nrprobenet(8)

NAME

nrprobenet - probe local net for hw/IP pairs

SYNOPSIS

update-menus [-v] [-s] [-i time] [-nodir] [-p port] [-c count] [-u time] -r IP-IP [-r IP-IP ...]

DESCRIPTION

Nrprobenet pings host on the (usually local) network, and collects data from /proc/net/arp, building tables to map ethernet numbers into IP adresses. Whenever the tables change, (optionally) writes a /etc/bootptab file to reflect the changes, and (optionally) creates tftpboot directories for new hosts found.

It can also log changes that normally shouldn't happen to syslog (i.e., an ethernet card that changes IP number, or a IP number that suddenly uses a different ethernet card).

OPTIONS

-v

Verbose output. Shows whatever host it's pinging, or not pinging, and for what reason.

-r x.x.x.x-y.y.y.y

Ping sequentially IP numbers x.x.x.x through y.y.y.y (the -r option may be given any non-zero number of times)

-u time

If time is non-zero, nrprobenet will write the /etc/bootptab file every time seconds (if anything changed in it, that is). Also, unless you give the -nodir option, it will execute mknfsroot for each new host.

-i time

Wait time seconds between each ping (default: 1)

-c count

Stop after count rounds though all the IP ranges (see -r ) (default: -1=dont't stop)

-p portnr

Use port p (default: 7=echo)

-nodir

Do not make the /tftpboot directories. If you specify the -u option, the /tftpboot/$IP directories are usually created using the mknfsroot script, unless you give the -nodir option.

-s

Log "suspicious" IP/hw changes to syslog (i.e. an ethernet card that suddenly changes IP number, or a IP number that uses a different ethernet card)

NEEDED

An nslookup that accepts one parameter (the hostname/IPnumber to lookup). The debian bind package does contain such a nslookup script.

USAGE

Usually, when you install the nfsroot package, everything is setup correctly, except for the "probenet=0" line in /etc/init.d/nrprobenet. Change that to "probenet=1" and you're set (start the programme with "/etc/init.d/nrprobenet start"). Before you do that, however, you should make sure there is enough diskspace on the directory that /tftpboot lives on (about 3--10M). If there isn't, it's usually the easiest to create a symlink from /tftpboot to /mnt/bigdisk/tftpboot. And, you may want to check whether the default network range is OK (type "source /etc/nfsroot/def; echo $IPRANGE" to find out)

FILES

/etc/nfsroot/ignorehosts

What hosts to ignore (don't ping them). This file contains regular expressions; any hostname that matches any regular expression in this file will be ignored.

/etc/bootptab

The file to write the bootptab stuff to, only if -u option is given

/etc/nfsroot/bootptab

The /et/bootptab file is created by first copying this file, and then appending the data obtained. This way, you can specify bootpd stuff for the clients.

/var/lib/nfsroot/arplist

List of all IP/hw numbers found. This is read in on startup, and written whenever new hosts are found.

/proc/net/arp

The kernel-supplied file with recent ARP data in it.

/var/run/bootpd.pid

Whenever the /etc/bootptab data changed, nrprobenet tries to SIGHUP the bootpd, to make it re-read the config data. The pid of bootpd is taken from this file.

BUGS

Does not know what to do with hosts with more than one IP number (ip forwarding).

DISTRIBUTION

Distribution is subject to the GNU public license.

AUTHOR

Joost Witteveen <[email protected]>, <[email protected]>

SEE ALSO

mknfsroot