11-16-2014 11:53 PM - edited 03-07-2019 09:32 PM
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
Solved! Go to Solution.
11-17-2014 07:50 AM
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.
11-17-2014 07:29 AM
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
11-17-2014 08:03 AM
No sir we cannot do any type of static routing on a L2 only switch like a 2950 because it has no routing capability
11-17-2014 12:35 PM
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.
11-17-2014 07:50 AM
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.
11-17-2014 08:12 AM
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
Discover and save your favorite ideas. Come back to expert answers, step-by-step guides, recent topics, and more.
New here? Get started with these tips. How to use Community New member guide