Cisco Systems 3560 Manual De Usuario

Although the switch does not support Token Ring connections, a remote device such as a Catalyst 5000 
series switch with Token Ring connections could be managed from one of the supported switches. 
Switches running VTP Version 2 advertise information about these Token Ring VLANs:

Token Ring TrBRF VLANs

Token Ring TrCRF VLANs

For more information on configuring Token Ring VLANs, see the Catalyst 5000 Series Software 
Configuration Guide.

Follow these guidelines when creating and modifying normal-range VLANs in your network:

The switch supports 1005 VLANs in VTP client, server, and transparent modes. 

Normal-range VLANs are identified with a number between 1 and 1001. VLAN numbers 1002 
through 1005 are reserved for Token Ring and FDDI VLANs.

VLAN configuration for VLANs 1 to 1005 are always saved in the VLAN database. If the VTP 
mode is transparent, VTP and VLAN configuration are also saved in the switch running 
configuration file.

The switch also supports VLAN IDs 1006 through 4094 in VTP transparent mode (VTP disabled). 
These are extended-range VLANs and configuration options are limited. Extended-range VLANs 
are not saved in the VLAN database. See the 

Before you can create a VLAN, the switch must be in VTP server mode or VTP transparent mode. 
If the switch is a VTP server, you must define a VTP domain or VTP will not function.

The switch does not support Token Ring or FDDI media. The switch does not forward FDDI, 
FDDI-Net, TrCRF, or TrBRF traffic, but it does propagate the VLAN configuration through VTP.

The switch supports 128 spanning-tree instances. If a switch has more active VLANs than supported 
spanning-tree instances, spanning tree can be enabled on 128 VLANs and is disabled on the 
remaining VLANs. If you have already used all available spanning-tree instances on a switch, 
adding another VLAN anywhere in the VTP domain creates a VLAN on that switch that is not 
running spanning-tree. If you have the default allowed list on the trunk ports of that switch (which 
is to allow all VLANs), the new VLAN is carried on all trunk ports. Depending on the topology of 
the network, this could create a loop in the new VLAN that would not be broken, particularly if there 
are several adjacent switches that all have run out of spanning-tree instances. You can prevent this 
possibility by setting allowed lists on the trunk ports of switches that have used up their allocation 
of spanning-tree instances.

If the number of VLANs on the switch exceeds the number of supported spanning-tree instances, 
we recommend that you configure the IEEE 802.1s Multiple STP (MSTP) on your switch to map 
multiple VLANs to a single spanning-tree instance. For more information about MSTP, see