cdpd(8)

NAME
cdpd - Send CDP packets over ethernet.

SYNOPSIS
cdpd [-d] [-i interface] [-h] [-t period] [-o] [-a]

DESCRIPTION
The cdpd utiliy used to generate Cisco Discovery Protocol packets and send them over ethernet.

The options are as follows:

-d  increase debugging level and do not daemonise, as debug sent on stdout

-i interface
    set interface, over that packets will be sent

-h  get help message

-t period
    set the period between packets sent (60 sec by default)

-o  sent only one packet and than exit

-a  try to add all iinterfaces with ip addresses configured to those added with -i option

DIAGNOSTICS
When everything is ok, and cdpd 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 cdpd needs access to /dev/bpf*, so it must be started by root, and Berkeley Packet Filter must be enabled in kernel (by adding pseudo-device bpf into kernel configuration).

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 -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.

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...

SEE ALSO
http://www.cisco.com/ for information about Cisco Discovery Protocol. http://www.tcpdump.org/ - tcpdump home page.

AUTHOR
Alexandre Snarskii, <snar@paranoia.ru>