07-07-2015 10:08 AM
Apple devices ignoring DHCP rules - using up all my IP addresses on the FiOS-G1100
I have now gone through two of the new quantum gateways and both allow Apple devices of all kinds to bypass the lease time that I set to something like 129600 Minutes for that specific IP Address (which is 90 days, or three months). People using our guest network end up taking all our non-static addresses and then we have none left to issue out to other users or staff. I'm about to receive my third g1100 from Verizon and I'm pretty sure it's not the box but the firmware. I've had to do 2-3 hard resets on both boxes since Jan '15 to erase everything and start over with loading custom settings back in. A Huge pain.
Once all addresses are taken up and you login as Admin on the router, half of the UI options have now disappeared. Also in general there is no way to manually force the router to expire LAN IP addresses even after a hard reset. Or is there and I just have never seen this option?
Anyone else experience this? I've spent about 3 hours with multiple reps who either don't believe me or have no idea how their product works. I'm beginning to either think I'm crazy or there's a bug and no one has reported it yet.
07-07-2015 05:17 PM - edited 07-07-2015 05:19 PM
Your lease time may be causing a bug in the DHCP client on Apple devices. That is an unusually long lease time so I wouldn't be surprised if it was something like an integer vs float vs signed integer problem in the code. Please consider cutting the leases down to 3600 minutes, and then use DHCP Reservation for any devices that you own which you would like to keep on a fixed IP.
Now if this is for guest devices, consider limiting your least time to 30 to 60 minutes. Many devices are mobile and do not need 90 day long leases. That's wasteful of an otherwise limited IP subnet.
07-08-2015 12:28 PM
i just spent the last 2 weeks dealing with this.
This is a bug in the G1100 routers DCHP server. Apple mobile devices may request lease times of 90 days. The G1100 router will grant this ignoring the configured limit. I manage a network that sees enough apple devices to run out of addresses in about 5 days. Until I can find an alternate solution, I have found a better method to flush the DHCP table. Setting the Ip address distubution to start:192.168.1.254, end: 192.168.1.254 will remove all but the 254 address from the database. It does not remove any address that is marked as static. Then reconfigure the start address back to the original setting. I had to enable remote web management so I can do this when nobody is on the network. Still a huge pain.
i have found that when the granted client list gets too long, the Ui behaves badly making debugging this problem much more difficult. The "My Network" option will show zero attached devices and the DHCP connections list shows nothing.
07-08-2015 01:27 PM
YES! THIS is what I'm talking about. I limit the lease times to 20 minutes, and have done that for awhile now but the Apple devices request and GET their 90-day lease time. I, too, also see enough Apple devices to fill up my subnet in about a week or two.
I haven't tried the trick with starting the IP Distro with .254 and ending in 254. That's a neat trick. I will try that the next time. I won't worry about the remote management only because I have remote access to everything on the network and live down the street from our offices - Still a huge pain indeed. And no Verizon tech support could help or even look into the situation. I hope this raises awareness a little further. Otherwise, I'll have to build a DHCP server off one of our other boxes.