Copyright (c) 2001 Dug Song <dugsong@monkey.org>

$Id: fragroute.8.in,v 1.5 2002/04/15 14:18:42 dugsong Exp $

fragroute - intercept, modify, and rewrite egress traffic fragroute [-f file] host fragroute intercepts, modifies, and rewrites egress traffic destined for the specified host , implementing most of the attacks described in the Secure Networks ``Insertion, Evasion, and Denial of Service: Eluding Network Intrusion Detection'' paper of January 1998.

The options are as follows:

Read ruleset from the specified file instead of @FRAGROUTE_CONF@ .

Unlike fragrouter (8), this program only affects packets originating from the local machine destined for a remote host . Do not enable IP forwarding on the local machine.

fragroute is composed of several modules which enable various configuration directives. Each directive operates on a logical packet queue handed to it by the previous rule.

# " string ..." Ruleset comment, no-op.

"delay first" | last | random " " ms Delay the delivery of the first, last, or a randomly selected packet from the queue by ms milliseconds.

"drop first" | last | random " " prob-% Drop the first, last, or a randomly selected packet from the queue with a probability of prob-% percent.

"dup first" | last | random " " prob-% Duplicate the first, last, or a randomly selected packet from the queue with a probability of prob-% percent.

echo " string ..." Echo the string argument(s) to standard output.

"ip_chaff dup" | opt | ttl Interleave IP packets in the queue with duplicate IP packets containing different payloads, either scheduled for later delivery, carrying invalid IP options, or bearing short time-to-live values.

"ip_frag " size " " [ old | new ] Fragment each packet in the queue into size -byte IP fragments, preserving the complete transport header in the first fragment. Optional fragment overlap may be specified as old " or " new , to favor newer or older data.

"ip_opt lsrr" | "ssrr " "ptr ip-addr ..." Add IP options to every packet, to enable loose or strict source routing. The route should be specified as list of IP addresses, and a bytewise pointer into them (e.g. the minimum ptr value is 4).

"ip_ttl " ttl Set the IP time-to-live value of every packet to ttl .

"ip_tos " tos Set the IP type-of-service bits for every packet to tos .

order " " random | reverse Re-order the packets in the queue randomly, or in reverse.

print Print each packet in the queue in tcpdump-style format.

tcp_chaff " " cksum | null | paws | rexmit | seq | syn | ttl Interleave TCP segments in the queue with duplicate TCP segments containing different payloads, either bearing invalid TCP checksums, null TCP control flags, older TCP timestamp options for PAWS elimination, faked retransmits scheduled for later delivery, out-of-window sequence numbers, requests to re-synchronize sequence numbers mid-stream, or short time-to-live values.

tcp_opt " " mss | wscale " size" Add TCP options to every TCP packet, to set the maximum segment size or window scaling factor.

"tcp_seg " size " " [ old | new ] Segment each TCP data segment in the queue into size -byte TCP segments. Optional segment overlap may be specified as old " or " new , to favor newer or older data.

Fragment all traffic to a Windows host into forward-overlapping 8-byte fragments (favoring older data), reorder randomly, and print to standard output:

 ip_frag 8 old
 order random
 print

Segment all TCP data to a host into forward-overlapping 4-byte segments (favoring newer data), interleave with overwriting, random chaff segments bearing older timestamp options for PAWS elimination, reorder randomly, and print to standard output:

 tcp_seg 4 new
 tcp_chaff paws
 order random
 print

@FRAGROUTE_CONF@ Default configuration ruleset

fragtest (8) Dug Song <dugsong@monkey.org> It is entirely possible to mangle your outgoing traffic so badly that no remote TCP/IP stack will accept it. K.I.S.S.