Cisco Support Community
Showing results for 
Search instead for 
Did you mean: 

Attention: The Cisco Support Community site will be in read only mode on Dec14, 2017 from 12:01am PST to 11:30am for standard maintenance. Sorry for the inconvenience.

New Member

Filtering control packets on port

Good day, folks.

Recently i red document Port ACLs (PACLs) and VLAN ACLs (VACLs) which is the part of Catalyst 6500 Software Configuration Guide and noticed there following:

The PACL feature does not affect Layer 2 control packets received on the port.

but previosly i red in Petr Lapukhov blog (one of posters) folowing:

The IEEE STP BPDUs are sent to IEEE reserved multicast MAC address  “0180.C200.0000” using IEEE 802.2 LLC SAP encapsulation with both SSAP  and DSAP fields equal to “0×42”. (By the way, for the purpose of Layer2  filtering, IEEE BPDUs could be matched using a MAC ACL with LSAP value  of ”0×4242”).

And now im a bit confused - STP BPDUs is not control traffic or Layer2 filtering meaned in Petr blog is not PACL (but what then - VACL???) ?

If smb can clarify those question i will higly appreciate this.

CreatePlease to create content