Hello, This actually started with a very slow Samba file copying problem (Win2000/WinXP Clients), which I have so far tracked down to the tcp stack of 2.6. The problem is not site or other machine specific, other systems are talking with great speed. Cables/ports have been replaced/changed. Here is the data: Linux 2.6.8-smp running Fedora Core 3(beta) # mii-tool eth0 eth0: 100 Mbit, full duplex, link ok This is a CAT 5 / 100MB Short distance [50 feet] network, no routers, simple dumb switch. Nothing is being dropped or discarded on either end. # netstat -i Kernel Interface table Iface MTU Met RX-OK RX-ERR RX-DRP RX-OVR TX-OK TX-ERR TX-DRP TX-OVR Flg eth0 1500 0 478743 0 0 0 488115 0 0 0 BMRU lo 16436 0 68058 0 0 0 68058 0 0 0 LRU However, using iperf and/or nttcp this server is extremly slow to transmit: >From the linux system (192.168.1.9 is a freebsd box [5.3], no optimization) # ./nttcp -t -D 192.168.1.9 l 8388608 3.94 0.02 17.0114 4194.5662 2048 519.15 128008.0 1 8388608 4.15 0.06 16.1664 1205.6279 4757 1145.96 85460.7 # ./nttcp -r -D 192.168.1.9 l 8388608 1.56 0.06 43.0810 1048.7235 6141 3942.26 95966.6 1 8388608 1.56 0.05 43.1160 1477.1277 2048 1315.80 45078.4 Send: 17Mb/sec Receive: 43Mb/sec I had heard that there were a couple of tcp optimization tests that you could do, so I implemented, with almost no major improvement in speed (well 100% increse but its still pretty crappy) /sbin/ethtool -s eth0 speed 100 duplex full autoneg off /sbin/ifconfig eth0 mtu 1500 sysctl net.ipv4.ip_no_pmtu_disc=1 /sbin/sysctl -w net.core.rmem_default=65536 /sbin/sysctl -w net.core.wmem_default=65536 /sbin/sysctl -w net.core.rmem_max=8388608 /sbin/sysctl -w net.core.wmem_max=8388608 /sbin/sysctl -w net.ipv4.tcp_rmem="4096 87380 8388608" /sbin/sysctl -w net.ipv4.tcp_wmem="4096 65536 8388608" Any ideas would be greatly appreciated. Aram -- ----- Aram Mirzadeh - : send the line "unsubscribe linux-net" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
