Connection Problem for some devices

ojosaghae

Hi everyone. I need your help.
We have been using KEA DHCP for a while now.. and it worked well. Suddenly I noticed last week that we were experiencing intermittent downtime. For no reason.
My DHCP pool is large - I use a /20 subnet which is over 4000 IP addresses(our total devices comes close - ~3800).
On checking the status logs, I noticed a set of recurring alerts:

Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_lan_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt3_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt4_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt5_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt6_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt7_0 evaluated to 1
Aug 12 17:06:39 kea-dhcp4 73677 INFO [kea-dhcp4.dhcpsrv.0x3b1902018900] EVAL_RESULT Expression pool_opt1_0 evaluated to 1

We are a predominantly macOS company - all our laptops are MacBooks. Some macbooks disconnect with the wifi-and-exclamation-mark icon showing, then connect by themselves, while some are steadily connected.
My iPhone is not connected at all, but my android phone does (after showing couldn't get ip address for a while).

I have this Internet Connection Monitor extension installed on my Chrome browser. It shows offline, but I am browsing just fine.

Any pointers in the right direction will be most appreciated, please.

Gertjan

@ojosaghae

Do the usual test :
Renew the lease on on your device : did it get a lease ? (network, gateway, DNS and IP ?)
At the same time, check the DHCP log in the pfSense GUI : did you see your device (you can recognize your device with the MAC) renew the lease ?

If issues :
Restart Kea.
Still issues : switch to ISC ?!

ojosaghae

@Gertjan Thanks for your response.
I did the renew DHCP lease. In the logs, I found the below:

Aug 14 08:28:02	dhcpd	80893	reuse_lease: lease age 804 (secs) under 25% threshold, reply with unaltered, existing lease for xx.xx.xx.xx
Aug 14 08:28:02	dhcpd	80893	DHCPREQUEST for xx.xx.xx.xx from aa:bb:cc:dd:ee:ff  (MacBookPro) via igb1
Aug 14 08:28:02	dhcpd	80893	DHCPACK on xx.xx.xx.xx to aa:bb:cc:dd:ee:ff (MacBookPro) via igb1

DHCP works well, apparently.

Switch to ISC? Done. Still the same issue, but it is far better than when it was on KEA.

Restart KEA? Maybe after work hours. I'll do that and revert.

Thanks once again

ojosaghae

Hi @Gertjan. I'm back.
The issue, sadly, isn't solved yet.
It pops up a Screenshot 2024-08-15 at 10.31.17.png from time to time. No (obvious) reason. After some minutes, it connects again.
I checked the logs and all I see that has to do with my device are the following entries:

Aug 16 13:09:16	dhcpd	42527	reuse_lease: lease age 352 (secs) under 25% threshold, reply with unaltered, existing lease for 10.21.78.84
Aug 16 13:09:16	dhcpd	42527	DHCPREQUEST for xx.xx.xx.xx from aa:bb:cc:dd:ee:ff (client-MBP-2) via igb1
Aug 16 13:09:16	dhcpd	42527	DHCPACK on xx.xx.xx.xx to aa:bb:cc:dd:ee:ff (client-MBP-2) via igb1

It repeats this between 5 - 7 seconds intervals.

Uglybrian

Out of cuirosiy, what access points are you using? Is this problem happing with wired and wireless clients?

Gertjan

@ojosaghae said in Connection Problem for some devices:

It pops up a Screenshot 2024-08-15 at 10.31.17.png from time to time.

That's nasty and probably means : radio wave issue.
As we humans can see these waves, we can't see interference, collisions, leaking micro waves and things like that.
And its not because we can't see it, it isn't there.

The logs that follow is normal and correct : as soon as the connection comes back up, the wifi device starts with negotiating a DHCP lease. The same thing happens when you disconnect a wired device : when putting the cable back in place, DHCP kicks in first.
Do this ten times a minute, and this will happen ten times a minute.

The thing is : this could have a lot of causes ...

If your AP has a 'scan' mode, use it to see if there are other SSID's around using the same frequency.
Or de activate all your wifi stuff, and activate them one by one. In between, test for a while.
As soon as things go down hill, you've found the device acting bad : remove it permanently.
Or look a the zillion "My wifi is bad, what can I do ?" youtube videos