.Dd September 25, 2001
.Dt cdpd 8
.Sh NAME
.Nm cdpd
.Nd Send CDP packets over ethernet.
.Sh SYNOPSIS
.Nm cdpd
.Op Fl d
.Op Fl i Ar interface
.Op Fl h 
.Op Fl t Ar period
.Op Fl o 
.Op Fl a 
.Sh DESCRIPTION
The 
.Nm
utiliy used to generate Cisco Discovery Protocol packets and
send them over ethernet.
.Pp
The options are as follows:
.Bl -tag -width Ds
.It Fl d 
increase debugging level and do not daemonise, as debug sent on stdout
.It Fl i Ar interface
set interface, over that packets will be sent
.It Fl h 
get help message
.It Fl t Ar period 
set the period between packets sent (60 sec by default)
.It Fl o 
sent only one packet and than exit
.It Fl a
try to add all iinterfaces with ip addresses configured
to those added with 
.Sy -i
option
.El
.Sh DIAGNOSTICS
When everything is ok, 
and 
.Nm
program is started with (default) daemon mode, it justs
daemonises with return code 0. 
In case of errors they are printed to stderr and program exists
with non-zero status. Most errors caused by the fact that
the 
.Nm
needs access to /dev/bpf*, so it must be started by root, and
Berkeley Packet Filter must be enabled in kernel (by adding 
.Sy pseudo-device bpf
into kernel configuration).
.Sh ADDITIONAL NOTE
Some people proposed option of collecting information from 
an ethernet interfaces to have some table like cisco 'show cdp nei'
command output. But, as you can retrieve this information from 
modern tcpdump program (with 
.Sy -i <interface> ether dst 01:00:0c:cc:cc:cc
flags) and this feature leads to expensive CPU usage, 
this feature will not be realized in cdpd.
.Sh BUGS
Due to libnet limitation, program can't work with more than one interface 
on Solaris. And, even in case of one interface under Solaris, this 
interface must be 'le0'. See libnet sources for description... 
.Sh SEE ALSO
.Sy http://www.cisco.com/
for information about Cisco Discovery Protocol.
.Sy http://www.tcpdump.org/
- tcpdump home page.
.Sh AUTHOR
Alexandre Snarskii, <snar@paranoia.ru>