[ale] Comcast Business service

Michael Trausch mike at trausch.us
Mon Jun 15 00:07:51 EDT 2015


You'll want to read up on the DHCP spec for more information, but basically:

- modem asks for lease. If it has never had one, the address it gets is random, otherwise it will ask for the address it had previously. DHCP server need not honor the request but it will typically do so if it can.

- client can timeout, renew lease at between 50-100% of lease lifetime, or release the lease. In the last scenario it is typical for the device to forget it's old IP address, but by no means required.

Most of the time, systems will retain their IP on a dhcp network unless the network is very near, at, or over capacity (more hosts demanding IPs than available IPs) or the lease lifetime is so low that hosts (mostly older ones) ignore it. This is why both dhcp server and client are required to ping/arp to find out if the address is already in use. 

Sent from my iPhone

> On Jun 13, 2015, at 3:45 PM, Boris Borisov <bugyatl at gmail.com> wrote:
> 
> I have residential and my ip stays the same for past two months even I've had modem power rebooted few times. How often is supposed to change?



More information about the Ale mailing list