Linux Distributed Switch Architecture with Local Option82 ISC DHCP server/DHCP relay

Simon Hobson dhcp1 at
Tue Nov 10 16:10:18 UTC 2020

Well, as they say, every day is a learning day. I'd not come across Distributed Switch Architecture (DSA) before - now I've read up on it, interesting.

As a refinement to the monitoring suggestion I made earlier, there's scope for switching ports between modes.

So when a port becomes inactive, switch it from packet switching within the bridge to forwarding packets direct to the processor. This will mean that when something is plugged in, the Linux network stack will be able to see the association between MAC address and port. Once that's been collected, the port can be switched back to using the in-chip switch and (potentially) offload from the processor.

I say potentially because the actual traffic flows haven't really been described by the OP. If the application basically takes streams from cameras, pipes them through the host processor and stores them on local storage - then it makes little difference.
But if there are streams between devices, using the in-chip switch would offload the handling of this from the host CPU.

As an alternative, there's scope for switching an inactive port to a different VLAN to make it appear on a different Linux network port. Then when the MAC address has been captured, change the port back to the normal VLAN.


More information about the dhcp-users mailing list