[Beowulf] SMC 8524T jumbo frame problems

Sean Dilda agrajag at dragaera.net
Tue Sep 28 17:51:00 PDT 2004

On Tue, 2004-09-28 at 19:24, Chris Samuel wrote:
> Hi folks,
> We've recently picked up a number of SMC 8524T 24-port gig switches to build a 
> separate pan-cluster network for filesystem I/O because all the blurb we can 
> find says that they support jumbo frames.
> However, although our IBM x335 nodes (BCM5703 adapters and bcm5700 drivers) 
> can happily talk to each other with an MTU of 9000 when connected via a 
> crossover cable, once we plug them into the switch any MTU in excess of 1500 
> results in no communication according to tracepath. :-(
> Anyone here got any experience with these and any pointers to what we might be 
> missing ?

I have a similar switch (sold through Dell, but basically the same
switch).  In order to use jumbo frames, you have to enable it on the
switch.  This can be done through the web interface (not sure the exact
links), or through the command line interface.

To do it through the command line interface, you first need to telnet or
ssh the switch and login as an admin account.  (by default user: admin
password: admin)  Once you're logged in, you'll want to type 'config' to
get to config mode, then type 'jumbo frame'.  It should look something
like this:

chg-sw1-0(config)#jumbo frame

You probably also want to save the settings in case the switch reboots. 
You do that as follows:

chg-sw1-0#copy running-config startup-config
Startup configuration file name [startup]: startup

Hope that helps,


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