DHCP server is not releasing expired lease
-
@SteveITS said in DHCP server is not releasing expired lease:
Some sort of odd file corruption?
Maybe because I can not duplicate the problem - as you saw before my dhcp scope is used.. All the IP in the scope have been handed out.. So I know just phone to that vlan, letting it use a different mac (private stuff)..
And you can see it grabbed an old expired lease .104, and assigned it to my phone connection..
What specific version of pfsense are you on? I am on 23.05.1 - I could try and duplicate the problem on my old 2.6 vm, or 2.7 vm - but take me a bet to test it out..
-
@SteveITS it persist across version upgrade and reboots
-
@johnpoz said in DHCP server is not releasing expired lease:
@SteveITS said in DHCP server is not releasing expired lease:
Some sort of odd file corruption?
Maybe because I can not duplicate the problem - as you saw before my dhcp scope is used.. All the IP in the scope have been handed out.. So I know just phone to that vlan, letting it use a different mac (private stuff)..
And you can see it grabbed an old expired lease .104, and assigned it to my phone connection..
What specific version of pfsense are you on? I am on 23.05.1 - I could try and duplicate the problem on my old 2.6 vm, or 2.7 vm - but take me a bet to test it out..
I am on 23.05.01
Actually, I have already removed all expired lease so I can't reproduce it right now until I have more expired lease. However, I did find a lot of similar case that wasn't resolved
https://forum.netgate.com/topic/143143/dhcp-leases-are-not-automatically-released/16
https://forum.netgate.com/topic/137042/dhcp-service-not-renewing-ip-lease
https://forum.netgate.com/topic/166995/remove-dhcp-leases-automatically/15
https://forum.netgate.com/topic/46897/dhcp-addresses-not-releasing
I am not sure if some particular condition would make the dhcp server not reusing expired ip address.. However, I am 100% sure the DHCP server wasn't releasing IP address when I first wrote this post. I got a new phone and try to connect to the LAN, the phone wouldn't connect to the LAN via wifi. No IP is assigned. Then I started looking into the log and see what happened, and I found that DHCP server is complaining no free lease. So, I looked at the dhcp lease page (the first screenshot on first post) and found that many expired lease stuck in that page and none of those IP address were re-used. This was how I found out the problem.
i end up removing all the expired leases , make the pool a bit bigger and voila the new phone connect to the LAN via wifi. So...it's something fishy on the dhcp server...
-
@sdugoten while I do recall past posts with sim issue, I don't recall ever being able to duplicate the problem..
I would attempt to duplicate it quickly, create a small scope, just a few addresses with really short lease time, and then run through seeing if it will issue an expired lease.
You might want to do just a clean flush of the whole leases file, and let it create new file.
The leases file is stored here
/var/dhcpd/var/db
I would shut down dhcp services on all interfaces, then delete the files there will also be a leases~ file and then restart your dhcp services..
-
@johnpoz said in DHCP server is not releasing expired lease:
@sdugoten while I do recall past posts with sim issue, I don't recall ever being able to duplicate the problem..
I would attempt to duplicate it quickly, create a small scope, just a few addresses with really short lease time, and then run through seeing if it will issue an expired lease.
You might want to do just a clean flush of the whole leases file, and let it create new file.
The leases file is stored here
/var/dhcpd/var/db
I would shut down dhcp services on all interfaces, then delete the files there will also be a leases~ file and then restart your dhcp services..
I just stopped the dhcp server service, rename the existing lease file to mydhcpd.leases and then delete all other files. When I restarted the dhcpd service, i saw there is one file owned by root, but not dhcpd. Is that intentional?
Before image is like this
-
All my files owned by dhcp:
-rw-r--r-- 1 dhcpd _dhcp 45947 Jul 9 08:57 dhcpd.leases -rw-r--r-- 1 dhcpd _dhcp 50594 Jul 9 08:48 dhcpd.leases~ -rw-r--r-- 1 dhcpd _dhcp 0 May 16 16:28 dhcpd6.leases -
@sdugoten yeah I don't think it should be owned by root.
[23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db: ls -la total 35 drwxr-xr-x 2 dhcpd _dhcp 6 Jul 9 06:29 . drwxr-xr-x 4 dhcpd _dhcp 4 Feb 14 2022 .. -rw-r--r-- 1 dhcpd _dhcp 25151 Jul 9 06:29 dhcpd.leases -rw-r--r-- 1 dhcpd _dhcp 25841 Jul 9 06:29 dhcpd.leases~ -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases~ [23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db: -
@johnpoz said in DHCP server is not releasing expired lease:
@sdugoten yeah I don't think it should be owned by root.
[23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db: ls -la total 35 drwxr-xr-x 2 dhcpd _dhcp 6 Jul 9 06:29 . drwxr-xr-x 4 dhcpd _dhcp 4 Feb 14 2022 .. -rw-r--r-- 1 dhcpd _dhcp 25151 Jul 9 06:29 dhcpd.leases -rw-r--r-- 1 dhcpd _dhcp 25841 Jul 9 06:29 dhcpd.leases~ -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases~ [23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db:This was the steps I did
- Stop the dhcp service in LAN interface under service
- rename the original dhcpd.leases to mydhcpd.leases
- delete all other files
- check the checkbox in dhcpd lan interface to enable it again
Files generated as the screenshot above with root ownership.
-
https://redmine.pfsense.org/issues/4936
-
@sdugoten while yeah I see, that doesn't seem right to me..
I found this
https://redmine.pfsense.org/issues/4936
dhcpd sets wrong permissions on leases files
-
@guile haha - you beat me too it ;)
Had you looked at these files when you were having the issue - I wonder if was owned by root, and that is why were having no free leases. And then you clearly the old leases fixed the file to have dhcpd owner??
That redmine seems to indicate getting a no leases error when was owned by root..
-
@sdugoten said in DHCP server is not releasing expired lease:
@johnpoz said in DHCP server is not releasing expired lease:
@sdugoten yeah I don't think it should be owned by root.
[23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db: ls -la total 35 drwxr-xr-x 2 dhcpd _dhcp 6 Jul 9 06:29 . drwxr-xr-x 4 dhcpd _dhcp 4 Feb 14 2022 .. -rw-r--r-- 1 dhcpd _dhcp 25151 Jul 9 06:29 dhcpd.leases -rw-r--r-- 1 dhcpd _dhcp 25841 Jul 9 06:29 dhcpd.leases~ -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases -rw-r--r-- 1 dhcpd _dhcp 581 Dec 9 2022 dhcpd6.leases~ [23.05.1-RELEASE][admin@sg4860.local.lan]/var/dhcpd/var/db:This was the steps I did
- Stop the dhcp service in LAN interface under service
- rename the original dhcpd.leases to mydhcpd.leases
- delete all other files
- check the checkbox in dhcpd lan interface to enable it again
Files generated as the screenshot above with root ownership.
I think that might be the original problem that not re-using ip address, just a wild guess.
However, I can reproduce this problem on Netgate 6100 with firmware 23.05.1-RELEASE (amd64). Even if you try to press this button
to remove all leases, it will blank out the lease file, but the ownership of the file "dhcpd.leases~" will change to root. However, the file "dhcpd.leases" still owned by dhcpd though
