]>
Commit | Line | Data |
---|---|---|
aba5acdf SH |
1 | <!doctype linuxdoc system> |
2 | ||
3 | <article> | |
4 | ||
5 | <title>RTACCT Utility | |
6 | <author>Robert Olsson | |
7 | <date>some_negative_number, 20 Dec 2001 | |
8 | ||
9 | <p> | |
10 | Here is some code for monitoring the route cache. For systems handling high | |
11 | network load, servers, routers, firewalls etc the route cache and its garbage | |
12 | collection is crucial. Linux has a solid implementation. | |
13 | ||
14 | <p> | |
15 | The kernel patch (not required since linux-2.4.7) adds statistics counters | |
16 | from route cache process into | |
17 | /proc/net/rt_cache_stat. A companion user mode program presents the statistics | |
18 | in a vmstat or iostat manner. The ratio between cache hits and misses gives | |
19 | the flow length. | |
20 | ||
21 | <p> | |
22 | Hopefully it can help understanding performance and DoS and other related | |
23 | issues. | |
24 | ||
25 | <p> An URL where newer versions of this utility can be (probably) found | |
26 | is ftp://robur.slu.se/pub/Linux/net-development/rt_cache_stat/ | |
27 | ||
28 | ||
29 | <p><bf/Description/ | |
30 | ||
31 | <p>The format of the command is: | |
32 | ||
33 | <tscreen><verb> | |
34 | rtstat [ OPTIONS ] | |
35 | </verb></tscreen> | |
36 | ||
37 | <p> <tt/OPTIONS/ are: | |
38 | ||
39 | <itemize> | |
40 | ||
41 | <item><tt/-h/, <tt/-help/ - show help page and version of the utility. | |
42 | ||
43 | <item><tt/-i INTERVAL/ - interval between snapshots, default value is | |
44 | 2 seconds. | |
45 | ||
46 | <item><tt/-s NUMBER/ - whether to print header line. 0 inhibits header line, | |
47 | 1 prescribes to print it once and 2 (this is default setting) forces header | |
48 | line each 20 lines. | |
49 | ||
50 | </itemize> | |
51 | ||
52 | </article> |