Amer Networks E5Web GUI - Manual (Page 179)

Name The name of the interface for display and reference in cOS Core.
Loop to This is the name of the other loopback interface in the pair. The other interface
will have this loopback interface as its Loop to parameter.
For a pair, the Loop to parameter must be left blank when the first interface is
created and then filled in later after its partner is created.
IP Address The IP address assigned to the loopback interface. This is the address that can
be "Pinged" and can be used as the source address for dynamically translated
connections.
Network The network assigned to the loopback interface and to which the IP Address
above belongs. This does not have to be the same network as the other
loopback interface in the pair.
One of two options can then be selected depending on how the loopback interface is to be used
with routing tables:
• Make the interface a member of all routing tables
Traffic arriving on this loopback interface will be routed according to the main routing table,
by default.
With this option (which is the default), routes for this interface's IP will be inserted
automatically into all routing tables.
• Make interface a member of a specific routing table
Specifies the routing table to insert the interface IP route into. It also means that the specified
routing table will be used for all routing lookups for this interface unless overridden by a
routing rule.
With this option, a single route for this interface's IP will be inserted automatically the
specified routing table.
Note: Only the interface IP route is added automatically
Although routes are inserted automatically into routing tables when loopback
interfaces are created these are only for the IP specified for the interface. Extra routes will
most likely have to be added manually, such as the all-nets route in the example below.
Loopback Interface IP Addresses
Loopback interfaces are configured with IP addresses, just as with any other interface type.
However, these IP addresses can be fictitious and the addresses for the pair do not need to be on
the same network although they should be different.
The IP address assigned to a loopback interface is used as the source address for any dynamically
translated connections that are routed over the interface.
If the interface is not used for this purposes then it is more consistent to set the address to one in
the range of the standard loopback IP addresses which is 127.0.0.0 to 127.255.255.255.
A Summary of Loopback Interface Setup
Chapter 3: Fundamentals
179