Kea DHCP stops working

stephenw10 · Jan 31, 2025, 11:45 PM

@onnastick said in Kea DHCP stops working:

I switched over to KEA as well just because I thought that's what the advice was, since ISC is deprecated.

It was at release. And still is for any other hardware. However this upstream bug has since been discovered in armv7. I'm running it here and haven't yet found any full workaround.

Patch · Feb 1, 2025, 4:34 AM

@Gertjan said in Kea DHCP stops working:

2.8.0 is in the works ...

LOL
The pubic access to daily build has been blocked since late 2023
pfsense Community v2.8 is a vaporware product which currently contains the majority of the pfsense redmine changes for the over 16 months through to July 2025

Don't hold your breath waiting for it to materialise.

MacUsers · Feb 12, 2025, 6:15 PM

I just experienced the very same issue with Kea, running v24.11 on 8200. The newly added device was getting an IP from the dynamic pool but wasn't able to receive the IP from the static mapping. I restarted Kea service for few times, removed the lock file etc. but nothing worked, until I restartd the box. So, the issue seems to be well present in the latest version as well.

stephenw10 · Feb 12, 2025, 7:14 PM

So you set a static mapping for a device that had a current dynamic lease but it failed to pull that until pfSense was restarted?

MacUsers · Feb 12, 2025, 7:58 PM

@stephenw10,
yes, exactly. And the strange thing was, that auto-assigned address wasn't being displayed under Status > DHCP Leases. The only way I could see what IP has been assigned was on the device itself.

stephenw10 · Feb 12, 2025, 8:45 PM

Are you sure the client was requesting a new lease? Or actually pulling one?

MacUsers · Feb 18, 2025, 9:55 PM

@stephenw10 I can confirm that static mapping for any new device is not working at all, at least for me. in last couple of days, I tried with three difrent devices and once it gets an IP from the dynamic pool, the only way to get the correct IP from the statuc maping is to reboot pfSense.

MacUsers · Feb 18, 2025, 9:57 PM

slowly thinking again, it's actually happening for me from the day one. It was for a different reasone but I reported here too:

https://forum.netgate.com/topic/196090/pfsense-behind-pfsense-not-getting-wan-ip-from-pfs1/7?_=1739914407057

stephenw10 · Feb 18, 2025, 11:48 PM

What I expect to happen here is the device keeps the dynamic IP lease until it tries to renew it.

If you cleared the leases in pfSense such that Kea doesn't show it at all are you sure it is actually pulling a new lease at all?

MacUsers · Feb 19, 2025, 3:34 AM

@stephenw10 I forced Renew DHC Lease on my MacBook after giving it a static-dhcp IP in PFS but it was still getting the old dynamic IP. But the strange thing is, that wasn't showing up under the Status >> DHCP Leases at all.

I haven't seen this before and it is happening with even the old devices. I replaced by DIY box with 8200 and upgraded to v24.11 at the same time - all I can say, it started happening after one of the either.

Just to give it a benefit of doubt: how do I chk that device was actually pulling a new lease?

MacUsers · Feb 19, 2025, 6:37 AM

okay, basically nothing is changng/updating related to DHCP. In one of the static-mappings, I provided custom DNS Servers (under the Server Options) and it's still showing the old DNS server address, even after restarting the client device. I'm very sure that it won't change, regardlessly what I do from/on the client side, nothing will change until I reboot the PFS box.

I'll restart and report here back soon.

stephenw10 · Feb 19, 2025, 3:34 AM

@MacUsers said in Kea DHCP stops working:

Just to give it a benefit of doubt: how do I chk that device was actually pulling a new lease?

The logging in Kea is (currently) unhelpful for that.

The only way to really know for sure would be to run a packet capture when the client renews and see what's actually being sent.

Gertjan · Feb 19, 2025, 6:37 AM

@MacUsers

The packet capture setup for DHCPv4 :

Select the interface you want to capture, typically LAN
The details : you want them all
It's UDP
and ports involved are 67 and 68.
Hit start.
Go to a device, and execute the DHCP Release and then DHCP renew command.

Get back to pfSense, and you should see a (1) packets coming in (the DHCP request) and the one packet getting send to the device with the DHCP lease info.

MacUsers · Feb 20, 2025, 7:18 PM

Okay, I do see the request hitting PFS when I release and renew the lease:

But no change in IP at all, as it should be 10.1.20.12 now as that's what the static mapping is now set:

This is happening for every single devices I have tested so far. Do you need the full capture?

stephenw10 · Feb 20, 2025, 8:55 PM

Hmm, note that it's requesting the old IP. If you clear the client side lease cache does it get the new static IP?

Might need to force that in Kea.

MacUsers · Feb 20, 2025, 9:00 PM

@stephenw10 I did everything: restarted Kea, cleared client side lease, even tried with a brand new device, predefined static mapping even before pluging in - not getting the actual IP if PFS not rebooted. Trying out all the usual stuff for almost a week now.
In case of the brand new device, it's getting an IP from the dynamic pool but that lease is not showing up in Status > DHCP lease at all.

MacUsers · Feb 20, 2025, 9:08 PM

@stephenw10 said in Kea DHCP stops working:

note that it's requesting the old IP

Question though - how it's gonna know what IP to ask for, in the first place?
AFAIK, device broadcasts a DHCP Discover message to find a DHCP server and the DHCP server responds with a DHCP Offer giving it an IP. Kea should offer the IP from static-mapping and after accepting that offer (followed by a DHCP Request), it should be Acknowledged by the server - is not what happens?

stephenw10 · Feb 20, 2025, 9:26 PM

Yes, but when it's renewing it will just request the old IP. And in some cases will just request an old cached lease address anyway. The server can refuse and issue a new lease.

However it sounds like it's just not seeing the new static lease entry.
Do you see the reservation listed in /usr/local/etc/kea/kea-dhcp4.conf?

MacUsers · Feb 20, 2025, 10:05 PM

@stephenw10 said in Kea DHCP stops working:

Do you see the reservation listed in /usr/local/etc/kea/kea-dhcp4.conf?

Yes, the IP is in the file against the correct MAC

but looks like not being offered?

MacUsers · Feb 20, 2025, 10:20 PM

@RobbieTT said in KEA DHCP - lacking features:

@maverickws

Before it went live it was suggested that encouraging users to leave ISC for Kea was rather over done, considering its immaturity.

I did switch to Kea during the beta period and it was seamless with no apparent drawbacks but once I released some basics were missing and that it was relying on previous ISC managed data to function, had me switching back.

As I understand it, simple static mappings / reservations from Kea are not actually supported. However, it may give an illusion of functionality if you have run ISC previously. Existing mappings / reservations will still be resolvable as the hosts file still contains them as a hang-over from running ISC. Any new mappings added or modified will not be resolvable.

To me, the ability to set a static mapping / reservation is a basic cornerstone of networking. I think there will be a cascade of confusion as and when the previous hosts file becomes out-of-date.

️

That's a post from back in 2023 and looks like it's not fixed. I think that's exactly happening here too - the already existing records (from ISC) are working and the new ones are not at all.