ASTRACEROUTE(8) netsniff-ng toolkit ASTRACEROUTE(8)NAME
astraceroute - autonomous system trace route utility
SYNOPSIS
astraceroute [options]
DESCRIPTION
astraceroute is a small utility to retrieve path information in a
traceroute like way, but with additional geographical location informa‐
tion. It tracks the route of a packet from the local host to the remote
host by successively increasing the IP's TTL field, starting from 1, in
the hope that each intermediate node will send an ICMP TIME_EXCEEDED
notification back to the local host when the TTL value is decremented
to 0.
astraceroute supports IPv4 and IPv6 queries and will display country
and city information, if available, the AS number the hop belongs to,
and its ISP name. astraceroute also displays timing information and
reverse DNS data.
Due to astraceroute's configurability, it is also possible to gather
some more useful information about the hop regarding what it does and
does not allow to pass through. This is done by using clear text
strings for probing DPIs or keywords. This tool might be a good start
for further in-depth analysis of such systems.
OPTIONS-H <host>, --host <host>
Hostname or IPv4 or IPv6 address of the remote host where the AS route
should be traced to. In the case of an IPv6 address or host, option
''-6'' must be used. IPv4 is the default.
-p <port>, --port <port>
TCP port for the remote host to use. If not specified, the default port
used is 80.
-i <device>, -d <device>, --dev <device>
Networking device to start the trace route from, e.g. eth0, wlan0.
-f <ttl>, --init-ttl <ttl>
Initial TTL value to be used. This option might be useful if you are
not interested in the first n hops, but only the following ones. The
default initial TTL value is 1.
-m <ttl>, --max-ttl <ttl>
Maximum TTL value to be used. If not otherwise specified, the maximum
TTL value is 30. Thus, after this has been reached astraceroute exits.
-q <num>, --num-probes <num>
Specifies the number of queries to be done on a particular hop. The
default is 2 query requests.
-x <sec>, --timeout <sec>
Tells astraceroute the probe response timeout in seconds, in other
words the maximum time astraceroute must wait for an ICMP response from
the current hop. The default is 3 seconds.
-X <string>, --payload <string>
Places an ASCII cleartext string into the packet payload. Cleartext
that contains whitespace must be put into quotes (e.g.: "censor me").
-l <len>, --totlen <len>
Specifies the total length of the packet. Payload that does not have a
cleartext string in it is padded with random garbage.
-4, --ipv4
Use IPv4 only requests. This is the default.
-6, --ipv6
Use IPv6 only requests. This must be used when passing an IPv6 host as
an argument.
-n, --numeric
Tells astraceroute to not perform reverse DNS lookup for hop replies.
The reverse option is ''-N''.
-u, --update
The built-in geo-database update mechanism will be invoked to get Max‐
mind's latest version. To configure search locations for databases, the
file /etc/netsniff-ng/geoip.conf contains possible addresses. Thus, to
save bandwidth or for mirroring Maxmind's databases (to bypass their
traffic limit policy), different hosts or IP addresses can be placed
into geoip.conf, separated by a newline.
-L, --latitude
Also show latitude and longitude of hops.
-N, --dns
Tells astraceroute to perform reverse DNS lookup for hop replies. The
reverse option is ''-n''.
-S, --syn
Use TCP's SYN flag for the request.
-A, --ack
Use TCP's ACK flag for the request.
-F, --fin
Use TCP's FIN flag for the request.
-P, --psh
Use TCP's PSH flag for the request.
-U, --urg
Use TCP's URG flag for the request.
-R, --rst
Use TCP's RST flag for the request.
-E, --ecn-syn
Use TCP's ECN flag for the request.
-t <tos>, --tos <tos>
Explicitly specify IP's TOS.
-G, --nofrag
Set IP's no fragmentation flag.
-Z, --show-packet
Show and dissect the returned packet.
-v, --version
Show version information and exit.
-h, --help
Show user help and exit.
USAGE EXAMPLE
astraceroute -i eth0 -N -S -H netsniff-ng.org
This sends out a TCP SYN probe via the ''eth0'' networking device to
the remote IPv4 host netsniff-ng.org. This request is most likely to
pass. Also, tell astraceroute to perform reverse DNS lookups for each
hop.
astraceroute -6 -i eth0 -S -E -N -H www.6bone.net
In this example, a TCP SYN/ECN probe for the IPv6 host www.6bone.net is
being performed. Also in this case, the ''eth0'' device is being used
as well as a reverse DNS lookup for each hop.
astraceroute -i eth0 -N -F -H netsniff-ng.org
Here, we send out a TCP FIN probe to the remote host netsniff-ng.org.
Again, on each hop a reverse DNS lookup is being done and the queries
are transmitted from ''eth0''. IPv4 is used.
astraceroute -i eth0 -N -FPU -H netsniff-ng.org
As in most other examples, we perform a trace route to IPv4 host net‐
sniff-ng.org and do a TCP Xmas probe this time.
astraceroute -i eth0 -N -H netsniff-ng.org -X censor-me -Z
In this example, we have a Null probe to the remote host netsniff-
ng.org, port 80 (default) and this time, we append the cleartext string
"censor-me" into the packet payload to test if a firewall or DPI will
let this string pass. Such a trace could be done once without, and once
with, a blacklisted string to gather possible information about censor‐
ship.
NOTE
If a TCP-based probe fails after a number of retries, astraceroute will
automatically fall back to ICMP-based probes to pass through firewalls
and routers used in load balancing for example.
To gather more information about astraceroute's displayed AS numbers,
see e.g.: http://bgp.he.net/AS<number>.
BUGS
The geographical locations are estimated with the help of Maxmind's
GeoIP database and can differ from the real physical location. To
decrease the possible errors, update the database regularly using
astraceroute's --update option.
At some point in time, we need a similar approach to gather more reli‐
able path information such as in the paris-traceroute tool.
Due to the generic nature of astraceroute, it currently has a built-in
mechanism to stop the trace after a fixed number of hops, since the
configurable TCP flags can have anything included. It is possible to
decrease this number of course. In the future, if a SYN probe is sent
out, there should be a listener so that we can stop the trace if we
detect a handshake in progress.
LEGAL
astraceroute is licensed under the GNU GPL version 2.0.
HISTORY
astraceroute was originally written for the netsniff-ng toolkit by
Daniel Borkmann. It is currently maintained by Tobias Klauser
<tklauser@distanz.ch> and Daniel Borkmann <dborkma@tik.ee.ethz.ch>.
SEE ALSOnetsniff-ng(8), trafgen(8), mausezahn(8), ifpps(8), bpfc(8), flow‐
top(8), curvetun(8)AUTHOR
Manpage was written by Daniel Borkmann.
COLOPHON
This page is part of the Linux netsniff-ng toolkit project. A descrip‐
tion of the project, and information about reporting bugs, can be found
at http://netsniff-ng.org/.
Linux 03 March 2013 ASTRACEROUTE(8)
