On Thu, 06 Dec 2018 16:26:55 GMT, Tim wrote:

mechanic wrote in news:e2qt8nor9swp
:

On Wed, 05 Dec 2018 14:40:58 -0500, nospam wrote:

in some cases, a router *does* directly connect to the internet.

By strict definition, a router receives a digital packet from one port, and
uses that packet's destination address info to select which other port to
sent it out of, thus 'routing' it to its destination.

Where port = router interface.

In addition, the incoming interface and the outgoing interface on the
router can be the same interface, although for performance reasons that
won't usually be the case. Also, routers don't forward traffic
unchanged. Every packet gets its source MAC rewritten to that of the
router's outgoing interface, and the destination MAC gets rewritten to
that of the next hop gateway. Source and destination IP addresses are
left unchanged, of course.

Interestingly, most routers have no idea how to get a packet to its
destination. What they do know, however, is how to get the packet one
step (hop) closer, so they punt it off in that direction. Every router
gets to decide the most appropriate next hop, and that decision may
change from one second to the next. Thus, two packets going from A to B
may not follow the same path.