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

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. And see here for current known issues.

Bronze

Voice Vlan = trunk + BPDUGuard?

I haven't sniffed the data yet to see what's going on - but it's my understanding that the "switchport voice vlan" command works in conjunction with CDP. When a phone is detected, the switch establishes a 'lite' trunk with the phone, passing both voice and data VLANs.

Is this trunk maintained without any BPDUs? How does that work, exactly?

If I have BPDUGuard on my access ports, does it just 'ignore' bpdu's related to Voice-VLAN related trunks, or does this trunk really exist without BPDUs?

if so... how?

1 REPLY
Silver

Re: Voice Vlan = trunk + BPDUGuard?

BPDU can only be received on a port existing on the trunk. If a BPDU is received on a VLAN that is not configured on the trunk/voice port, it will be dropped and will not trigger bpduguard.

420
Views
0
Helpful
1
Replies