we just brought CRS312-4C+8XG mainly for test purpose to see if it so good as it appears from reviews and if we can use it as iSCSI switch. So to say, even SwOS is ok for this purpose so far (really basic packet forwarding and some stats), but I simple can not manage to change MTU to use Jumbo Frames.
So the question is: if it is possible to run Jumbo Frames on CRS312-4C+8XG in SwOS (I suspect so, at lease under ROS I can change L2 MTU to 12K+), and how to do that.
P.S. Yes ROS is an option but I’d prefer to have something fast-boot and no extra options at all as SwOS for this simple task (so less code is less problems).
I know the switch is capable to work with 10k packets, but SwOS seems to use standart (1500) MTU only, and I see no options to change it. I can change it in ROS, but prefer to use SwOS.
So basically I try to find a way to set up ports to pass say 9K or 10K packets to speed up iSCSI.
Just a wild idea: assuming for a moment that SwOS leaves the MTU as it finds it, you could boot into RouterOS, change the MTU, and boot back into SwOS.
Will try but this won’t looks like serious approach: what if I reboot switch one day (power outage) and MTU become the default one while clients will expect bigger one?
Seems like ROS is the only options, even that switch control there is somewhat mystic for me
Yes, you should definitely test a poweroff. Boot RouterOS, set the MTU, set it to boot SwOS, and powercycle it. Does it still work?: You’re golden. If not (and, to be honest, I’m betting it won’t ), well, it was worth a shot.
CRS312 device booted in SwOS by default supports jumbo frames up to 10218 bytes and you cannot change it to other values. It is the same for all CRS3xx devices booted in SwOS.
), well, it was worth a shot.