QoS Blocking All with No Policies Defined

[mjgrossman]

Hello All,

We are configuring a new small/medium sized network, and saved QoS configuration/tailoring for last.

We applied some of "standard" QoS policies from previous system designs and were having communication problems, so I started backing out all QoS policies one at a time to try and quickly locate the problem child.

I have now backed out all QoS settings - and cannot talk to anything external to the switch (mainly testing with RADIUS authentication and pings to the RADIUS servers). My QoS configuration currently looks like this:

! QOS:
qos log console
qos apply

If I disable QoS (qos disable), I can talk to everything normally. As soon as it is re-enabled, I lose all communication. I was operating under the assumption that if no policy conditions/actions/rules are configured, QoS will not block traffic (traffic has to meet a condition or no QoS rules are applied - right?).

Am I misunderstanding something fundamental?

Thank you in advance!!

[silvio]

very strange - if this is the running config (show configuration snapshot qos). Maybe there is an issue in the firmware (but never heard) - than use the newest release. Also you can try to factory reset (if possible) your switch (rm vc*) and after reboot put all the other configuration into the switch.... and than step by step your qos configs.....
If this doesn't help or is not possible you need to open a ticket at ALE.
best regards
Silvio

[mjgrossman]

Thank you for the reply Silvio.

We're running 8.7.252.R02 - I'll check to see if a later revision is available and try applying that. I'll also try the factory reset.

The only other modification we've made that I can think of which may be related is we've enabled Joint Interoperability Test Command (JITC) Mode, but I do not see anything in the manual related to changes in QoS behavior with that enabled.

[silvio]

i hope you will find the reason and solve it.

[mjgrossman]

We were able to confirm that JITC Mode is definitely causing the issue. With JITC Mode disabled, our QoS policies work fine.

Once JITC Mode is enabled and the switch rebooted, enabling QoS prevents all traffic to/from the switch.

We opened a ticket with ALE support last week, waiting for input. Will post an update once we have more info or resolution.

[silvio]

very interesting - good to know. I think the JITC mode is seldom used ...