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cisco:vlans
Table of Contents
VLANs
- Commands
- show vlan internal usage
- show vlan
- Overview of VLANs
- Breaks up collision domains into multiple broadcast domains
- Layer 3 switches allow VLANs to communicate with each other
- VTP version 3 updates do not pass through promiscuous trunk ports.
- VLAN Configuration Guidelines and Restrictions
- Prior to creating a VLAN, the switch must be in either VTP server or VTP transparent mode
- In order to use VTP server mode, the VTP domain name must be prior defined
- VLANs are organized into three ranges:
- Reserved
- Normal
- Extended
| VLANs | Range | Usage | Propagated by VTP |
|---|---|---|---|
| 0, 4095 | Reserved | For system use only. You cannot see or use these VLANs. | N/A |
| 1 | Normal | Cisco default. You can use this VLAN but you cannot delete it. | Yes |
| 2-1001 | Normal | Used for Ethernet VLANs; you can create, use, and delete these VLANs. | Yes |
| 1002-1005 | Normal | Cisco defaults for FDDI and Token Ring. You cannot delete VLANs 1002-1005 | Yes |
| 1006-4094 | Extended | For Ethernet VLANs only. When configuring extended-range VLANs, note the following: 1. Layer 3 ports and some software features require internal VLANs. Internal VLANs are allocated from 1006 and up. You cannot use a VLAN that has been allocated for such use. To display the VLANs used internally, enter the show vlan internal usage command. 2. Switches running Catalyst product family software do not support configuration of VLANs 1006-1024. If you configure VLANs 1006-1024, ensure that the VLANs do not extend to any switches running Catalyst product family software.You must enable the extended system ID to use extended range VLANs. | No |
- Configurable Normal-Range VLAN Parameters
- Note: VLANs 1 and 1006-4094 use only default values.
- You can configure the following parameters for VLANs 2-1001:
- VLAN name
- VLAN type
- VLAN state (active or suspended)
- SAID
- STP type for VLANs
- VLAN Default Configuration
- Ethernet VLAN Defaults and Ranges
| Parameter | Default | Valid Values |
|---|---|---|
| VLAN ID | 1 | 1-4094 |
| VLAN name | VLANx, where x is a number assigned by the software. | No range |
| 802.10 SAID | 100,001 | 1-4,294,967,294 |
| MTU size | 1500 | 1500-18,190 |
| Translational bridge 1 | 1002 | 0-1005 |
| Translational bridge 2 | 1003 | 0-1005 |
| VLAN state | active | active; suspend; shutdown |
- Configuring VLANs
- Stored in vlan.dat file
- Configuring VLANs in Global Configuration Mode
- When the switch boots, if the VTP domain name and VTP mode in the startup-config and vlan.dat files don't match, the switch uses the configuration in the vlan.dat file.
cisco/vlans.txt · Last modified: by 127.0.0.1
