Loopback address on Layer 2 switch for management?

[pramod431]

Hi,

   I got a situation that I have to configure a loopback interface on layer 2 switch for management in the routed network. Is it possible to manage a layer 2 switch by Telnet the loopback address  form a remote host which is not in the same network?

Thank you,

Pramod.

[Edwin Summers]

Yes.  Configure a default gateway on the switch so it has a gateway through which to reach other networks.

ip default-gateway

Best regards,

Ed

[pramod431]

Thanks for the reply, but the other way how the default-gateway knows about the l2 switch loopback address when it receives the IP packet with l2 switch loop back address as the destination. To where the default-gateway forwords this packet?

Thank you,

Pramod

[Edwin Summers]

The loopback interface will be the same as any other host on the network served by the (default) gateway.  So of course, the loopback interface IP address must be on the same network/subnet as the default gateway address.

[charles.r.green]

Good Morning Pramod,

     Have you ever considered using a Management VLAN to Telnet into all of your switches? Management VLANs are a lot easier to keep track of and all the traffic passes over Layer 3 links as well as any Layer 2 links, such as Trunks. Another question is, why are you using Telnet? As an Administrator for your network, you should be using SSH, even if this network is your home network. Let me know if I can help you out.  I have to same issue a month ago.

Respectfully,

Charles

[glen.grant]

  My question is why do you have to use a loopback address to manage the switch?  Loopbacks are generally used on routers and L3 switches as  a always active interface for routing protocols.  I'm not sure you could use a loopback on a L2 switch , at least in a trunked environment because it is not associated with a particular vlan .  Possibly it might work if the network that the loopback is associated with is in the native vlan . This is something that you could play with in a lab environment.

[Edwin Summers]

Oi!  Absolutely, Glen.  Must be Monday all over again...I had SVI on the brain and loopback on the tongue.

[pramod431]

Please find the below image, this is exactly what my situation is.

1. I AM USING OSPF AS ROUTING PROTOCOL

2. I WAS ASKED TO ASSIGN LOOPBACK ADDRESS FOR EACH SWITCH FOR MANAGEMENT.

3. I WAS ABLE TO ASSIGN LOOPBACK FOR L3 SWITCH AND REDISTIBUTE INTO OSPF. BUT I DON'T KNOW HOW TO MAKE COMMUNICATION WORK BETWEEN PC2 AND L2SW1 LOOPBACK OR L2SW2 LOOPBACK

L2-- LAYER 2 AND L3-- LAYER 3

Thank you,

Pramod.

[mahmoodmkl]

Hi
If all of u r network is L3 then it makes sense to have loopback interfaces on u r switches,if it is L2 then u will not be utilize the purpose of loopbacks

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