Dell 6248 PowerConnect Switch – How to use General Switchport Mode

Tags

, ,


How to use General Switchport Mode on Dell PowerConnect 6248 Switches

I have been using the Dell PowerConnect 6248 switches for about 2 years now and this quick technical post is due to an issue I have when I tried to migrate servers across to a new switch stack using a single link back to the original switch.

Overview

On the Powerconnect switches the General switchport mode consists of a combination of VLAN Trunk and VLAN Access modes that can be marked as both tagged and untagged.

One of the traps is that all untagged frames are sent to the native VLAN (defined using the switchport general PVID XXXX command). All frames sent to a specific VLAN must be tagged. The native VLAN still applies to the General switchport mode.

It is possible to have multiple untagged VLANs on a General link this is done using the command:

switchport general allowed vlan add 10,20,30,40

You can only have one (1) Port VLAN ID (PVID). The PVID represents the native VLAN and is defined using the command:

switchport general PVID XXXX

While untagged traffic may be sent via several untagged VLANs, returning untagged traffic will only be received by the PVID and therefore will NOT be forwarded to a specific VLAN.

The PowerConnect 62xx series switches must use General mode if you want to allow management traffic onto the switch over the PVID. If you use Trunk mode, you will not have the default VLAN on those ports. The ports will only allow tagged traffic.

Available Commands

Command Description
switchport mode general Sets the port type to an 802.1Q VLAN. An 802.1Q VLAN port will allow multiple tagged VLANs.
switchport general allowed vlan add 101, 102, 310 tagged Sets the port to allow only tagged traffic in VLANs 101, 102, 310. Traffic with tags other than 101, 102, 310 will be dropped.
switchport general allowed vlan add 200 Sets the port to allow VLAN 200 traffic out the port as untagged. Any untagged traffic coming into the port would be pushed to the native PVID set on the port.
switchport general pvid 1 Sets the port to put any untagged packets entering the port into VLAN 1.
switchport general allowed vlan remove 1 Used to remove the port membership from VLAN “1”. By default all the port on the switch are members of VLAN “1”.
switchport general pvid 4095 Sets the port to put any untagged packets entering the port into VLAN 4095 (4095 is the discard VLAN. Setting the PVID to 4095 means that untagged packets are not allowed on this port).
switchport general acceptable-frame-type tagged-only Discards untagged frames at ingress.

Examples of the Commands in use

console# configure
console(config)# interface ethernet 1/g1
console(config-if)# switchport mode general
console(config-if)# switchport general allowed vlan add 100 tagged
console(config-if)# switchport general allowed vlan add 200 untagged
console(config-if-1/g1)#switchport general pvid 1
console(config-if)# exit

Note:
If you insert the command “switchport general allowed vlan add 600″ without specifically stating tagged or untagged the default value is untagged.

Saving your changes

You must save your changes to survive a power restart. Use the ‘copy’ command:

copy running-config startup-config