Commit | Line | Data |
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1da177e4 LT |
1 | |
2 | There are a few network parameters that can be tuned to better match | |
3 | the kernel to your system hardware and intended usage. The defaults | |
4 | are usually a good choice for 99% of the people 99% of the time, but | |
5 | you should be aware they do exist and can be changed. | |
6 | ||
7 | The current list of parameters can be found in the files: | |
8 | ||
9 | linux/net/TUNABLE | |
10 | Documentation/networking/ip-sysctl.txt | |
11 | ||
12 | Some of these are accessible via the sysctl interface, and many more are | |
13 | scheduled to be added in this way. For example, some parameters related | |
14 | to Address Resolution Protocol (ARP) are very easily viewed and altered. | |
15 | ||
16 | # cat /proc/sys/net/ipv4/arp_timeout | |
17 | 6000 | |
18 | # echo 7000 > /proc/sys/net/ipv4/arp_timeout | |
19 | # cat /proc/sys/net/ipv4/arp_timeout | |
20 | 7000 | |
21 | ||
22 | Others are already accessible via the related user space programs. | |
23 | For example, MAX_WINDOW has a default of 32 k which is a good choice for | |
24 | modern hardware, but if you have a slow (8 bit) Ethernet card and/or a slow | |
25 | machine, then this will be far too big for the card to keep up with fast | |
26 | machines transmitting on the same net, resulting in overruns and receive errors. | |
27 | A value of about 4 k would be more appropriate, which can be set via: | |
28 | ||
29 | # route add -net 192.168.3.0 window 4096 | |
30 | ||
31 | The remainder of these can only be presently changed by altering a #define | |
32 | in the related header file. This means an edit and recompile cycle. | |
33 | ||
34 | Paul Gortmaker 06/96 |