Unifi Switch Aggregation RSTP problem

[PenguinMaster]

Hi all--

 

I have a Unifi Switch Aggregation (a layer 2 switch) and am trying to disable RSTP on specific ports on the switch.  These devices are being significantly delayed while connecting to the network because of the RSTP "config time" which happens every time the devices (Windows 11 clients) wake from sleep or turn back on after being shut down.  In my internetworking class that I am taking in college, my professor suggested that I enable spanning-tree port fast which is meant for the Cisco devices we use in class.  Is it possible and how I could do this on my Ubiquiti switch?

 

 

[Alex Atkin UK]

What makes you think its RSTP?  I certainly haven't noticed this problem.

[Lurick]

1 hour ago, Alex Atkin UK said:

What makes you think its RSTP?  I certainly haven't noticed this problem.

I'm going to agree. Although Rapid Spanning Tree by default will go through Discard, Learn, Forward that's usually only 5 to 10 seconds of time. Regular spanning tree is about 45 seconds.

 

OP, Spanning-tree isn't Cisco only though and while it might be called something else config wise setting the ports to access should eliminate this problem all the same on Unifi but someone can correct me on that.

[wseaton]

I tend to agree.

 

I'm curious what is being determined as 'delay' and what layer it is.

 

 

[Smith6612]

On 9/29/2023 at 10:16 PM, PenguinMaster said:

Hi all--

 

I have a Unifi Switch Aggregation (a layer 2 switch) and am trying to disable RSTP on specific ports on the switch.  These devices are being significantly delayed while connecting to the network because of the RSTP "config time" which happens every time the devices (Windows 11 clients) wake from sleep or turn back on after being shut down.  In my internetworking class that I am taking in college, my professor suggested that I enable spanning-tree port fast which is meant for the Cisco devices we use in class.  Is it possible and how I could do this on my Ubiquiti switch?

 

 

Ubiquiti switches have a very short guard timer for spanning tree blocking (in the order of a couple seconds). They don't allow disablement of spanning tree hold timers on a per-port basis like you can on a Cisco... at least in the controller. However, if you only need one VLAN available on a port, try assigning that VLAN to the port as untagged to see if it comes up any faster. Terminology for "Untagged" and "Native" should be universal between Ubiquiti and Cisco in this case.

 

There have been complaints about the latest firmware causing this problem on the Switch Aggregation over at the Ubiquiti forums. Try switching your switch's firmware to something older to see if that helps. Also, try setting the port speeds manually rather than using auto-negotiate. There have been bugs with that too.