DHCP lease time

ladiesman217

should dhcp least time be set for 10 mins? i experienced this problem from our isp assigning least time of 10 mins. i called the isp and told them about it but they keep telling me that their service is up and functional. they just told me to check the connection time to time. i do what they said till i got a steady connection. i then checked the dhcp least time and now its ok (7 days). im not just sure if my theory about the 10 min least time is the real problem so i want to ask your opinion guys.

Netstudent

I have never heard of a leasetime that short. That has the potential for a lot of uneeded broadcast traffic. Your address wasn't an APIPA was it?

ladiesman217

no its not starting at 169 which for i know is the arp address. they assigned me something like 192.168..... and thats what they assigned me now. but when i go to whatismyip.com it says my ip is 202.84..... . i think their using NAT here. but for the least time i think they made a mistake.

Netstudent

ya you are probably right.

KGhaleon

So your getting the address from a router or modem?

dynamik

What kind of connection is it and how do you have it setup?

As mentioned earlier, a ten minute lease would just create a little extra traffic. Your computer/router will attempt to renew the lease when half of the time has elapsed, so it will just ask to be renewed every five minutes. That in itself wouldn't cripple your connection.

However, If they're DHCP server is unavailable for more than ten minutes, you would run into problems.

ladiesman217

Im actually getting the address from the ISP’s DHCP server. The connection is a wireless broadband.

I’m using a router to connect to the ISP. I tried some trouble shooting, I disconnected the router and plug the cable directly in a desktop pc, I made the connection at first attempt, and I get redirected to their secure site for authentication. But after a few minutes same thing happens, I can’t get a stable connection. I made a lot of trial and errors to solve this problem, I use the router but problem is still there and changing from direct connection from pc to router made no difference. Ipconfig revealed the problem about the lease time. I’m really suspecting they made a mistake. But im not 100% sure since I don’t have enough knowledge about dhcp servers and ISP jobs. But im very curious to know what might be the culprit.

Mishra

If the cable plant needs to make a change then they will switch their DHCP lease times real short that way any clients needed to renew their address will pick up the shorter lease time as the configuration that they received is not the updated version.

I believe they do this sometimes when changes need to be made on their UBRs and CMTSs.

Now would that cripple your connection? I doubt it but a misconfiguration might have.