Troubleshooting guide

Table Of Contents
274
3300 ICP Technician’s Handbook
applies to untagged and VLAN 1 tagged packets only; voice VLAN
tagging is always preserved.
IP Routing form
- When the CXi/CXi II/MXe receives a packet from a host on the
LAN, it checks the table. If a route is found on the Network List, the
CXi/CXi II/MXe/AX forwards the packet to the system Gateway or
a router connected to the local subnet. If no route is found, the
CXi/CXi II/MXe/AX forwards the packet to the internet through its
WAN interface.
CXi/CXi II/MXe/AX VLAN Behavior
Default VLAN 1
- When the CXi/CXi II/MXe/AX is on the default VLAN, it accepts
untagged frames and tagged VLAN 1 frames. Any non-VLAN 1
tagged frames are dropped. The CXi/CXi II/MXe/AX treats
untagged frames as VLAN 1 frames. The CXi/CXi II/MXe/AX
prioritizes traffic based on the priority tag.
- The CXi/MXe have two priority queues, low (0-3) and high (4-7).
The AX has four priority queues. By default untagged frames are
placed in the low priority queue. Tagged frames are prioritized
according to their priority tagging. On egress, all traffic on all ports
is untagged with the exception of port 17 on the CXi/CXi II and the
two LAN ports on the MXe, MXe Server and the AX, where the user
has the option to tag VLAN1 traffic via the "Tag VLAN 1 on Trunk
Port" parameter.
Voice VLAN
- When the CXi/CXi II/MXe/AX is programmed with a Voice VLAN,
the switch will allow untagged frames and tagged VLAN 1 frames
as well as Voice VLAN frames. All other VLAN tagged frames will
be dropped. The priority of tagged frames are preserved and
queued accordingly. On egress, Voice VLAN traffic is either tagged
on all ports (prior to Release 9.0) or configured as tagged or
untagged on a port-by-port basis (Release 9.0 and later). Untagged
frames are treated as VLAN 1 and forwarded to an external layer 2
switch.
- CXi/CXi II: When the phones are on the Layer 2 switch of the
CXi/CXi II, the phones and the CXi/CXi II switch must be on the
same the Voice VLAN for the phones to communicate with the Call
Control.