Mac OS X 10.4.x Network Configuration:
TCP/IP Configuration for Ethernet

This document is part of of Mac OS X 10.4.x Network Configuration, and describes how to configure TCP/IP on a Mac OS X 10.4.x system connected to the campus network with OIT Ethernet wiring.

The Mac OS X 10.4.x Network Configuration documentation covers most common cases. It directs you to this document for a few uncommon situations that require detailed instructions. We assume you have reached this point by following the instructions in that earlier document.

Choosing to Use DHCP

The instructions below include different steps depending on whether you choose to use DHCP, BootP, or manual configuration. DHCP allows TCP/IP to automatically determine most network parameters. (So does BootP, an older service, but it provides less information to your Mac.)

We strongly recommend you choose to use DHCP. Some facilties are only available if you use DHCP.

If you choose to use manual configuration (not DHCP nor BootP), then before proceeding you must:

1. Determine the IP address assigned to your Mac's network interface. If you don't know how, see What IP Address is Assigned to My Mac's Network Interface?.

2. Determine the default IP router and network mask appropriate for your Mac, by consulting Default IP Routers, Network Masks, and Broadcast Addresses. (Note that to look up these values, you will first need to know your network interface's assigned IP address.)

Configuring TCP/IP

1. The System Preferences application should already be open, with the Network pane selected.

   The location you wish to configure should appear in the Network pane's Location pop-up menu. The Show pop-up menu should show the name of your Ethernet port (e.g. Built-in Ethernet), and the TCP/IP tab should be selected.

2. If you do use DHCP service (normally recommended), follow these steps:
   1. In the Configure IPv4 pop-up menu, select Using DHCP.

   2. Make sure the following fields are empty: DHCP Client ID, DNS Servers.

3. If you use BootP service instead of DHCP (not usually recommended), follow these steps:
   1. In the Configure IPv4 pop-up menu, select Using BootP.

   2. Make sure the following field is empty: DNS Servers.

4. If you use manual configuration instead of DHCP or BootP service (not normally recommended except in unusual circumstances), follow these steps to configure your IP settings:
   1. In the Configure IPv4 pop-up menu, select Manually. (Never select Using DHCP with manual IP address.)

   2. In the IP Address field, enter the IP address assigned to your Mac's network interface. This will be a value like: 128.112.aaa.bbb or 140.180.aaa.bbb (your numbers may be different). Before entering it, be absolutely sure you are entering your network interface's assigned IP address, not the address of your default IP router, or another computer's IP address.

   3. In the Subnet Mask field, enter the subnet mask (a.k.a. "network mask", or "netmask") appropriate for your IP address. This will be a value like 255.255.252.0 (your numbers may be different).

   4. In the Router field, enter the default IP router (a.k.a. "gateway") address appropriate for your IP address. This will be value like 128.112.aaa.bbb or 140.180.aaa.bbb (your numbers will be different).

   5. In the DNS Servers field, enter the following three items, one per line (you may enter them in any order):

            128.112.129.32
            128.112.129.111
            128.112.128.1
      

5. Determine your default DNS domain name. This is your Mac's Internet hostname, with the first word (up through the first period) removed. If your Mac is associated with a Dormnet subscription, your default DNS domain name is student.princeton.edu. Otherwise, your default DNS domain name is usually princeton.edu. (A few departments have a different default DNS domain name, e.g. basketweaving.princeton.edu.)

   If your default DNS domain name is princeton.edu, you may leave the Search Domains field blank. (Or you may enter princeton.edu in this field; it will have the same effect.)

   Otherwise, if your Mac's default DNS domain name is not princeton.edu, enter the default DNS domain name first, and princeton.edu next (assuming your Mac hostname ends with princeton.edu). Enter all the names on a single line, separated by commas.

   (If there are multiple DNS subdomains between your Mac's default DNS domain name and princeton.edu, enter each name in the field. For example, if your Mac's hostname is foo.bar.baz.princeton.edu, enter bar.baz.princeton.edu, baz.princeton.edu, and princeton.edu, in that order.

6. Click the Configure IPv6 button to display the IPv6 sheet.

7. In the IPv6 sheet's Configure IPv6 pop-up menu, select Off.

8. Click the OK button to dismiss the IPv6 sheet.

9. Click the Apply Now button.

10. TCP/IP is now configured.