Computer Hope

Internet & Networking => Networking => Topic started by: mikeydat5111 on April 07, 2009, 11:44:02 AM

Title: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: mikeydat5111 on April 07, 2009, 11:44:02 AM
Hi,

We've been having this problem for awhile. 
I setup all of our PC's (xp pro os) to access our linksys router WRT54gs to get an IP address automatically through the DHCP server and have set the range on the dhcp server  to fall between 192.168.1.101 through 150.  This will work fine for awhile then like last night all of the ip address issued were out of range such as 169.254.27.3.  Then the only way I can get the pc's to get a proper address is to hard code the address into the properties of the TCP/IP setting in the network connections properties dialog box.  So any ideas as to what is up?
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: brundle on April 08, 2009, 12:14:33 PM
Wired or wireless connections?

A 169.x.x.x address means the machines can't find, or are not responding to the DHCP server, as you must have surmised.  Windows assigns one of its own (APIPA).

What happens if you use the

ipconfig /release
ipconfig /renew

command(s) at the prompt on one of the machines?

Have you checked the DHCP lease period and idle timer on the router (the latter is only relevant for wireless connections)?

Have you gone into the device properties for each NIC and made sure that Power settings are configured so that the NICs aren't allowed to switch off to save power?
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: mikeydat5111 on April 08, 2009, 01:04:38 PM
Brundle Thanks for replying.

All of the offending pc's are wired.

When using ipconfig /release it will release the ip and then if you try to ipconfig /renew it goes back to a 169.x.x.x configuration. 
It  seems that the DHCP server works for awhile and then quits.

lease period is 1440 min or 24 hr

The nic power properties are not set to switch off.

These are all great ideas unfortunately none seem to be the problem, maybe we have an intermittent problem DHCP server. 

Is there any way to check the DHCP server, to see if it responds consistently.
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: brundle on April 08, 2009, 01:54:56 PM
Given that all machines lose their IP address at the same time, the router appears to be the problem but it's worth disconnecting all but one machine and seeing if the same problems occur.

Monitor the remaining NIC with Wireshark - if you issue an ipconfig /renew command you should see 255.255.255.255 Discovery broadcasts from the client looking for a DHCP server, then a unicast back from the server with a DHCP Offer (the first two of the 5 message types used in DHCP). That would be a starting point. If things seem to improve, add another machine and keep monitoring the DHCP messages. Ideally you want it to break while you're monitoring to see what's actually happening - if things improve with only one machine connected, start adding more.

Worth checking the DHCP Client service is running on all machines too.
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: fgdn17 on April 09, 2009, 09:49:48 AM
Hi,

We've been having this problem for awhile. 
I setup all of our PC's (xp pro os) to access our linksys router WRT54gs to get an IP address automatically through the DHCP server and have set the range on the dhcp server  to fall between 192.168.1.101 through 150.  This will work fine for awhile then like last night all of the ip address issued were out of range such as 169.254.27.3.  Then the only way I can get the pc's to get a proper address is to hard code the address into the properties of the TCP/IP setting in the network connections properties dialog box.  So any ideas as to what is up?



routers seem to do that...unplug the router, count to 10 then plug it back in...should solve it...good Luck
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: mikeydat5111 on April 13, 2009, 10:07:10 AM
Thank you fgdn17 for your input, it turned out to be the simple solution, to my IP  problem.

In the future I will move re-booting the router, to the beginning of the to do list when trying to solve out of range ip's problems with the router.

Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: brundle on April 14, 2009, 02:15:39 PM
Thanks for coming back with answer...why didn't I think of that.... ;D
Title: Re: Linksys router wrt54gs, dhcp server issues out of range IP address
Post by: mikeydat5111 on April 15, 2009, 09:21:25 AM
Thanks Brundle for your interest and input, I guess we all get to learn from keeping it simple.

If routers periodically lose their way in the DHCP server world does anyone have an idea as to why this is happening.  The router and the switches are all protected with a fairly robust UPS.  Other than starting the day with  a visit to the router and turning it off and then on is there any thing one could do to keep this from happening?