What is the difference between VLAN subinterface and Ethernet subinterface?

[Alen Danielyan]

Hi!

I want to know what is the difference between VLAN subinterface and "Ethernet subinterface"?

What I understand under VLAN subinterface: it is a logical interface I create over L2 physical port of built-in switch on my Cisco router (e.g. 870, 1811) to make it function like L3 interface.

What I understand under VLAN subinterface: this term is from: "Applying QoS Features to Ethernet Subinterfaces" document.

Thank you.

[cadet alain · Accepted solution]

Hi,

AFAIK the ethernet subinterfaces are the logical interfaces used on a router to trunk with a switch or a host/server with multiple VLANs

.

Regards.

Alain.

[Latchum Naidu]

Hi Alen,

Vlan subinterfaces??
If talking about a multilayer switch device, you can transform a layer 2 switching interface into a layer 3 only router interface, and give it also an ip address, or create subinterfaces each with its own ip address or subnet, within the same physycal interface, so the entire physical port is a trunk port, maybe connected to another switch swith some vlans.

Vlan Interfaces are the traditional software interfaces created in the switch

An Ethernet subinterface is a logical interface in Cisco IOS.

Hope this clear you.

Please rate the helpfull posts.
Regards,
Naidu.

[Nathan Spitzer]

Just FYI: Using L3 subinterfaces like you describe is a great technique for integrating Cisco and non-Cisco switches at layer-2 where you either can not or do not want to run MST. A lot of time there are idiosyncrasies that make true integration of the spanning-tree domain problematic and this technique can work where the Cisco is the default GW for all the VLANS but the VLANS are hosted on non-Cisco switches.

[Alen Danielyan]

cadetalain wrote:
Hi,
AFAIK the ethernet subinterfaces are the logical interfaces used on a router to trunk with a switch or a host/server with multiple VLANs
.
Regards.
Alain.

Hi, Alain!

Thank you for your answer. It is quite clear and understandable. Hope your AFAIK it is correct.

[cadet alain]

Hi Alen,

Thank you for your answer. It is quite clear and understandable. Hope your AFAIK it is correct. 

I hope so

Regards.

Alain.