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Diffstat (limited to 'extensions/libxt_osf.man')
| -rw-r--r-- | extensions/libxt_osf.man | 45 |
1 files changed, 45 insertions, 0 deletions
diff --git a/extensions/libxt_osf.man b/extensions/libxt_osf.man new file mode 100644 index 0000000..f3a85fb --- /dev/null +++ b/extensions/libxt_osf.man @@ -0,0 +1,45 @@ +The osf module does passive operating system fingerprinting. This modules +compares some data (Window Size, MSS, options and their order, TTL, DF, +and others) from packets with the SYN bit set. +.TP +[\fB!\fP] \fB\-\-genre\fP \fIstring\fP +Match an operating system genre by using a passive fingerprinting. +.TP +\fB\-\-ttl\fP \fIlevel\fP +Do additional TTL checks on the packet to determine the operating system. +\fIlevel\fP can be one of the following values: +.IP \(bu 4 +0 - True IP address and fingerprint TTL comparison. This generally works for +LANs. +.IP \(bu 4 +1 - Check if the IP header's TTL is less than the fingerprint one. Works for +globally-routable addresses. +.IP \(bu 4 +2 - Do not compare the TTL at all. +.TP +\fB\-\-log\fP \fIlevel\fP +Log determined genres into dmesg even if they do not match the desired one. +\fIlevel\fP can be one of the following values: +.IP \(bu 4 +0 - Log all matched or unknown signatures +.IP \(bu 4 +1 - Log only the first one +.IP \(bu 4 +2 - Log all known matched signatures +.PP +You may find something like this in syslog: +.PP +Windows [2000:SP3:Windows XP Pro SP1, 2000 SP3]: 11.22.33.55:4024 -> +11.22.33.44:139 hops=3 Linux [2.5-2.6:] : 1.2.3.4:42624 -> 1.2.3.5:22 hops=4 +.PP +OS fingerprints are loadable using the \fBnfnl_osf\fP program. To load +fingerprints from a file, use: +.PP +\fBnfnl_osf -f /usr/share/xtables/pf.os\fP +.PP +To remove them again, +.PP +\fBnfnl_osf -f /usr/share/xtables/pf.os -d\fP +.PP +The fingerprint database can be downlaoded from +http://www.openbsd.org/cgi-bin/cvsweb/src/etc/pf.os . |