There are a few network parameters that can be tuned to better match the kernel to your system hardware and intended usage. The defaults are usually a good choice for 99% of the people 99% of the time, but you should be aware they do exist and can be changed. The current list of parameters can be found in the file: ./linux/net/TUNABLE Some of these are accessible via the sysctl interface, and many more are scheduled to be added in this way. For example, some parameters related to Address Resolution Protocol (ARP) are very easily viewed and altered. # cat /proc/sys/net/ipv4/arp_timeout 6000 # echo 7000 > /proc/sys/net/ipv4/arp_timeout # cat /proc/sys/net/ipv4/arp_timeout 7000 Others are already accessible via the related user space programs. For example, MAX_WINDOW has a default of 32k which is a good choice for modern hardware, but if you have a slow (8 bit) ethercard and/or a slow machine, then this will be far too big for the card to keep up with fast Tx'ing machines on the same net, resulting in overruns and receive errors. A value of about 4k would be more appropriate, which can be set via: # route add -net 192.168.3.0 window 4096 The remainder of these can only be presently changed by altering a #define in the related header file. This means an edit and recompile cycle. Paul Gortmaker 06/96