HowTo-Locate My IP Address (2024)

The IP address is a unique 32-bit identifier given to a computer for use on the network. Without the IP address, communication is not possible. In Logan Hall, IP addresses are assigned statically, by the LSP. Options for automatic assignment through DHCP is available for AirSAS wireless clients. All IP addresses are given in a numeric format commonly called "Dotted Decimal Notation" .

Example: 192.168.0.1

The addresses used in Logan Hall have the numbers 130 and 91 for the first two sections, or "octets". Computers in Fiji House (3619 Locust Walk) have the numbers 165 and 123 in their first two octets. All computers require an IP address to connect to the Internet. TCP/IP (Transmission Control Protocol / Internet Protocol) is a suite of network protocols, of which the IP address, is the functional unit.

TCP/IP can be installed on any type of computer. Every device that connects to the Internet has an IP address at some level. Both Microsoft Windows, and Apple Mac OS X have numerous ways to determine the current IP address.

Mac OS X (10.4 Tiger): Network Utility.

1. Open the Utilities folder from inside the Applications directory (Shift-Command-U).
   
2. Double-click the "Network Utility" application and allow it to open.
   
3. The first section of the window is the "Info" section. A drop-down menu allows the user to select which adapter they would like to view. Airport adapters are known as "en1" and the Ethernet port goes under the designation "en0".

See Also

Change TCP/IP settings - Microsoft SupportDetermine Your Private and Public IP Addresses from the Command Line | Linux Training AcademyFinding the Host Name, IP Address or Physical Address of your machine | School of Medicine ITProbing Remote Hosts With the ping Command

Mac OS X (10.4 Tiger): ifconfig

1. Open the Utilities folder from inside the Applications directory (Shift-Command-U).
   
2. Double-click the "Terminal" application and allow it to open.
3. A console window will appear. From the prompt, type "ifconfig en1". If the address assigned to the built-in ethernet port is sought substitute "en0" for "en1".
4. The IP information for the given adapter will be displayed in the terminal's console window after the "inet" descriptor.

Windows XP (All Versions): Local Area Connection Status

1. From the desktop, navigate through; Start > Control Panel > Network Connections > Local Area Connection .
2. Right-click the local area connection and choose "Status", then click the "Support" tab. The "Details..." button reveals even more information about the connection's IP information.

Windows XP (All Versions): ipconfig.exe

Windows Vista (All Versions): Network and Sharing Center

1. From the desktop, navigate through; Logo > Control Panel > Network & Internet > View Network Status and Tasks. This will open the "Network and Sharing Center".
2. Select the "Connection" > "Local Area Connection" then the "Status" tab. The "details" buttonwill provide the IP address and connection information.

Windows Vista (All Versions): ipconfig.exe

1. From the desktop, navigate through; Logo > type "cmd.exe" in the "Start Search" dialog box . A command prompt window will appear.
2. At the prompt, type "ipconfig". All IP information for all network adapters in use by Windows will be displayed.

Additional Items

Every IP connection has additional information that is associated with it's operation.

The subnet mask is an another 32-bit number that identifies what network the IP address belongs. Computers with IP addresses on the same subnet can talk to each other natively. IP addresses with different subnet masks must communicate through a translating device such as a router to exchange information. A common example of a subnet mask is;

255.255.255.0

The subnet mask for all IP addresses in use at Logan Hall is 255.255.252.0 and 255.255.255.128 for all of the addresses in Fiji House.

Default gateway is the IP address of another computer that acts as the exit ramp for all traffic leaving the network. The most common use for a default gateway is to allow computers on the network to access the Internet. Corporate environments use a "proxy server" as a default gateway to filter and protect outgoing network traffic.

The default gateway address for Logan Hall is 130.91.236.1 and 165.123.54.1 for Fiji House.

Every computer with an IP address needs the IP address of a DNS server to resolve names of web-sites on the Internet. Without a proper DNS server and the correct subnet mask, a computer will not be able to access the Internet. All computers on-campus use the same DNS server addresses. Three DNS server addresses are provided for load-balancing and redundancy. These addresses only work while on-campus and not off-campus.

The Penn DNS servers are 128.91.2.13, 128.91.254.1, and 128.91.254.4.

- Jason Watkins, 9/2/2007