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Old 28th January 2015
ocicat ocicat is offline
Join Date: Apr 2008
Posts: 3,298

Originally Posted by PingPing View Post
...a categorical answer would be appreciated.
At boot-time, a switch will know nothing about what MAC addresses are attached, so the initial traffic is broadcasted to all active switch ports. As traffic commences, the source & destination addresses within each packet encountered will be looked at, & placed into the switch's ARP table keyed by the switch port attachment. The presence of gigabyte & slower ports should not make any difference.

If you interested in empirically testing, enable logging through the router's packet filter. If the end points are on the same network segment, packets do not need to go through the router at all. No logging will be seen.

However, packets can be forced through the router if the switch supports virtual networks or VLAN's. The endpoints would need to reside on different VLAN's, & the router would have to be configured to send packets from one VLAN to the next. In this scenario, the packets would have to traverse the router to reach their destination. This topology is frequently called a "router on a stick".

Most consumer switches targeting the home market do not support VLAN's.

Last edited by ocicat; 28th January 2015 at 07:46 PM. Reason: Insert missing participle
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