Intermittent Connectivity Issues w/DOT1X MDA

[rcullum]

Hi, Just as a side question, but what ip device tracking global command did you use? I have a network with Mitel 5320 phones and they are not responding to device tracking arps. I suspect they dont like source 0.0.0.0 but wanted to know if you have seen similar for this phone?

[Terence Lockette]

I don't recall using any global config commands.  I only have the commands applied to the interfaces.  If I did use global commands, I may have removed them during my tshoot sessions and never put them back in.

[dawid.karol.bednarczyk]

if your subnet in the vlan is 192.168.1.0/24 

and you sue command :

ip device tracking probe auto-source fallback 0.0.0.6 255.255.255.0 override

arp probe will be send with ip 192.168.1.6 

note how dangerous it is if you put 0.0.0.1 and this 192.168.1.1 is your gateway ( all clients will learn that mac for 192.168.1.1 is mac address of l2 port on the switch and traffic will be lost )

if you use:

ip device tracking probe auto-source fallback 0.0.0.0 255.255.255.0 override

probes will be sent with 0.0.0.0 ip 

Confirmed with packet captures.

We have a case for this because this bring some issues 

- since this command is global it applies to all vlans, it is not guaranteed that you have ip X free in each subnet on access swithc

- since this command defines some fixed mask , strage things happens for smaller subnets , like in this example 192.168.1.32/28 

For your case though it might be ok to sue this command in case your phones ignore 0.0.0.0