Noun
loopback (countable and uncountable, plural loopbacks)
English Wikipedia has an article on:loopbackWikipedia
The routing of a signal, data stream, etc. from its origin back to the origin, primarily as a means of testing the transmission or transportation infrastructure.
A router with the NAT loopback feature detects that 203.0.113.1 is the address of its WAN interface, and treats the packet as if coming from that interface. Source: Internet
And of course lo0 is the loopback adapter. Source: Internet
Alta and Telluride are obviously not directly connected, and the loopback addresses do not belong to the same subnet, yet just as obviously in Example 2-23 the EBGP session between their loopback interfaces works. Source: Internet
LXD (localhost) does not officially support attaching loopback devices for storage out of the box. Source: Internet
Simple reachability is configured with OSPF between Telluride and Copper, a static route at Copper for Alta’s loopback address, and a static default route pointing to Copper at Alta. Most important, notice that there is no BGP running at Copper. Source: Internet
The IBGP sessions are all up (because of OSPF advertising the loopback addresses). Source: Internet