Wierd DHCP lease issue

Junglist2k5 · 31-08-2006, 10:58

hi, quick question, do any of you guys know why my cable modem might change ip adresses from 86.2.161.* to 86.0.222.* every 2 days, even though i dont restart it at all? It seems rather odd and buggers up my wireless router.

It used to have a contstant address until left off for a long time, as one would expect with a DHCP lease.

31-08-2006, 11:04

Why does it bugger up your router? It is the router which gets the DHCP lease, and should renew this after half the lease period (i.e. after 24 hours). The only problems I can see is a) if you power the router off or b) if you've given the router a fixed IP.

**Kevin T** · 31-08-2006, 11:07

See this thread. His router doesn't seem to renew its lease...

Junglist2k5 · 31-08-2006, 11:14

Quote:

Originally Posted by Cobbydaler

See this thread. His router doesn't seem to renew its lease...

this is my thread, sorry about the sort of double post, as that thread was moved

---------- Post added at 11:14 ---------- Previous post was at 11:12 ----------

Quote:

Originally Posted by JohnHorb

Why does it bugger up your router? It is the router which gets the DHCP lease, and should renew this after half the lease period (i.e. after 24 hours). The only problems I can see is a) if you power the router off or b) if you've given the router a fixed IP.

it doesnt renew leases at all!!!

but the question remains about dhcp changing on my modem,

is it not odd?

31-08-2006, 11:18

AFAIK it is the router which gets the IP address, NOT the modem. If the router does not renew DHCP leases, that would explain the problem, but I'm a bit confused. I would have thought that if the router does not RENEW leases, it wouldn't request new ones either

Junglist2k5 · 31-08-2006, 11:31

Quote:

Originally Posted by JohnHorb

AFAIK it is the router which gets the IP address, NOT the modem. If the router does not renew DHCP leases, that would explain the problem, but I'm a bit confused. I would have thought that if the router does not RENEW leases, it wouldn't request new ones either

Its an odd problem, the router doesnt request a new address AFAIK, but I lose WAN connectivity after 2 days, the only way to reconnect is to reboot, therfore asking for a new address, which i would expect to be the same, but its not! its a totally different network!

---------- Post added at 11:31 ---------- Previous post was at 11:21 ----------

i wonder if there is a ntl router problem down the line from me causing this weirdness, I would ring them but they seem to have 100s of people calling at th e mo.

31-08-2006, 11:33

NTL won't want to know, unless you get the same issue with a PC directly connected to the modem.

Junglist2k5 · 31-08-2006, 11:43

Quote:

Originally Posted by JohnHorb

NTL won't want to know, unless you get the same issue with a PC directly connected to the modem.

that doesnt happen because the pc does renew the address, it just seems so odd that one day ive got ip 86.2.161.* the next ive got 86.0.222.*, I used to have a pool of 254 addresses and it never changed while the modem remained on.

looks like ive hit a brick wall then

---------- Post added at 11:43 ---------- Previous post was at 11:39 ----------

seems strange no one else seems to have this issue either?

maverick · 31-08-2006, 13:05

Check the router firewall is not denying DHCP requests,if it does then what your getting will happen.

Junglist2k5 · 31-08-2006, 13:35

Quote:

Originally Posted by maverick

Check the router firewall is not denying DHCP requests,if it does then what your getting will happen.

no, the firewalling is disabled