Troubleshooting guide

Hardware
71
(Cont’d) The L2 switch port for the phone
interface is shut down or not
configured properly.
1. Check the L2 switch and ensure that the port
is not shut down.
2. For a Cisco L2 switch, ensure that this is a
trunk port with Dot1q encapsulation, and that
this trunk port allows both native and Voice
LAN to pass through.
3. For an HP L2 switch, ensure that Native Lan
is untagged, and that Voice LAN is tagged.
4. Verify whether there are two physical
interfaces to the router (one per VLAN), or a
router on a stick configuration (one physical
with virtual sub-interfaces).
5. Ensure that the ports on both sides (L2
switch and router) are not shut down (See
“Network Configuration Examples” in the
“Typical Network Configurations” chapter of
the MCD Technician’s Handbook).
6. If there is a physical interface on the router
for each VLAN, make sure that the L2 switch
is set to correctly access port for the
corresponding VLAN/ subnet.
7. If there is one physical interface on the router
for multiple VLANs, ensure that this is a trunk
port on the L2 switch, and ensure that this
trunk port allows both native and voice LAN
to pass through.
8. On the router sub-interface, ensure that the
proper VLAN is associated to the remote
sub-interface.
Table 18: IP Phone Registration Troubleshooting
Error Message on
Display
Possible Cause Corrective Action
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