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> "I need four computers, and they all need gigabit network interfaces... where could I find four computers to do this?" Why not loop the ports back to themsel
by unilynx 6y ago
> "I need four computers, and they all need gigabit network interfaces... where could I find four computers to do this?"
Why not loop the ports back to themselves? IIRC, 1gbit ports should autodetect when they're cross connected so it wouldn't even need special cables
- geerlingguy 6y agoWould that truly be able to test send / receive of a full (up to) gigabit of data to/from the interface? If it's loopback, it could test either sending 500 + receiving 500, or... sending 500 + receiving 500. It's like sending data through localhost, it doesn't seem to reflect a more real-world scenario (but could be especially helpful just for testing).
- nitrogen 6y agoI think maybe they meant linking Port 1 to Port 2, and Port 3 to Port 4? Also I believe gigabit ethernet can be full duplex, so you should be able to send 1000 and receive 1000 on a single interface at the same time if it's in full duplex mode.
- jlgaddis 6y agoIt's full-duplex, that's 1000 Mbps in each direction simultaneously.
- adrian_b 6y agoWhen you loop back Ethernet links in the same computer, you need to take care with the configuration, because normally the operating system will not route the Ethernet packets through the external wires but will process them like being for localhost, so you will see a very large speed without any relationship with the Ethernet speed. How to force the packets through the external wires depends on the operating system. On Linux you must use namespaces and assign the two Ethernet interfaces that are looped on each other to two distinct namespaces, then set appropriate routes.