Loopback address as management address

[vemulabhanu]

Hi

Can I create loopback interfaces on all my layer-3 capable switches and use this address to manage all my switches instead of using vlan 1 as management vlan.what exactly i mean is

I have a 7200 router and ten 3750 switches connected to it. So can i create loop back on all my switches and 7200 and use this address to manage all the switches.

Is this possible. If so is there any disadvantage in doing so. Thanks for your help.

[gpulos]

YES,

this is possible. of course all loopback addresses must be unique.

no real disadvantages but a very good advantage is that if an interface goes down that you previously used for access, then your access would be lost.

if you have another route to that device in that case, the loopback will always respond as it is always UP.

it's a good practice to use loopbacks in a 'management' vlan. (best practice would not use vlan1 though; vlan 2 for example would be good for the management vlan)

[vemulabhanu]

Hi gpulos

Thanks for your reply and i have two questions in ur reply

1. What does all loopback addresses must be unique means

2. Why using vlan 1 as mamagement address is not best practice and vlan2 for example is good.

[jackyoung]

1) It means all loopback address in each device should be different. loopback interface just like a logical interface in a device.

2) VLAN 1 is default and built-in VLAN in a switch, we normally will create another VLAN for the management purpose only. You can assign the management VLAN to a port then this port will only be the management segment connection or include the management VLAN in the trunk to other devices.

In real situation, many providers use loopback address for the management and routing ID due to this interface never down. And you can assign separated subnet for the management segment w/o require to use production/data network subnet.

Hope this helps.