ubiquiti and dhcp

[browolf]

Even after turning spanning tree off we've still got wierd dhcp problems. re: http://www.edugeek.net/forums/wired-networks/199307-ubiquiti-spanning-tree.html

 

Random classroom computers say no logon servers available. My test laptop beside me with /release and /renew takes from 20seconds to several minutes to get a new ip.

 

We've just discovered another situation which might be related whereby whatever switch the internet uplink is plugged into, in the cloud controller, that switch shows it's uplink to be 100mb, even though it has a 1GB uplink to the main XG

 

Situation with internet plugged in

 

[ATTACH=CONFIG]50205[/ATTACH]

 

If we unplug the internet the 1gb FDXs revert to 10GB links and 10mb uplink goes away.

 

Any ideas?

 

 

EDIT: this seems possible to solve the dhcp problem at least: https://community.ubnt.com/t5/UniFi-Routing-Switching/Disable-DHCP-Snooping-on-USW/td-p/1510229

Edited September 13, 2018 by browolf

[forkies]

We have had some similar issues, we reverted to an older firmware but that had some other issues. I ended up upgrading to latest firmware, restarting the switches, force provisioning and then rebooting again and so far haven’t had any issues apart from one switch saying a WiFi point was an uplink which hasn’t changed back even when the port was disabled for hours. Network is working fine now just the interface having a winge now.

[forkies]

Sorry should have said, when we tested the common factor was the 16XG, if an uplink went through it we had issues with the switches below it, but put the uplink bypassing the 16XG into the core and it was fine.

[browolf]

Upgraded the cloud controller and now a bunch of ports that were fine before, now report RX faults.

 

[ATTACH=CONFIG]50239[/ATTACH]

[browolf]

I didn't explicitly say how the problem with DHCP got solved.

 

There's a bug in the unifi switches that whereby when DHCP guard is off, there's some part of it that is still on and that part is still checking dhcp packets and randomly dropping them.

 

So turning DHCP guard on and specifying our dhcp servers magically fixed the problem.

[PotNoodleTech]

 

So turning DHCP guard on and specifying our dhcp servers magically fixed the problem.

 

Great work mate!!