On (2013-04-30 13:01 +0700), Victor Sudakov wrote: > In Wireshark I can see that some packets generated by the switches > themselves have some non-default CoS values. E.g. OSPF hello packets > and PIM messages have the cos value of 6 in the 802.1Q header, STP > frames have the value of 7 etc etc. > > Why does this happen and where is it documented?
This is canonical use of CoS/Prec values. 7 is network control, 6 is internetwork control. This is not exactly what you're looking for, as it's probably auto-qos specific: http://www.cisco.com/en/US/docs/switches/lan/catalyst3750x_3560x/software/release/12.2_55_se/configuration/guide/swqos.html#wp1738472 It's not very good idea to implement QoS without some idea of your goals. At very least you should decide how many classes you need to discriminate your traffic into (the fewer you can live with, the better, if you're not running QoS now, 2 might be prudent) Especially in small Catalysts just turning MLS QoS on pretty much invariably makes your life worse than what it was. This is must-read document for surviving 3560/3750 QoS, I'm hoping good deal of it is valid in X world, but I don't know for sure: https://supportforums.cisco.com/docs/DOC-8093 -- ++ytti _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
