On Fri, 26 Sept 2025 at 23:48, CAREY SCHUG via Talk <talk@lists.gtalug.org> wrote:
4. setting up a managed switch so I can make a promiscuous port is more than I'd like to take on.
Why are you so intimidated about using a managed switch? "Out of the box" a managed switch will behave the same as an unmanaged one. Logging in to the web interface of the switch and only enabling what you call promiscuous mode (but is more often called monitoring or mirroring) on a port should be relatively easy. A 5 port managed switch won't be very expensive. E.g. https://www.amazon.ca/NETGEAR-Ethernet-Manageable-Affordable-Connectivity/dp... For that Netgear GS305E switch, it's called port mirroring and instructions on how to enable it can be found on page 68 of the User Manual https://www.downloads.netgear.com/files/GDC/GS105EV2/WebManagedSwitches_UM_E...
14. UNRELATED, but since AI did not know (said "no limit"), if i have switches connected to switches, what is the limit for the total number of addresses one port on the switch can know it has to forward to that port? I assume this varies between models and manufacturesrs, and hopefully exceeds 253 so a "normal" minimum would never be a problem, but if you were using 10.x, the top switch coull have to forward to millions of random addresses on each port.
Unless it has extra intelligence, a switch does its routing based on the lower layer MAC addresses, not IP addresses, so it's more of a question of how many devices (unique MAC addresses) can be handled on one port. It's usually done using a global table, i.e. MAC address to port number mapping. The table size would be at least a thousand entries, even for the most basic switch. The GS305E I mentioned above has an 8K table. -- Scott