Loopback interface on router and switch

[renee-brown]

What is the take on putting on loopback interface on a router or switch. Is it secure and are there security risk in leaving them on? What access-list would apply to loopback interface that would secure any holes and denial of service attacks?

[vmiller]

some advantages of using a loopback interface is for any tunneling type protocol you always have an int that is up/up (i.e for dlsw) same for a BGP peer. Its a handy telnet target if a physical interface fails.

It also has some uses in ospf for determining router id's .

any access list that would apply to a physical interface for security would work

[renbrown]

Thanks for the info. However, it was recommended that we put loopback interfaces on devices for access when telnet or console connectivity is not available. How sound it this idea. What would your recommendations be?