Andrew's Sprocket

This is a useful packet grabber using tcpdump.
You don’t get as many details as wireshark or ethereal but running this on a remote server is easier.

First find out what network interface you want to capture.

$ ifconfig

Then start capturing and write to a file with -w

$ tcpdump -i eth0 -w eth0-dump.log

You can then read the file with the -r switch

$ tcpdump -r eth0-dump.log

To change the system date/time in Linux create a symlink to /etc/localtime for the correct time zone.

Verify the new time with “date” then update the hardware clock with “hwclock”

$ ln -sf /usr/share/zoneinfo/America/Denver /etc/localtime
$ date
$ hwclock --systohc

You can also use ntpdate for NTP (Network Time Protocol)

$ ntpdate pool.ntp.org
$ hwclock --systohc

You will need to restart httpd to see this change reflected in your webserver.

Other Time Links
http://www.time.gov
Network Time Protocol