Loopback Addressing
Loopback
-
A logical interface
-
Always up
-
Reachable over redundant paths
-
Ideal for administrative use
-
A software interface.
- Behaves like a regular interface, but it is always always up
-
Lets say that you got a switch with 10 VLANs, if this switch is routing, it will have 10 IP's
-
You will pool the device maybe once a minute.
-
Which of these 10 IP's do we store in the network management station?
-
Because loopback is always up, we can advertise it trough dynamic routing.
-
You put an IP address on your loopback, nobody can get there but you can ping it
-
With this one IP address, we can put this one IP in every single device and advertise it through dynamic routing.
-
We can always reach our loopbacks.
Loopback Advertisement
/CAP/Network+/Visual%20Aids/Pasted%20image%2020250304163550.png)
Advertise loopback trhough dynamic routing.
Loopback address standards
- IPv4: 127.0.0.1
- IPv6: ::1