DHCP Lease time adjustment

[Gringo_the_Kid]

Anyone know why Xfinity sets their WAN DHCP lease expiration times to less than two hours?

it's dumb because my internet keeps dropping and their chatbot won't let me talk to anyone

that can help and they muted my post on their forum about it so no one can see it.

You'll see the post in the picture is private but I didn't mark it that way and I can't change it.

 

[Skiiwee29]

Usually this is due to not having enough IP space left to leave it at the normal 24hrs so they can quickly reclaim any unused IPs back before they run into having zero IP space left. This is something controlled on the Xfinity DHCP server and not on your modem. These settings affect all subscribers, not just you. In my experience though, the DHCP lease process isn't customer impacting as it should happen without any noticeable impact. I've had them set as low as 5 minutes due to IP space issues and never heard of any subscriber impact.

 

Take this with a grain of salt as this is just pure speculation on my part and based on my personal experience with hosting/running/managing DHCP servers for ISPs.

[Donut417]

24 minutes ago, Gringo_the_Kid said:

Anyone know why Xfinity sets their WAN DHCP lease expiration times to less than two hours?

Im pretty sure I have heard of this before. Maybe they are doing some kind of maintenance or upgrades in the area. They operate a direct forum at DSLreports.com, maybe post there, as the post is only seen by Comcast employees and they might be able to give you better answers. But as stated above, the WAN IP is controlled by their DHCP server not the modem, so there is nothing you can physically do. 

[Gringo_the_Kid]

Thanks but it would suck if they've just been doing maintenance for almost two years 

[BiotechBen]

1 hour ago, Gringo_the_Kid said:

Anyone know why Xfinity sets their WAN DHCP lease expiration times to less than two hours?

it's dumb because my internet keeps dropping and their chatbot won't let me talk to anyone

that can help and they muted my post on their forum about it so no one can see it.

You'll see the post in the picture is private but I didn't mark it that way and I can't change it.

 

 

51 minutes ago, Skiiwee29 said:

This is something controlled on the Xfinity DHCP server and not on your modem. These settings affect all subscribers, not just you.

This is what I see on my end with my Xfinity service when logged into the interface.

[Skiiwee29]

Just now, BiotechBen said:

 

This is what I see on my end with my Xfinity service when logged into the interface.

Every IP scope deployed has its own lease timers, so yours might be set to default. Usually IP Scopes are deployed on a cable bundle on a CMTS for specific regions so some may have more IP space available to them than others. A lot of factors play into how they deploy the IP space and what size CIDR to assign.

[Falcon1986]

27 minutes ago, BiotechBen said:

This is what I see on my end with my Xfinity service when logged into the interface.

The OP is referring to the WAN side, not the local/LAN side.

[manikyath]

a short lease time shouldnt cause drops, unless they forcefully recycle and reallocate every two hours, which sounds like an absolutely ridicuous process.

[Donut417]

6 hours ago, Gringo_the_Kid said:

Thanks but it would suck if they've just been doing maintenance for almost two years 

They do maintenance all the time, it's kinda the job of the ISP. Also they are in the middle of Midsplit and Docsis 4.0 upgrades. 

 

Are you sure it's the lease time thats the issue and that you dont have an underlying signal issue?