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New Member

Cisco 867VAE drops connection on DHCP lease timeout

Hey!


We have a very annoying problem on our hands. I'm no IOS expert, but I make do.

We've got a Telia DSL connection that has a 20 minute DHCP lease timer. Every 20 minutes when it shakes hand again, the connection drops for about 5 seconds. This because the Cisco thinks that administratively shutting down the interface is a good idea....


How do I stop this behavior? I've tried manually setting <ip dhcp client lease 1 0 0> (for 1 day lease) but it completely disregards that.


Best would obviously be to stop it shutting down the interface every time, but worst case scenario I'll take a solution with a longer DHCP lease since the address rarely changes.


<snip from log>

*Aug  1 01:44:43.514 PCTime: %DHCP-6-ADDRESS_ASSIGN: Interface ATM0.1 assigned DHCP address 81.230.xxx.xx, mask 255.255.255.0, hostname elsa


*Aug  1 02:04:48.498 PCTime: %DHCP-5-RESTART: Interface ATM0.1 is being restarted by DHCP


*Aug  1 02:04:56.106 PCTime: %DHCP-6-ADDRESS_ASSIGN: Interface ATM0.1 assigned DHCP address 81.230.xxx.xx, mask 255.255.255.0, hostname elsa


*Aug  1 02:25:01.050 PCTime: %DHCP-5-RESTART: Interface ATM0.1 is being restarted by DHCP

</snip>


It's running firmware c860vae-ipbasek9-mz.153-2


I'm attaching the current running-config as well.

Thank you in advance!


Best Regards

Daniel

Everyone's tags (3)
1 ACCEPTED SOLUTION

Accepted Solutions
New Member

About problem of dropping

About problem of dropping connections with DHCP – its our (users) bug not IOS
I found in your config line:
ip nat inside source static 192.168.200.100 interface ATM0.1
All traffic is forwarded to your local server 192.168.200.100 including answers from DHCP server of your internet provider.
DHCP server accept queries on udp port 67 and send answers to client on udp port 68.
You could insert one line:
ip nat inside source static udp 192.168.200.1 68 interface ATM0.1 68
and dhcp answers will go to your router.
Best regards.

 

22 REPLIES
New Member

Cisco 867VAE drops connection on DHCP lease timeout

Still having this problem. Have contacted my ISP about it, but I doubt they'll be able to support me.

I realized that I missed some vital information though:

elsa#show dhcp lease

Temp IP addr: 81.230.xxx.xx  for peer on Interface: ATM0.1

Temp  sub net mask: 255.255.255.0

   DHCP Lease server: 213.66.xxx.xx, state: 7 Renewing

   DHCP transaction id: 22BB

   Lease: 1200 secs,  Renewal: 600 secs,  Rebind: 1050 secs

Temp default-gateway addr: 81.230.xxx.x

   Next timer fires after: 00:00:39

   Retry count: 2   Client-ID: cisco-d48c.b574.7b17-AT0.1

   Client-ID hex dump: 636973636F2D643438632E623532352E

                       376231372E4154302E31

   Hostname: elsa

Through a contact of mine, I got the information that the router should renew the lease before it expires, and the "shutting down port" behavior only happens when the lease really expires. I see that it should update after 600 seconds, but the logs aren't showing anything about this. Only the constant spam of the message in my first post.

Noone got a solution to this?

Thankful for help!

Re: Cisco 867VAE drops connection on DHCP lease timeout

Hello

I can see your cam aging is set to 15 second, why is this? -  Usually tihis his is set to 5mins (300 secs)

Trying removing the requested dhcp client lease command from the atm sub interface and if possible change the cabling.

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.

Please don't forget to rate any posts that have been helpful. Thanks.
New Member

Re: Cisco 867VAE drops connection on DHCP lease timeout

Hey,

I have absolutely no idea about the cam aging, it's the first response to the config I've received so far.

It's nothing I have entered myself - that I know. I'll look it up. You think this can be the cause, or is it just a generic oddity?

Do you mean that I should remove the line "ip dhcp client lease 1 0 0" from ATM0.1?

If so, that line was added after the problem occured and it's already gone again. Power cycled afterwards as well.

The cabling was one of the first things I tried changing, to no avail. And the same cabling is working flawlessly on a Linksys X1000 router atm. I gave up due to our phones kept going down every 20 minutes, because of the Cisco.

New Member

Re: Cisco 867VAE drops connection on DHCP lease timeout

I'm amazed that noone has any ideas about this. Not in a way that I think people Should have and owe me one, but that it's really such a delicate problem.

The guys at Experts Exchange was sadly clueless about this particular issue as well.

Time to actually call Cisco and ask them. My ISP couldn't do anything for me. A normal Linksys X1000 works like a charm. And if my configuration is allright, as it seems to be since noone has commented on it anywhere, the situation is absurd.

I also tried downgrading firmware as well, just in case. Still the same results.

Cisco Employee

Cisco 867VAE drops connection on DHCP lease timeout

Hi Daniel,

Try 15.2(2)T code; there is an enhancement bug,CSCtl51139, fixed in that release. Hope it can help.

HTH,

Lei Tian

New Member

Re: Cisco 867VAE drops connection on DHCP lease timeout

That looks promising, do you mean 15.2.2T(ED)? Looking at the Download Software part for the 867VAE.

Wouldn't it be fixed in 15.3.1T(ED) or 15.3.2T(ED) as well then? The ones I already tried. Or am I thinking incorrectly?

Cisco Employee

Cisco 867VAE drops connection on DHCP lease timeout

Yes, 15.2(2)T(ED). The only way to confirm if a code has the fix is to compare the code. Yes, you are correct, in general if the fix is in 15.2T, I would expect it is fixed in 15.3T as well.

HTH,

Lei Tian

New Member

Re: Cisco 867VAE drops connection on DHCP lease timeout

Just checking in to say that I've got a case open at Cisco. They're setting up a lab environment to replicate the issue.

I will get back with their findings here, if any.

New Member

Cisco 867VAE drops connection on DHCP lease timeout

Hi Daniel,

I am having the same problem with my Cisco 877 router. I am running an older 12.4 code but i was wondering whether Cisco had any feedback on resolving this problem?

thanks

Mario

New Member

Cisco 867VAE drops connection on DHCP lease timeout

I'm sorry for not reporting in. The case is closed at Cisco and they simply couldn't do anything. The router does, according to the debug logs, send dhcp renew requests, but the ISP doesn't reply to them. If they get lost on the way, or if there's an incompatability with the ISP, I dunno. I heavily doubt it, since Telia (Swedish ISP) used Cisco gear for pretty much everything.

Also, Telia will not reply to anything like this, since they don't support equipment they don't supply.

So I'm completely at a loss, and will remain there until I stumble across something.

I've received an 887M router though, which I'm gonna test. But I'm currently stuck with the fact that it's not supported anymore, and therefor I can't seem to download new IOS software (it uses a very old one).

This is the last reply I got before they closed my case:

---------------

*Aug 27 14:56:15.751 PCTime: DHCP Ack Message

*Aug 27 14:56:15.751 PCTime: DHCP: Lease Seconds: 1200

*Aug 27 14:56:15.751 PCTime: DHCP: Server ID Option: 213.66.241.86

*Aug 27 14:56:18.751 PCTime: DHCPD: IP address change on interface ATM0.1

*Aug 27 14:56:18.751 PCTime: DHCPD: IP address change on interface ATM0.1

*Aug 27 14:56:18.751 PCTime: DHCP: Releasing ipl options:

*Aug 27 14:56:18.751 PCTime: DHCP: Applying DHCP options:

*Aug 27 14:56:18.751 PCTime:   Setting default_gateway to 81.230.121.65

*Aug 27 14:56:18.751 PCTime:   Adding default route 81.230.121.65

*Aug 27 14:56:19.751 PCTime:   Adding route to DHCP server 213.66.241.86 via ATM0.1 81.230.121.65

*Aug 27 14:56:19.751 PCTime:   Adding DNS server address 195.67.199.39

*Aug 27 14:56:19.751 PCTime:   Adding DNS server address 195.67.199.40

*Aug 27 14:56:19.751 PCTime: DHCP: Sending notification of ASSIGNMENT:

*Aug 27 14:56:19.751 PCTime:   Address 81.230.121.83 mask 255.255.255.192

*Aug 27 14:56:19.751 PCTime: DHCP Client Pooling: ***Allocated IP address: 81.230.121.83

*Aug 27 14:56:19.803 PCTime: Allocated IP address = 81.230.121.83  255.255.255.192

*Aug 27 14:56:19.803 PCTime: %DHCP-6-ADDRESS_ASSIGN: Interface ATM0.1 assigned DHCP address 81.230.121.83, mask 255.255.255.192, hostname elsa

*Aug 27 14:56:25.751 PCTime: DHCP: Client socket is closed

*Aug 27 15:06:18.759 PCTime: DHCP: Client socket is opened

*Aug 27 15:06:19.759 PCTime: DHCP: QScan: Bound..T1 fired..Renewing

*Aug 27 15:06:19.759 PCTime: DHCP: SRequest attempt # 1 for entry:

*Aug 27 15:06:19.759 PCTime: Temp IP addr: 81.230.121.83  for peer on Interface: ATM0.1

*Aug 27 15:06:19.759 PCTime: Temp  sub net mask: 255.255.255.192

*Aug 27 15:06:19.759 PCTime:    DHCP Lease server: 213.66.241.86, state: 7 Renewing

*Aug 27 15:06:19.759 PCTime:    DHCP transaction id: 914

*Aug 27 15:06:19.759 PCTime:    Lease: 1200 secs,  Renewal: 600 secs,  Rebind: 1050 secs

*Aug 27 15:06:19.759 PCTime: Temp default-gateway addr: 81.230.121.65

*Aug 27 15:06:19.759 PCTime:    Next timer fires after: 00:03:46

*Aug 27 15:06:19.759 PCTime:    Retry count: 1   Client-ID: cisco-d48c.b524.7b17-AT0.1

*Aug 27 15:06:19.759 PCTime:    Client-ID hex dump: 636973636F2D643438632E623532342E

*Aug 27 15:06:19.759 PCTime:                        376231372D4154302E31

*Aug 27 15:06:19.759 PCTime:    Hostname: elsa

*Aug 27 15:06:19.759 PCTime: DHCP: SRequest - ciaddr: 81.230.121.83

*Aug 27 15:06:19.759 PCTime: DHCP: SRequest: 293 bytes

*Aug 27 15:06:19.759 PCTime: DHCP: SRequest: 293 bytes

*Aug 27 15:06:30.759 PCTime: DHCP: Client socket is closed

*Aug 27 15:10:04.759 PCTime: DHCP: Client socket is opened

*Aug 27 15:10:05.759 PCTime: DHCP: QScan: Renewal..Retrying

*Aug 27 15:10:05.759 PCTime: DHCP: SRequest attempt # 2 for entry:

*Aug 27 15:10:05.759 PCTime: Temp IP addr: 81.230.121.83  for peer on Interface: ATM0.1

*Aug 27 15:10:05.759 PCTime: Temp  sub net mask: 255.255.255.192

*Aug 27 15:10:05.759 PCTime:    DHCP Lease server: 213.66.241.86, state: 7 Renewing

*Aug 27 15:10:05.759 PCTime:    DHCP transaction id: 914

*Aug 27 15:10:05.759 PCTime:    Lease: 1200 secs,  Renewal: 600 secs,  Rebind: 1050 secs

*Aug 27 15:10:05.759 PCTime: Temp default-gateway addr: 81.230.121.65

*Aug 27 15:10:05.759 PCTime:    Next timer fires after: 00:01:53

*Aug 27 15:10:05.759 PCTime:    Retry count: 2   Client-ID: cisco-d48c.b524.7b17-AT0.1

*Aug 27 15:10:05.759 PCTime:    Client-ID hex dump: 636973636F2D643438632E623532342E

*Aug 27 15:10:05.759 PCTime:                        376231372D4154302E31

*Aug 27 15:10:05.759 PCTime:    Hostname: elsa

*Aug 27 15:10:05.759 PCTime: DHCP: SRequest - ciaddr: 81.230.121.83

*Aug 27 15:10:05.759 PCTime: DHCP: SRequest: 293 bytes

*Aug 27 15:10:05.759 PCTime: DHCP: SRequest: 293 bytes

*Aug 27 15:10:16.759 PCTime: DHCP: Client socket is closed

*Aug 27 15:11:57.759 PCTime: DHCP: Client socket is opened

*Aug 27 15:11:58.759 PCTime: DHCP: QScan: Renewal..Retrying

*Aug 27 15:11:58.759 PCTime: DHCP: SRequest attempt # 3 for entry:

As pointed to you in my previous mails  renews/packets are being sent and as router is not getting back any reply, lease is timing out and that’s  the reason why the interface is getting flapped. You need to find with ISP  why the renews and rebind packets are not responded to by Providers DHCP server.

Hope this clarifies your query.

Thanks and regards,

Lijesh

-------------------

New Member

Re: Cisco 867VAE drops connection on DHCP lease timeout

Thanks Daniel.

You don't happen to remember the debug commands to get that output do you?

Thanks
Mario

Sent from Cisco Technical Support iPhone App

New Member

Debug output could be

Debug output could be redirected to syslog server
logging trap debugging
logging my.syslog.server

 

New Member

About problem of dropping

About problem of dropping connections with DHCP – its our (users) bug not IOS
I found in your config line:
ip nat inside source static 192.168.200.100 interface ATM0.1
All traffic is forwarded to your local server 192.168.200.100 including answers from DHCP server of your internet provider.
DHCP server accept queries on udp port 67 and send answers to client on udp port 68.
You could insert one line:
ip nat inside source static udp 192.168.200.1 68 interface ATM0.1 68
and dhcp answers will go to your router.
Best regards.

 

New Member

Oh wow, thank you. I've never

Oh wow, thank you. I've never given that a though, and nor did the Cisco support who took my case.

I'll try this out!

New Member

Hi there, yes i forgot to

Hi there, yes i forgot to update that I had the same issue. i had a static NAT port forwarding everything, including the DHCP responses from the ISP.

However, what I could not get to work was to have a static NAT portforwarding everything, together with a static NAT only portforwarding the DHCP responses... The NAT forwarding everything always took precidence.

If you manage to get this working, please let me know.

thanks

Mario

New Member

Could you post your config

Could you post your config

New Member

Could I quickly hijack my own

Could I quickly hijack my own thread to ask how to properly port forward a range of ports? We need loads of SIP ports (both TCP and UDP, like 9000-9999 to IP 192.168.200.100 for example) forwarded to the server, and my knowledge of IOS is still limited. That's why I made static NAT to begin with...

Only if you have time on the fly as this should really be a separate thread if anything :) Cheers

PS. I've searched for it, but there are so many different answers I get confused.

New Member

I never tried it:https:/

I never tried it:
https://supportforums.cisco.com/discussion/11593786/nat-udp-port-range-forwarding-howto
but as you could see may be some problems with udp.
Easiest way insert only 2 lines in config:
ip nat inside source static 192.168.200.100 interface ATM0.1
ip nat inside source static udp 192.168.200.1 68 interface ATM0.1 68
In case of Asterisk PBX better to choose IAX protocol it use only one port also it has better performance.

HelloYou have active DHCP

Have you got this working?

Please don't forget to rate any posts that have been helpful. Thanks.

HelloSo you are still having

Hello

So you are still having problems with Dropping connection?

 

res

Paul

Please don't forget to rate any posts that have been helpful. Thanks.
New Member

Hello Paul,I don't know yet.

Hello Paul,

I don't know yet. I haven't had the chance to try it out yet, sadly. It's been hectic lately and internal problems like these have to fall behind.
I will for sure try this out next week however, and I'll update with correct answer etc accordingly.

Regards
Daniel

New Member

Hello everyone!I'll just take

Hello everyone!

I'll just take this moment to thank slavochka (and the rest of you for helping) for the solution. We're running without any hickups now, as soon as I entered:

ip nat inside source static udp 192.168.200.1 68 interface ATM0.1 68

I noticed that the correct answer is already marked, but consider this thread fully closed now :)
Still funny that the Cisco support didn't manage to find this, but I know they're humans too.

Cheers!
 

Regards
Daniel 

 

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