Correct configuration for PC port to work with MAC Auth

ITSP

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Hi,

Our switches have MAC authentication enabled so that only authorized devices can connect to the network. In some offices, we only have 1 network port available and it's difficult to lay new cables in due to several issues, so we end up connecting the Yealink T31G's WAN port to the wall and then connect the desktop to the Yealink's PC port. We then configure in 3CX under Advanced, the VLAN IDs for each port (70 for WAN 121 for PC). We do register the MAC of both the PC and the Yealink.

Problem is, there doesn't seem to be a consistent way that the MACs are assigned the VLAN on the switch. Sometimes the PC's MAC address gets assigned VLAN 70 instead of VLAN 121. Sometimes, both the phone and PC are assigned the same VLAN, sometimes the same MAC address gets assigned different VLANs.

1770709815065.png

What's the correct way to configure this so that it works?
 
In this case you might need to proceed with VLAN in the ip phone configuration as explained here.
 
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I have tried every combination of that but no luck.

I am guessing that part of the problem is that the switch (Ruckus ICX) assigns the VLAN based on the MAC it sees first (as expected):

1. Phone boots up, sends the phone's MAC out to the switch port by requesting DHCP
2. Switch sees the phone's MAC, checks its database and sees that that MAC should belong to voice VLAN and assigns that VLAN to the switch port
3. Phone receives DHCP IP on voice VLAN, boots up
4. Phone forwards packets from PC with PC's MAC address to switch port
5. Switch sees the PC's MAC, checks its database and sees that that MAC should belong to data VLAN and assigns that VLAN to the switch port

All good in theory except when booting up the phone, sometimes the PC's MAC is the first one to be seen by the switch for some reason.

Will need to do more investigation to see why Yealink phones do this. The Polycoms are working fine.

If anyone has seen this before in their environment and has some ideas to fix. Appreciate if you could share it.
 

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