> I'm seeing a > problem where the kernel attempts to send packets with a MSS > larger than the one negotiated when the TCP connection is > established. Even after ICMP "can't fragment" messages > arrive, the kernel still attempts to increase the MSS rather > aggressively. The end result is extremely poor throughput > when sending to a network with a smaller MTU.
I've tracked this problem to the TSO feature in the bnx2 driver. Turning off TSO with "ethtool -K eth1 tso off" seems to work around the problem. It appears that the bnx2 device is not using the correct mss when performing segmentation offload. -Brian "This email message and any attachments are confidential information of Starent Networks, Corp. The information transmitted may not be used to create or change any contractual obligations of Starent Networks, Corp. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon this e-mail and its attachments by persons or entities other than the intended recipient is prohibited. If you are not the intended recipient, please notify the sender immediately -- by replying to this message or by sending an email to [EMAIL PROTECTED] -- and destroy all copies of this message and any attachments without reading or disclosing their contents. Thank you." - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
