Why IP phones mac address are learned by the DATA vlan on each port ?

[ferdo]

Hi,

On my 5130, I configured 2 vlans : DATA (180) and TOIP (178).
Below the config of my ports.

#
interface GigabitEthernet1/0/1
description *** VLAN VOICE/DATA ***
port link-type hybrid
undo port hybrid vlan 1
port hybrid vlan 178 tagged
port hybrid vlan 180 untagged
port hybrid pvid vlan 180
undo voice-vlan mode auto
broadcast-suppression 20
multicast-suppression 20
stp edged-port
lldp tlv-enable med-tlv network-policy 178
qos apply policy voippolicy inbound
poe enable
loopback-detection enable vlan 1 to 4094
loopback-detection action shutdown

#
interface GigabitEthernet1/0/2
description *** VLAN VOICE/DATA ***
port link-type hybrid
undo port hybrid vlan 1
port hybrid vlan 178 tagged
port hybrid vlan 180 untagged
port hybrid pvid vlan 180
undo voice-vlan mode auto
broadcast-suppression 20
multicast-suppression 20
stp edged-port
lldp tlv-enable med-tlv network-policy 178
qos apply policy voippolicy inbound
poe enable
loopback-detection enable vlan 1 to 4094
loopback-detection action shutdown
#
But I do not understand why on each port, the IP phones mac-address are also learned by the DATA vlan.

<VCN-SW-05>dis mac-address interface GigabitEthernet 1/0/1
MAC Address VLAN ID State Port/NickName Aging
0800-0f5c-c18e 178 Learned GE1/0/1 Y
0800-0f5c-c18e 180 Learned GE1/0/1 Y <= IP phone mac-address 0800-0f5c-c18e is learned by DATA vlan 180
507b-9d3b-dcbb 180 Learned GE1/0/1 Y
<VCN-SW-05>dis mac-address interface GigabitEthernet 1/0/2
MAC Address VLAN ID State Port/NickName Aging
0800-0f5c-8eb9 178 Learned GE1/0/2 Y
0800-0f5c-8eb9 180 Learned GE1/0/2 Y<=IP phone mac-address 0800-0f5c-8eb9 is learned by DATA vlan 180
7446-a091-af4e 180 Learned GE1/0/2 Y
<VCN-SW-05>

Need help please.

Regards

Ferdo

[VoIP-Buddy]

Ferdo,

What phones are you using?

My guess is that when they first boot up, they go on the data VLAN until the phone starts tagging it's VoIP traffic.  The MAC Address should age out on VLAN 180 eventually.

Do the phones actually make it onto the Voice VLAN after they restart?

Regards,

David

[ferdo]

Hi David,
Thank you for your reply.
My phones are Mitel.
I agree that when phones start for the first time, they go on data VLAN until the phone starts tagging it's VoIP traffic.

But MAC addresses are not age out on VLAN 180.

What is the default age out time ?
And can this situation affect my network ?

I do not really understand your last question  "Do the phones actually make it onto the Voice VLAN after they restart ?"

Regards

Ferdo

[Vince-Whirlwind]

Your phones are making it onto the Voice VLAN, good.

Here is what I would try:

1/ Try a switchport config that is 
port link-type trunk
port trunk vlan 178 tagged
port trunk vlan 180 untagged
Instead of "hybrid"

2/ try adding the command 
voice vlan 178 enable

[Vince-Whirlwind]

Having said that, the phone *is* connected at Layer2 to both VLANs, so it makes sense that should see its MAC.

[ferdo]

Hi Vince,

Thank you for your reply.

I agree to set the command "voice vlan 178 enable", but not to set all my ports in "Trunk" mode.
But the fact that mac addresses of IP phones are learned by the Data Vlan and remain permanently in the mac table of each port, is there any problem ?

Is not there any age out time, so that the mac table of each port contains only the mac address of the phone learned in the voice vlan and the mac address of the PC learned in the data vlan ?

Thank you for your help.

Regards

Ferdo

[Vince-Whirlwind]

The phone is attached to your network in both VLANs. The PC is attached to the phone on one VLAN.

The segment comprising VLAN180 has in it:
-switch
-phone
-PC

The segment comprising VLAN178 has in it:
-switch
-phone

[ferdo]

Hi Vince,

Thank you for your reply.

You answered my question, but not explicitly.
Do you mean that the fact that ip phones mac addresses are learned in the data vlan (180)  permanently will not cause any problem in the network ?

Regards

Ferdo

[KennyP]

GOOD MORNING!!! 

I'm not having that issues with a phone showing up in a data vlan and voice vlan at the same time. 

dis mac-address int gi1/0/35

MAC ADDR VLAN ID STATE PORT INDEX AGING TIME(s)
c8d3-ff77-e156 20 Learned GigabitEthernet1/0/35 AGING
4001-7a2b-97a7 910 Learned GigabitEthernet1/0/35 AGING

Here is my current config:
interface GigabitEthernet1/0/35
port link-type hybrid
undo port hybrid vlan 1
port hybrid vlan 910 tagged
port hybrid vlan 20 untagged
port hybrid pvid vlan 20
undo voice vlan mode auto
voice vlan 910 enable
loopback-detection enable
loopback-detection action shutdown
bpdu-drop any
poe enable
stp edged-port enable
lldp compliance admin-status cdp txrx <---(We're using Cisco phones)
dot1x re-authenticate
undo dot1x handshake
dot1x port-method portbased

Setting them up as a trunk worked but it was a security risk we're wren't really to take. WE came up with this config and it's been working fine since then.