Static Virtual LANs (VLANs)

Port-Based Virtual LANs (Static VLANs)

During a Telnet session to the switch, if you configure the Management-

 

 

 

VLAN to a VID that excludes the port through which you are connected

 

 

 

to the switch, you will continue to have access only until you terminate

 

 

 

the session by logging out or rebooting the switch.

 

 

 

 

 

During a Web browser session to the switch, if you configure the Manage-

 

 

 

ment-VLAN to a VID that excludes the port through which you are

 

 

 

connected to the switch, you will continue to have access only until you

 

 

 

close the browser session or rebooting the switch.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

N o t e

 

The Management-VLAN feature does not control management access through

 

 

a direct connection to the switch’s serial port.

 

 

 

 

 

Enabling Spanning Tree where there are multiple links using separate

 

 

 

 

 

VLANs, including the Management VLAN, between a pair of switches,

 

 

 

Spanning Tree will force the blocking of one or more links. This may

 

 

 

include the link carrying the Management VLAN, which will cause loss of

 

 

 

management access to some devices.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VLAN 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VLAN 40

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Switch

 

 

Switch

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VLAN 20 (Management VLAN)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VLAN 1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

VLAN 20 Only

 

 

 

 

VLAN 40

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

(Management VLAN)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Blocked

 

 

 

 

Even though the ports on the Management VLAN link between Switch 1 and Switch 2 do not belong

 

 

 

to the other VLANs connecting the two switches, enabling Spanning Tree will block one of the two

 

 

 

links. This is because Spanning Tree operates per-switch and not per-VLAN.

 

 

 

 

 

Figure 2-27. Example of Inadvertently Blocking a Management VLAN Link by

 

 

 

 

 

 

 

 

 

 

Implementing Spanning Tree

 

 

 

2-37