DHCP on RT31P2 doesn't work

Posts: 19 · Vonage Forum Associate Joined: Jan 21, 2005 Posts: 19

I just installed my RT21P2 and cannot get DHCP to work correctly. I do NOT want it to issue new IP's every day, so I set the client lease time to 65000 minutes (about 45 days), yet it still issues new IP's every day. I switched over the static IP's last night, but would prefer to use DHCP. Has anyone else had a similar problem?

Posts: 448 · Posted: Fri Jan 21, 2005 10:13 pm Post subject: Re: DHCP on RT31P2 doesn't work

lohroffc wrote:

I just installed my RT21P2 and cannot get DHCP to work correctly. I do NOT want it to issue new IP's every day, so I set the client lease time to 65000 minutes (about 45 days), yet it still issues new IP's every day.

New IPs? Or do you mean it shows those IPs as renewed each day? When a host receives a DHCP assignment, it will attempt to keep that IP indefinitely by requesting renewal of that same address. When you shut down a PC, it releases its IP, only to request it again when it boots. If you're seeing daily renewals, and you shut down your machines at night.... well, there's the explanation.

lohroffc wrote:

I switched over the static IP's last night, but would prefer to use DHCP.

Everyone is entitled to run their own network however they see fit so please don't misunderstand my inquisitive tone... but I must admit I'm curious why you seem so opposed to static addressing. (unless you change the hosts on your LAN frequently)

Posts: 19 · Vonage Forum Associate Joined: Jan 21, 2005 Posts: 19

I haven't been shutting down my machines. One of my machines is a replaytv and it never gets turned off, yet everyday it was getting a new IP address. This was causing problems because you can share files over the web with ReplayTV, and to accomplish this, I have to set up port forwarding. When my replay gets a new IP, my port forwarding breaks.

By the way, no offense taken at your response. I prefer DHCP for 2 reasons. First, I was having trouble getting static IP's to work the first time I tried to set them up (my own ineptitude). Secondly, when I bring my laptop home from work (where we use DHCP), I now have to go into the network connector and assign an IP. I also have friends that bring computers over, and when they plug in, we have to assign IP's instead of letting DHCP do the work.

It's not a huge deal, just wondered if the problem was unique to me. The really annoying thing is that I called tech support about the problem to report it, and they called me back at 1 AM. What is up with that?

Posts: 23 · Vonage Forum Associate Joined: Jan 12, 2005 Posts: 23

I had my wireless network set up, and it uses that DHCP thingy..I dunno what it is, but I know that's what it uses, cause my PS2 uses that as part of my network too. I've had no problems being online, playing PS2 online, and talking on my Vonage phone simultaneously..

Posts: 19 · Vonage Forum Associate Joined: Jan 21, 2005 Posts: 19

I don't expect that you would have problems. I can do all of that as well. The problem is that with DHCP, every machine gets a new IP every day, which isn't a problem until you need one of your machines to keep the same IP address, which I do.

I've worked around the problem by setting up static IP's. I'm just curious if others have had the same issue.

Posts: 3198 · Posted: Sat Jan 22, 2005 9:29 am Post subject:

is the RT31P2 your only router? also, did you ever leave it at the default 0 (one day)? something to try anyway.

Posts: 227 · Vonage Forum Master Joined: Dec 10, 2004 Posts: 227

I don't use Linksys routers so someone else will have to answer this, but, can you setup DHCP reservations (this still uses DHCP but assigns the same IP address everytime based on the MAC address you provide)?

Posts: 448 · Posted: Sat Jan 22, 2005 10:43 am Post subject:

You can select the range of IPs to allocate thru DHCP. So (for sake of example) allocate 192.168.1.200 thru .254 for DHCP, and statically address your other hosts in the rang of .2 thru .199. That way the hosts that need to be on the same address are locked to that address, yet you can still use DHCP for your laptop and other devices that come and go.

I don't have an explanation why the device(s) is/are getting new IP addresses every day. That goes contrary to the principle of DHCP which says each host will try to renew (if online) or request (if booting) the same IP address perpetually. To cite my own case, Road Runner assigns my IP dynamically (DHCP) but because I never turn off my machine, I've had the same IP for the entire 3 years I've been a RR customer.

Posts: 19 · Vonage Forum Associate Joined: Jan 21, 2005 Posts: 19

Good idea on assigning static IP's below the range. I might give that a try, although since all is currently working, I think I'll save that for another day...

Regarding reserving IP's by MAC address, this does not appear to be possible with this router. I used that method with my previous router (D-Link DI-624 I think) and it worked swimmingly. I reserved an IP for my replayTV and let the other machines use DHCP.

Posts: 492 · Posted: Mon Jan 24, 2005 7:21 pm Post subject: DHCP On RT31P2 Doesn't Work

Call me old fashioned, but I prefer to leave well enough alone. Just my opinion. I set my RT31P2 to the default. I shut my systems down at night. DHCP issues a new IP address every now and then. Everything works just fine with no complaints.