cancel
Showing results for 
Search instead for 
Did you mean: 
cancel
218
Views
0
Helpful
5
Replies

Why a Pure L2 Switch i.e 2950 has interface loopback option?

Ahmed Mukhtar
Beginner
Beginner

Hi, 

    I have a question. Why on earth does a L2 switch i.e Cisco 2950 has the option to add a loopback interface on it? Is there any logic behind it?  it cannot do routing or anything like that then why is the option even there?

If there is any use of it please enlighten me

 

Please elaborate

1 Accepted Solution

Accepted Solutions

Joseph W. Doherty
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

For a true L2 only switch, a loopback isn't very useful.  For such devices, one possible reason Cisco might have it is the L2 switch might share code with L3 switches, and the feature is operational on the L2 switch.

Another possible reason might be Cisco has future enhancements in mind.  For example, 2960 switches used to be pure L2, but in later models and IOS versions they added basic static routing.

View solution in original post

5 Replies 5

InayathUlla Sharieff
Cisco Employee
Cisco Employee

So that you can use it for management if you want. I believe you can do a sort of static routing on layer 2 switch.

HTH

No sir we cannot do any type of static routing on a L2 only switch like a 2950 because it has no routing capability 

  cisco was never good about taking out commands that the device doesn't even support.  I had a 4500 with lanbase software and I set it up in a lab once and had full BGP running it , so sometimes they just didn't bother to take stuff out even though it's not supported on a given product.

Joseph W. Doherty
Hall of Fame Master Hall of Fame Master
Hall of Fame Master

Disclaimer

The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.

Liability Disclaimer

In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.

Posting

For a true L2 only switch, a loopback isn't very useful.  For such devices, one possible reason Cisco might have it is the L2 switch might share code with L3 switches, and the feature is operational on the L2 switch.

Another possible reason might be Cisco has future enhancements in mind.  For example, 2960 switches used to be pure L2, but in later models and IOS versions they added basic static routing.

That looks the most reasonable answer because i don't get it why do you even need a LOOPBACK interface when you cant use it in any way ! ( Atleast I cant think of any way to use it ) and yes now the 2960 latest switches are more feature enabled which includes basic routing  

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers