have a good connection.  On the 7200, show interface shows up/up?

[Grant Curell]

Yes, it does show up and up.

[Joseph W. Doherty]

Disclaimer

The  Author of this posting offers the information contained within this  posting without consideration and with the reader's understanding that  there's no implied or expressed suitability or fitness for any purpose.  Information provided is for informational purposes only and should not  be construed as rendering professional advice of any kind. Usage of this  posting's information is solely at reader's own risk.

Liability Disclaimer

In  no event shall Author be liable for any damages whatsoever (including,  without limitation, damages for loss of use, data or profit) arising out  of the use or inability to use the posting's information even if Author  has been advised of the possibility of such damage.

Posting

#2 is interesting!  By default, usually routers don't like multiple interfaces on the same subnet.  It would be helpful if you would post your config.

PS:

BTW, earlier IOS/platforms did not support DHCP for the device itself.  Posting what's your NPE and IOS version would also be helpful.

Likely, though, your 7200 will support providing DHCP addresses to clients - does require configuration.

[Grant Curell]

I just used a different subnet on the fa0/1 interface and had all the traffic forwarded via a default route if I remember from yesterday correctly. (I was trying a lot of different things lol). The output of show version is below, the OS is the most recent version I think. Not sure about the NPE still learning on that one (it's an NPE400, but haven't looked up how recent that is):

    The configuration is attached.

[Grant Curell]

If the router didn't support becoming a client itself then it wouldn't have worked when I used the linksys router as a DHCP server and used the 7206VXR as the client would it? Since it did work I assumed that the router did support becoming a client.

[Joseph W. Doherty · Accepted solution]

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

Ok, rereading your OP, and looking over your config, the problem you might be having, provider modems will often only provide a DHCP lease to single host.  For such, when you connect a different host, you need to power cycle the modem.  (This might also explain the DHCP messages "Not for us")

BTW, regarding your config, I believe the default route statement will support some DHCP option, i.e. so you don't have to hard code the next hop.

[Grant Curell]

I haven't tried rebooting the router now that I've added the "duplex full" command. I'll try cycling the modem and report the results when I'm home next (the 16th ). I'd assume you're right about the default route. That was left over from when I tried hard coding the settings. Thanks for the tips by the way :-D - much appreciated. I'll get back to you the 16th when I'm home next.

[Grant Curell]

You were right... O.o. After all that work I just had to power cycle the modem, which is interesting because I didn't have to power cycle it when I swapped out a laptop for the regular linksys router. Anyway, got it all up and running ;-D

[Joseph W. Doherty]

Thanks for lettting us know that resolved your issue.