Linksys SRW switch port commands equivalent for Cisco?

craigvoice · ‎06-05-2008

My Linksys SRW switch has the following 3 modes. Is it correct that Cisco 3xxx has only 2 access and trunk? I can't find a translation for General setting.

-General. The port belongs to VLANs, and each VLAN is user-defined as tagged or untagged (full 802.1Q

mode).

-Access. The port belongs to a single untagged VLAN. When a port is in Access mode, the packet types

which are accepted on the port (packet type) cannot be designated. It is also not possible to enable/

disable ingress filtering on an access port.

-Trunk. The port belongs to VLANs in which all ports are tagged (except for an optional single native VLAN).

jamesl0112 · ‎06-05-2008

The three standard Cisco switchport modes are:

access Set trunking mode to ACCESS unconditionally

dynamic Set trunking mode to dynamically negotiate access or trunk mode

trunk Set trunking mode to TRUNK unconditionally

What exactly are you trying to achieve? For instance, are you trying to block untagged VLANs, or certain VLANs, or... just wondering?

A dot1q trunk will assume untagged traffic is for the native VLAN.

You can prevent traffic for VLAN x from traversing a trunk to another switch that does not have VLAN x configured by using VTP pruning.

S(config)#vtp pruning

You can also configure which VLANs are allowed on the trunk -

S(config-if)#switchport trunk allowed vlan x-y,z

Ryan Carretta · ‎06-05-2008

The Cisco can support these modes and more -

* access - accept only untagged frames in the access vlan

* trunk - accept tagged frames in the 'trunk allowed' vlans. Untagged frames will be received in the native vlan

* dot1q-tunnel - tunnel 802.1q frames across a cloud, retaining their original tagging

* private-vlan - set up a private vlan port

* dynamic - passively or actively try to establish a trunk via DTP.

craigvoice · ‎06-05-2008

What is the difference between untagged and tagged frames?

The Linksys switch is attached to 2800 Cisco router ethernet port where I created sub-interfaces for dot1q trunk. I created vlan 1 native and vlan 2. (Router on a stick)

In a Cisco 3560 switch I would put the port in "switchport mode trunk", but in the Linksys I'm not sure if it should be in "General" or "Trunk" mode. (I know it is not "Access" because in Linksys terms that is only 1 vlan).

Thanks.

Rajat Chauhan · ‎06-05-2008

Craig,

The difference is literal, really. The tagged frames has a VLAN_ID tag to be identified from within the trunk carrying multiple vlans, whereas native vlan or untagged frames are not tagged, to maintain compatibiltiy with the devices that do not understand tags.

It should e "trunk" on Linksys side as well.

HTH

Raj