What the hell is a Loopback?

Dave Anderson · Guest

Newbie here so please be gentle. What is a loopback? I have a router with
Loopback10. With IP address of 10.1.68.70. My autoconnect is Loopback10
/xxx /yyy. But the IP address I am connecting to is 199.117.205.150. I
have also have:
ip route 199.117.205.150 255.255.255.255 192.65.82.5.

sho tcp bri shows that the router has connected to the loopback address.
But I am getting data from the 199 server. Could sombody demystify this for
me. I checked my books but I cannot find loopback in them.

accraft · Guest

Dave,
Loopbacks are virtual interfaces that can be used to make sure a router
is up for snmp or other esoteric reasons. IE in OSPF they are used as
the router ID.

Steve

Dave Anderson wrote:

Robert Chen · Guest

Loopback is also an interface that does not go down. It will always be up
even if you don't have any real interfaces with an UP/UP status. Though, I
never tried it but I assume that you can manually shut down the loopback
interface. I guess the question would be why would you want to?

"Dave Anderson" <trob@airmail.net> wrote in message
news:bi0t16$pat@library2.airnews.net...

Steve · Guest

Answer to your question robert is when you want to test your snmp
workstation and call out procedure if you area jurk of a manager. I had
one do that to me once and only once.

STeve

Robert Chen wrote: