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|
.TH NETSELECT 1 "March 14, 2004" "DEBIAN" \" -*- nroff -*-
.\" Please adjust this date whenever revising the manpage.
.SH NAME
netselect \- choose the fastest server automatically
.SH SYNOPSIS
.B netselect
.RB [ \|\-v\| | \|\-vv\| | \|\-vvv\| | \|\-vvvv\| ]
.\".RB [ \|\-vv\| ]
.RB [ \|\-m
.IR HOPS ]
.RB [ \|\-s
.IR SERVERS\| ]
.RB [ \|\-t
.IR PACKETS\| ]
.IR host \ ...
.SH DESCRIPTION
.B netselect
determines several facts about all of the hosts given on the command
line, much faster than you would if you manually tried to use
.B ping
and
.BR traceroute .
For each
.IR host ,
.B netselect
figures out the approximate
.B ping
time (though not as accurately as
.B ping
does), the number of network "hops" to
reach the target, and the percentage of
.B ping
requests that got through successfully. Then
.B netselect
calculates the "score" of each operational
.I host
based on these values. A lower score is better, in the end it prints
one line showing the server with the best score.
.SH EXAMPLES
.nf
\fB#\fR netselect \-vv ftp.fceia.unr.edu.ar ftp.kulnet.kuleuven.ac.be \\
ftp.cdrom.com ftp.debian.org ftp.de.debian.org
.fi
This is the output:
.nf
ftp.fceia.unr.edu.ar 2792 ms 23 hops 100% ok ( 1/ 1) [ 9213]
ftp.kulnet.kuleuven.ac.be 9999 ms 30 hops 0% ok
ftp.cdrom.com 94 ms 8 hops 100% ok (10/10) [ 169]
ftp.debian.org 46 ms 15 hops 100% ok (10/10) [ 115]
ftp.de.debian.org 9999 ms 30 hops 0% ok
115 ftp.debian.org
.fi
The value in brackets is the "score" of each operational host based on these
values. A lower score is better. The last line shows the server with the
best score. If we had not used '\-vv' on the command line, only this last
line would have been printed.
Note that for ftp.kulnet.kuleuven.ac.be and ftp.de.debian.org in this case,
nothing got through at all. That indicates that either the host doesn't
exist, or it is down.
.SH OPTIONS
.TP
.B \-v
Verbose mode. Displays nameserver resolution messages to stderr. You
probably want this so that you don't get bored waiting for a hundred
name resolutions to finish.
.TP
.B \-vv
Very verbose mode. Displays nameserver resolution and statistics (not
just scores) to STDERR and STDOUT.
.TP
.B \-vvv
Very very verbose mode. Everything \-vv prints, plus it print every
packet received as it happens. Good for debugging or trying to figure
out how it works.
.TP
.B \-vvvv
Very very very verbose mode. Everything \-vvv prints, plus a trace of
all packets sent.
.TP
.BI \-m\ HOPS
Maximum TTL (time to live). Don't accept hosts that are further than
.I HOPS
away.
.TP
.BI \-s\ SERVERS
Print this many "top-scoring"
.I SERVERS
at the end of the list. If
.I SERVERS
is 0, then this disables printing of high scores.
.TP
.BI \-t\ PACKETS
Make sure at least 50% of the hosts get tested with this many
.IR PACKETS .
The more packets you use, the more accurate are the results... and the
longer it takes to run. The default is 10, which is usually okay.
.SH SEE ALSO
.BR ping (8),
.BR traceroute (8),
.BR netselect-apt (1).
.SH AUTHOR
Avery Pennarun <apenwarr@nit.ca>
|
