Hello together, we upgraded from kernel 2.6.23.16 to 2.6.24.7 and are now seeing stalling (smtp) TCP connections on two boxes. We still have the old kernel on a "rescue" partition. If I boot it up, the connections work immediately. The connection work fine if the transmitted data is smaller than ~220kb, so you still can send small messages. I've sent a tcpdump to Patrick in private as it contained sensitive information. The picture is similar to Sven's issue reported backed in march: Some ACK packets are missing (as if the remote side never sent them). I downgraded the box to 2.6.24 to make sure it was not caused by any -stable patch. Same thing. Did any default TCP settings change from 2.6.23.16 to 2.6.24? I also tried to disable path MTU discovery, TCP window scaling and lowered the MTU of the ppp0 interface to 1400 (DSL connection). This had no visible effect. @Sven: Were you able to test 2.6.24.2? Patrick suggested to enable nf_conntrack_log_invalid. I enabled it via "echo 255 > /proc/sys/net/netfilter/nf_conntrack_log_invalid" but that change didn't print anything to syslog. Any ideas? Have a nice weekend, Thomas -- To unsubscribe from this list: send the line "unsubscribe netfilter-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
