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

[Ahmed Mukhtar]

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

[InayathUlla Sharieff]

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

[Ahmed Mukhtar]

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

[glen.grant]

  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 · Accepted solution]

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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.

[Ahmed Mukhtar]

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