I repeated the test with tso off in the NIC. Process as follows: 1. Stop Exim, remove fastopen exclusion in transport conf. 2. ethtool -K eth0 tso off; ethtool -K eth0 tx off 3. Restart exim, retest.
Still experiencing timeouts in a similar fashion much as before - tshark summary: https://www.chromosphere.co.uk/wp-content/blogs.dir/1/files/2022/08/tfo_nic.txt Of note, here's the output from ethtool --show-offload when I ran the test: # ethtool --show-offload eth0 Features for eth0: rx-checksumming: on [fixed] tx-checksumming: off tx-checksum-ipv4: off [fixed] tx-checksum-ip-generic: off tx-checksum-ipv6: off [fixed] tx-checksum-fcoe-crc: off [fixed] tx-checksum-sctp: off [fixed] scatter-gather: on tx-scatter-gather: on tx-scatter-gather-fraglist: off [fixed] tcp-segmentation-offload: off tx-tcp-segmentation: off tx-tcp-ecn-segmentation: off tx-tcp-mangleid-segmentation: off tx-tcp6-segmentation: off generic-segmentation-offload: on generic-receive-offload: on large-receive-offload: off [fixed] rx-vlan-offload: off [fixed] tx-vlan-offload: off [fixed] ntuple-filters: off [fixed] receive-hashing: off [fixed] highdma: on [fixed] rx-vlan-filter: on [fixed] vlan-challenged: off [fixed] tx-lockless: off [fixed] netns-local: off [fixed] tx-gso-robust: on [fixed] tx-fcoe-segmentation: off [fixed] tx-gre-segmentation: off [fixed] tx-gre-csum-segmentation: off [fixed] tx-ipxip4-segmentation: off [fixed] tx-ipxip6-segmentation: off [fixed] tx-udp_tnl-segmentation: off [fixed] tx-udp_tnl-csum-segmentation: off [fixed] tx-gso-partial: off [fixed] tx-tunnel-remcsum-segmentation: off [fixed] tx-sctp-segmentation: off [fixed] tx-esp-segmentation: off [fixed] tx-udp-segmentation: off [fixed] tx-gso-list: off [fixed] fcoe-mtu: off [fixed] tx-nocache-copy: off loopback: off [fixed] rx-fcs: off [fixed] rx-all: off [fixed] tx-vlan-stag-hw-insert: off [fixed] rx-vlan-stag-hw-parse: off [fixed] rx-vlan-stag-filter: off [fixed] l2-fwd-offload: off [fixed] hw-tc-offload: off [fixed] esp-hw-offload: off [fixed] esp-tx-csum-hw-offload: off [fixed] rx-udp_tunnel-port-offload: off [fixed] tls-hw-tx-offload: off [fixed] tls-hw-rx-offload: off [fixed] rx-gro-hw: on [fixed] tls-hw-record: off [fixed] rx-gro-list: off macsec-hw-offload: off [fixed] On Fri, 12 Aug 2022 at 07:09, Viktor Dukhovni via Exim-users < exim-users@exim.org> wrote: > On Fri, Aug 12, 2022 at 06:30:21AM +0100, Andrew C Aitchison via > Exim-users wrote: > > > > It looks *strongly* like an interoperability problem between the Linux > > > kernel TCP implementation and the Google TCP/TLS termination > front-ends, > > > unless all the Exim users who lately somewhat regularly show up to > > > report this issue are behind some as yet unidentified set of > > > middle-boxes that break TCP state. > > > > > > It would perhaps be useful to also see any reports of success sending > > > sufficiently large messages to Gmail from the reported Exim builds and > > > Linux versions. If some users are not seeing any issues, then it would > > > be good to know how their situation is differs. > > > > Might be good to know who is using openssl and who is using gnu-tls, > > so that we can rule in or out the tls implementation. > > Surely irrelevant, this is a *TCP-layer* problem. If not in the Linux > kernel, perhaps in the TCP offload in the network card. > > -- > Viktor. > > -- > ## List details at https://lists.exim.org/mailman/listinfo/exim-users > ## Exim details at http://www.exim.org/ > ## Please use the Wiki with this list - http://wiki.exim.org/ > -- ## List details at https://lists.exim.org/mailman/listinfo/exim-users ## Exim details at http://www.exim.org/ ## Please use the Wiki with this list - http://wiki.exim.org/
