Troubleshooting guide
Troubleshooting Guide
74
TFTP Fail
(Remote IP phone 
(statically programmed IP 
address) cannot access 
MN3300 across WAN).
The Layer 2 switch port for the 
phone interface is shut down or 
not configured properly.
1. Check the Layer 2 switch and ensure that 
the port is not shut down (see “Network 
Configuration Examples” in the “Typical 
Network Configurations” chapter of the MCD 
Technician’s Handbook for more 
information).
2. For a Cisco Layer 2 switch: verify that this is 
a trunk port with Dot1q encapsulation, and 
ensure this trunk port allows both native and 
voice LAN to pass through.
3. For an HP Layer 2 switch: verify that Native 
Lan is untagged and Voice Lan is tagged.
The Layer 2 switch port for router 
interface is shut down or not 
configured properly.
1. Verify which configuration you have (see 
“Network Configuration Examples” in the 
“Typical Network Configurations” chapter of 
the MCD Technician’s Handbook for more 
information).
2. Ensure the port(s) on both sides (Layer 2 
switch and router) are not shut down.
3. If there is physical interface on the router for 
each VLAN, make sure that the Layer 2 
switch is set to access the port for the 
corresponding VLAN/subnet correctly; OR
If this is a router on a switch, verify that this 
is a trunk port on L2 switch, and ensure this 
trunk port allows both native and voice LAN 
to pass through.
4. On the router's sub-interface, verify that the 
proper VLAN is associated to the 
sub-interface (see “Network Configuration 
Examples” in the “Typical Network 
Configurations” chapter of the MCD 
Technician’s Handbook for more 
information)).
(Cont’d) Typo in IP address, VLAN ID, 
gateway.
1. Delete and reprogram the static IP address. 
If there is no VLAN or priority, leave them as 
blank.
2. Verify that the gateway IP address is correct.
Table 18: IP Phone Registration Troubleshooting
Error Message on 
Display
Possible Cause Corrective Action
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