sessions locking using jumbo frames
With Mellanox 10G NICs and the MTUs set from 1600 to 9000 we have tcp sessions hanging. Executing ls during an sftp session just hangs. The same thing happens for an ssh session, if execute ls I might get few item in the directory but then the session hangs. Like wise for FTP. The Fujitsu switch is configured by default to handle jumbo frames. At 1500 MTU everything works fine.
We are running the 188.8.131.52 kernel with CentOS 5.2 and the Mellanox driver.
Why are these sessions dying?