My router keeps losing internet connection

[emp41112]

To fix it I went to the status page of DD-WRT and did a DHCP renew/release. By the way there is this there: Remaining Lease Time0 days 21:44:34 This is just after I did the renew/release.

p2p Peer to peer? No I am not doing that. Just surfing, Netflix streaming and gaming.

DNS is coming from ISP (roadrunner)

It happened here again about 20 minutes ago. (10:15pm Wed nite)

thanks

[+BudMan MVC]

Did correspond with the lease time?

[emp41112]

Not sure since I did not pay attention to what it was before. Now that I know I am keeping an eye on it.

[emp41112]

It is going along with the lease time. It went out last night, did the release/renew and new lease time was 12hr:59min:58sec. Just now 13 hours later, it died. Did the release/renew again and now lease time is just under a hour.

[+BudMan MVC]

Strange that your getting different lease times?? and 13 hours is a weird setting??

Your isp seems to be in the middle of changing ip ranges? Or maybe they change lease periods based on load??

Heres the thing.. Normally your box should always get the same address, even if the renew fails -- when it actually expires, the dhcp server should still give it the same IP you had before -- unless someone took it before you could get it back?

Normally the dhcp client will ask to renew around the 50% mark of the lease, so in your case on that 13 hour one, at 6.5 hours it would of asked for renew of the lease. If does not let it renew, depending on the client it will continue to ask and more frequent times until it actually expires.. Then it will go through the whole discovery process again looking for a dhcp server.

Does it tell you who your dhcp server is on the router? Is that changing as well? Maybe they have dhcp servers going on and offline.. So for example if you get lease from server A, then server A goes offline you will not be able to renew -- then when finally expires you would get a IP from a different dhcp server, etc.

If you router status will not show you this -- you might want to directly connect your PC, which will show you the IP of the dhcp server it got the lease from using ipconfig /all

[emp41112]

Just looked to write down my IP and server info that the router is getting. Lease time went from a hour to 23:52:10

Information I wrote down was the IP, Subnet, Gateway, and DNS info that the router has from my ISP. I will check and see if this changes next time it happens.

[+BudMan MVC]

Depending on the features of your router, or what os your running and what dhcp client, etc.. you can get lots of good troubleshooting info from the logs or lease info that is stored.

So for example I run a linux distro as my router (pfsense) so have full access to lots and lots of info. Here is my lease info for my wan interface.

As you can see tells me when it will attempt rebind, renew, etc. And when it actually expires, the dhcp server - the lease time -- all the info given in the lease, etc.

It sure looks like to me your having a problem with maintaining a lease - be it your ISP doing stuff with their servers, the lease times, etc.. or a problem with your router and their servers talking to each other correctly.. Could be a combo of of things cause you grief.

Only thing I can suggest if you don't have full access to your client so you could run scripts to renew on its own out of schedule, etc. is to just keep an eye on the lease time -- and try and renew new it on your own to get a longer lease, so it should not disconnect when your not wanting it too. But if you say you got 1 hour, and then a bit later it changed to 12 hours -- when your client renewed at the 30 minute mark of the 1 hour lease I would guess.. Then sure seems like they are doing something weird with their servers..

[emp41112]

Ok man, thanks for all the help you gave me. I will just keep an eye on it and see what happens.

Thanks!

[emp41112]

Ok so it is still happening, but not as often. I noticed too now that when I lose internet, if I try to ping the modem thru the router I get no response until I do the DHCP renew/release. After A few times of doing that I get my ineternet connection back and can then ping the modem.

Is my router somehow blocking my modem?

[+BudMan MVC]

And so clearly sounds like dhcp issue like I stated.

When you say

"if I try to ping the modem thru the router"

Sure sounds like your behind a double NAT. But your connected to just a cable modem 2100, what IP are you pinging?? 192.168.100.1 ?? Kind of hard to ping anything if your router does not have a IP address ;)

If it works after renew/release a few times on your router - then it sure sounds like a dhcp issue.. Are you keeping track of when it goes out an what lease you have, or what dhcp server you got the info from -- did it change? etc..

[emp41112]

Yeah I need to start tracking that information again. Nothing changed, still on the Linksys modded with DD-WRT that you linked earlier and the same cable modem.

Do you think the DHCP issue is with my ISP or the router? I do know that when I do the release and renew, the IP has been the same.

Thanks

[emp41112]

Ok, so it seems about every 12 to 14 hours it dies. This is the half way point of the stated lease time. Does this mean it is having trouble getting a new lease at the half way point?

What could be some steps I take to remedy this?

[+BudMan MVC]

yes normal/common behavior with dhcp is at the 50% mark in the lease it will try and renew, this could be different for different dhcp clients - but in general yes at the 50% the client will attempt a renew of the lease.

Here is a pretty good walk through for dhcp in general

http://www.tcpipguide.com/free/t_DHCPConfigurationandOperation.htm

Your running dd-wrt on the router right? You should have access to the details of the lease, etc. And should be able to just run from shell access to the router dhcpclient interface to renew, and watch what happens, does it renew?? If so you could script that to run like every hour. There should be detailed information in the dhclient.leases file.

I currently do not use my wireless router as gateway, so its wan interface is disabled and does not grab dhcp IP.. But I could connect it and do some playing with the dhcpclient on it, etc.

Some clients just have issues with renewal from specific servers, sometimes you can pad the request (some don't like the small packets) etc.

Your going to have to get some details before you could figure out what is going wrong.. you should be able to view some logs on your router, or run the client directly to see what is happening, etc.

Other option is to just change the router or firmware on the router to see if that fixes the problem? What version of the dd-wrt are you running? is it the latest, beta? what?

[emp41112]

Ok, I will look into the details of the lease. Thanks for that link, Hopefully I learn something from it. Going to do some more rooting around and check out more of the settings.

Thanks for all the help.

If all else fails I will ask Santa for a new router

Thanks

[emp41112]

Did a little searching about telnet and commands for DD-WRT. I cannot find the logs for the DHCP to observe what is going on there. Have any suggestions, or can you point me in the right direction...

However while searching on telnet commands and scripts I found this

killall -SIGUSR2 udhcpc

killall -sigusr1 udhcpc

So to test it out I logged onto my router using telnet. I ran "killall -SIGUSR2" udhcpc and immediatly lost my IP from the modem. I then ran "killall -sigusr1 udhcpc" and immediatly got my IP again. (no quotes)

When I enter these commands into the command window under the Administration page Command tab, it will renew my ip much faster then if I do the renew/release button under the status page.

Is there a way I can automate these commands to renew/release my IP at a certain time?

At least I am learning something here with the telnet stuff