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DHCP Activity Logging

Is there any way to make a Cisco 831 router log DHCP changes from the provider?

I'm seeing some weird things. Sometimes, I discover I'm getting a 192.168.#.# address instead of a public IP address. I've discussed it with Mediacom, but they don't believe me. When I get a private IP address on the provider interface, I am unable to use the Internet for some strange reason. Since I have VOIP at home, that's a problem (no phone service when this happens).

If I could dump DHCP activity to a file on my TFTP server, I could keep it and provide it to Mediacom so perhaps I could get them to fix this.

Regards,

Fred

Reply to
Fred Atkinson
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Hi Fred,

What you could do - you can turn on the debug information for the DHCP client. It will log everything related to a DHCP activity. Here is a link to the Cisco.com website with some information:

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You may install the Syslog server on your PC (or any PC which is always on), and send all log activity to that PC. If you do not have your PC always on, you can log to internal router's buffer, and check it daily, if you have anything.

Good luck,

Mike

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Reply to
CiscoHeadsetAdapter.com

Mike,

Sounds like a plan. I've turned on the debug dhcp option. I'm searching for a free syslog server but so far have been unable to locate one.

Any suggestions?

Thanks very much, sir.

Fred

Reply to
Fred Atkinson

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Reply to
DoubleD4

kiwi

3CDaemon from 3Com
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Reply to
Hansang Bae

I've installed the KIWI syslog server. It doesn't seem to be receiving the DHCP activity. I used the 'release dhcp e1' and waited for the activity to finish. Then I used the 'renew dhcp e1' and waited again.

No activity registered on the KIWI server.

I'm suspecting that I need to enter a Cisco command into the

831 to make it send to the KIWI server. Fortunately, my PC has a static IP address.

Regards,

Fred

Reply to
Fred Atkinson

Fred,

Check you router configuration. You should have logging to the host (syslog).

logging host logging trap

You may change the "facility" for your messages, but it should work even without it.

logging facility

To check avalable options you can always enter "?" after the command.

You can always check how and where you send your Syslog messages by typing the "show log" command - first section will show you logging status.

Another thing - sometimes Kiwi Syslog just does not work. Try to stop/start it a couple times.

Good luck,

Mike

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Reply to
CiscoHeadsetAdapter.com

That's pretty close to what I had in there already. I re-entered them, however. I'm getting the same results, no messages. Shouldn't it log when I release and renew the e1 interface? It doesn't.

Weird.

Fred

Reply to
Fred Atkinson

Well,

I've let the syslog server run for a few days. It has some error messages, but it doesn't show any DHCP activity from my router. Still confused.

Fred

Reply to
Fred Atkinson

exactly what debug commands where entered ?

I believe for the router as a DHCP client "debug dhcp detail" would be the one to use

Reply to
Merv

I put yours in. Then I released and renewed the lease. The actions never logged on the syslog server, either.

What I want to track is what the IP address changes are. I am getting some entries, but only that the interface is up or down. There is no reference to changes in the IP address.

Regards,

Fred

Reply to
Fred Atkinson

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