To connect your machine to the CSE network, you must first register your ethernet (AKA "MAC") address. And, to register your MAC address, you need to find it on your machine. This document explains how to do it for the following operating systems:

For others, or if you need assistance, contact support@cs.

Windows

Open a command window and enter the command ipconfig /all. You will get a display like this: 

C:\>ipconfig/all
...
Ethernet adapter El90x1:

        Description . . . . . . . . : 3Com 3C90x Ethernet Adapter
        Physical Address. . . . . . : 00-C0-4F-72-DC-2C
        DHCP Enabled. . . . . . . . : No
        IP Address. . . . . . . . . : 192.168.2.9
        Subnet Mask . . . . . . . . : 255.255.255.0
        Default Gateway . . . . . . : 192.168.2.8
        Primary WINS Server . . . . : 128.95.4.18
        Secondary WINS Server . . . : 198.95.4.19
...

The MAC address for this adapter is 00-C0-4F-72-DC-2C.

Opening a Command Window

Sometimes the pointy-clicky interface just doesn't let you do what you need to do. For those times, there is the command window.

  1. Click on the Start button.
  2. Select "Run." (screenshot)
  3. Enter the word "cmd" into the dialog box that appears. (screenshot)
  4. Click "Okay."

A window will appear in which you can type commands much like to a Unix terminal window. If you are old enough to remember using MS-DOS, you will find that many of the same commands are still supported. You may never go back to point-n-click again!

Renewing Your DHCP Lease

DHCP is a service that is used to manage "leases" on IP (network) addresses. The idea is that when a computer first connects to the network, it requests an IP address from the DHCP service. That address is returned and assigned to the network adaptor, but it's only good for a fixed period of time-- typically a few hours. In the background, a process on your computer renews the lease periodically-- well before it expires. There is a mechanism for your computer to release a lease on a network address before it expires, but the DHCP service doesn't count on it-- your computer might crash or be carried out of range on a wireless network. Therefore, the DHCP service will reassign your IP address to another computer is the lease isn't renewed-- that allows the DHCP service recycle IP addresses efficiently.

Sometimes, you need to explicitly release an IP address and request a new one. That might be necessary, for example, if you move from one wireless domain to another. Fortunately, it's easy to do, using the same ipconfig command that's used to view your MAC address.

  1. To start, open a command window
  2. Enter the command ipconfig/release
  3. Enter the command ipconfig/renew

Each command should return in a few seconds. If not, it typically takes about a minute for the computer to give up attempting to contact a DHCP server that will grant it a lease. If you get an "autoconfiguration" IP address, the renewal has failed. Contact support if you need assistance.

Linux

At a command prompt, enter the command /sbin/ifconfig eth0. The command will return a screen somewhat like this:

% /sbin/ifconfig eth0
eth0      Link encap:Ethernet  HWaddr 00:A0:CC:23:39:3F
          inet addr:142.103.175.109  Bcast:142.103.175.255  Mask:255.255.255.0
          UP BROADCAST RUNNING  MTU:1500  Metric:1
          RX packets:786404 errors:0 dropped:0 overruns:0 frame:0
          TX packets:534006 errors:0 dropped:0 overruns:0 carrier:0
          collisions:47 txqueuelen:100 
          Interrupt:17 Base address:0xf400
The MAC address of this adapter is 00:A0:CC:23:39:3F.

FreeBSD

At a command prompt, enter the command /sbin/ifconfig fxp0. The command will return a screen somewhat like this: 

% /sbin/ifconfig fxp0
fxp0: flags=8843 mtu 1500
        inet 128.95.2.200 netmask 0xffffff00 broadcast 128.95.2.255
        atalk 770.45 range 770-770 phase 2 broadcast 0.255
        ether 00:a0:c9:49:98:5d
        media: 100baseTX  status: active
        supported media: autoselect 100baseTX  100baseTX 10baseT/UTP  10baseT/UTP
The MAC address of this adapter is 00:a0:c9:49:98:5d.

Solaris

At a csh(1) command prompt, enter the command /usr/sbin/arp `hostname`. You will see a screen like this: 

% /usr/sbin/arp `hostname`
hammahamma (128.95.1.115) at 8:0:20:22:e2:be permanent published
The MAC address of this host is 08:00:20:22:e2:be.

MacOS

Open the "TCP/IP" control panel, then go to Edit-->User Mode and select "Advanced." Click the "Info" button in the lower left corner of the dialog box, that's where that information lies.