NAC-L2-802.1x with 7940 IP Phones and builtin swithport?

Question

Hi
I've got the NAC Framework, NAC-L2-802.1x working in a test LAB with network hosts (PCs) connected directly to the L2 switch. In our production environment, we have Cisco 7940 IP phones on every desk, and the PCs connect to the switchport on the back of these phones. How would one configure NAC-L2-802.1x to work in a setup like this? I've done quite a bit of searching on Cisco and only found this reference to IP phones and NAC;
IP Telephone and Device Mobility
The computer connected to the PC port on an IP phone will get posture validated successfully.
It does not help much...
Thanks very much.
Jason

Answer 1

You have 2 choices:
1) Ignore the phones based on CDP. You get this be just configuring 802.1X along with a VVID. Here's an example port config from a 3750:
interface GigabitEthernet1/0/2
description endpoints
switchport access vlan 2
switchport mode access
switchport voice vlan 200
srr-queue bandwidth share 10 10 60 20
srr-queue bandwidth shape 10 0 0 0
queue-set 2
mls qos trust device cisco-phone
mls qos trust cos
dot1x pae authenticator
dot1x port-control auto
spanning-tree portfast
spanning-tree bpduguard enable
ip verify source
ip dhcp snooping limit rate 10
The config above will allow a Cisco phone in "for free" just b/c it can do CDP.
2) Authenticate IP phones via 1X or MAC-Authentication for phones that cannot support 1X. This would be the same config as above, with the addition of this line:
dot1x host-mode multi-domain
And if your IP phone cannot do 1X (for example the 7940 cannot) then you'll need to check it's MAC for entry into the network by adding this line:
dot1x mac-auth-bypass
Hope this helps,