Vlan Configuration Guidelines And Restrictions - Cisco Catalyst 4500 Series Software Configuration Manual

Chapter 17 Configuring VLANs, VTP, and VMPS
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When the software translates from one VLAN type to another, it requires a different VLAN number for
Note
each media type.

VLAN Configuration Guidelines and Restrictions

Follow these guidelines and restrictions when creating and modifying VLANs in your network:
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VLAN Ranges
You must enable the extended system ID to use 4094 VLANs. See the
Note
section on page
With Cisco IOS Release 12.2(31)SGA and later, Catalyst 4500 series switches support 4096 VLANs in
compliance with the IEEE 802.1Q standard. These VLANs are organized into three ranges: reserved,
normal, and extended.
Some of these VLANs are propagated to other switches in the network when you use the VLAN
Trunking Protocol (VTP). The extended-range VLANs are not propagated, so you must configure
extended-range VLANs manually on each network device.
Table 17-1
Table 17-1
VLANs
0, 4095
1
2–1001
VLAN number to use when translating from one VLAN type to another
Before creating a VLAN, put the Catalyst 4500 series switch in VTP server mode or VTP
transparent mode. If the Catalyst 4500 series switch is a VTP server, you must define a VTP domain.
For information on configuring VTP, see the
You cannot use the end command in VLAN database mode.
You cannot use Ctrl-Z to exit VLAN database mode.
If a Catalyst 4948 switch running MSTP and configured with all possible VLANs (4094) is in the
path of two HSRP peers with the timeout set below 500 ms, HSRP flaps.
Workarounds:
Use fewer VLANs.
–
Set the timers greater than 600 ms.
–
Enter the no igmp snooping (globally) and access-list hardware capture mode VLAN
–
commands
23-2.
describes the uses for VLAN ranges.
VLAN Ranges
Range Usage
Reserved For system use only. You cannot see or use these VLANs.
Normal Cisco default. You cannot delete this VLAN.
Normal Used for Ethernet VLANs; you can create, use, and delete
these VLANs.
Catalyst 4500 Series Switch, Cisco IOS Software Configuration Guide - Cisco IOS XE 3.9.xE and IOS 15.2(5)Ex
"VLAN Trunking Protocol" section on page
"Understanding the Bridge ID"
VLANs
17-7.
Propagated
by VTP
—
Yes
Yes
17-3