Wireshark Capture Filter - subnet

If you want to capture all data from a specific subnet there is an easy way to do this in Wireshark.  Go into the capture filter screen, create a new filter, name it, and in the filter string space enter the network info using the following format.

net 192.168.1.0/24

Visio Stencils - Cisco

Here is a link to Cisco's Visio stencils.

Visio Stencils

Ping scan with nmap

At times you may just need to be able to find out what IP addresses are currently in use on your network.  One quick way to do this is with nmap.

With Zenmap it's just a matter of selecting the "Ping scan" profile and entering a range in the target field, such as 192.168.1.1-254

If you are using nmap from the command line simply type the following, nmap -sP 192.168.1.1-254

View PAE setting on Windows Server 2008

If you are running the 32-bit version of Windows Server 2008 and have more than 4GB of RAM in your server you may want to know if you are actually running PAE. To do so you can run the following from the Administrator Command Prompt.

"bcdedit /enum | find /I "pae"

It should return something like this if you have PAE enabled.

pae           ForceEnable

Fedora 16

Display running services on Windows

You may already know that you can start and stop windows services using the
net start -service name-
net stop -service name-
commands, but what you might not know is how to simply display what services are currently running. 

This is rather simple and straight forward, simply type the following.
net start

This should display all of the services currently running on your system.  If you have a lot of services running and know the service name you are looking for you can use the following to see if it is running.
net start | find "-service name-"

Windows Server 2008 core - default login

If you are new to installing Windows Server 2008 core you will notice there is a logon screen after the first reboot even though you hadn't previously setup a default password.

To get past this screen, enter administrator as the user name with no password.  After that you will be prompted to change your password.  Once you have set your new administrator password you are good to go.

Find Processes Running On A Remote System

If you're working in a Windows environment and you have the rights to do so, you can find the process running on a remote machine by running the following command.

tasklist /s -machine name-

This will give you important info like the process name, PID, and memory usage.

Wireshark - DHCP filter

If you ever need to capture just DHCP traffic while using Wireshark simply use the following capture filter string.

port 67 or port 68

Fedora 15 Countdown

Scientific Linux - scp missing

I ran across something interesting while working with Scientific Linux 6.  I had done a minimal install and attempted to scp some files over to it from another box.  This fails because the minimal install apparently does not install scp.  If you ran into this as well, the fix is rather simple.

yum install openssh-clients

Windows 7 - MacBook Pro - right click

If you've setup your MacBook Pro to dual boot with Windows 7 you might find it handy to be able to right click without attaching an external mouse.  It feels a little un-natural at first but it's pretty straight forward.

Rest two fingers on the trackpad and click the mouse button.

That's all there is to it.

Disable IPv6 in Debian

As I've posted before that there may be reasons you want to disable IPv6.  A simple way to do this in Debian is to edit /etc/modprobe.d/aliases with the following lines

alias net-pf-10 off
alias ipv6 off

Restart and verify you are no longer running IPv6 by using the netstat command.

netstat -tunlp

Restarting interfaces in Solaris

On occasion you may just want to bring an interface down and then backup up again without actually restarting the network services.  To restart interfaces in Solaris simply do the following.

For the example we'll say and ifconfig -a showed you ce0, ce1, ce2, ce3

To bring an interface down:   ifconfig ce0 down
To bring an interface up:       ifconfig cd0 up