Curtailing Chicago Recursive Domain Name Service Access
On June 14, 2006, NSIT will limit Domain Name Service (DNS) to machines on campus. This will have no effect on the vast majority of the University community. However, a very few people may have problems if their off-campus machines are misconfigured. This page contains information about how to tell if you will be affected, and links to more information for those who are interested.
- How to tell if you're affected...
- ...if you're running Windows
- ...if you're running Mac OS X
- ...if you're using a home wireless or Ethernet router
- ...the hard way, on June 14 or later
- How to fix your configuration
- What's actually happening (non-technical)
- Frequently Asked Questions (technical)
How to Tell if You're Affected
Who Will NOT Be Affected
- On-campus users
- Off-campus users who dial in to the University
- Off-campus users who explicitly configure their machines according to instructions provided by their internet service provider (ISP)
If you're familiar with network settings: Check your DNS server settings. If any of them start with 128.135, and you access the internet through third-party provider such as SBC/Yahoo!, Comcast, AOL, etc., you will need to change your DNS settings to match those provided by your ISP. Detailed instructions for checking your machine's DNS follow below.
If you are running Windows XP...
(These instructions assume you have a cable modem or DSL connection and are connecting over Ethernet. If you are dialing in to your provider, these instructions may not work.)
- Go to Start → Connect To → Show All Connections
- Right-click on your network connection and select "Properties"
- In the "This connection uses..." listing, double-click on "Internet Protocol (TCP/IP)"
- If "Use the following DNS server addresses" is checked, and the DNS servers listed start with the numbers 128.135, you are using the University's DNS servers and must change them according to your ISP's instructions.
If you are running Mac OS X...
(These instructions assume you have a cable modem or DSL connection and are connecting over Ethernet. If you are dialing in to your provider, these instructions may not work.)
- Go to System Preferences → Network
- From the "Show" menu, select your network interface (e.g. "Built-In Ethernet")
- If the "DNS Servers" box lists addresses starting with the numbers 128.135, you are using the University's DNS servers and must change them according to your ISP's instructions.
If you are running a wireless router at home...
...you will need to check the DNS configuration on the router. Unfortunately, the details on how to do this vary according to the router, so we cannot provide comprehensive instructions for this; consult your router's manual for details.
If you've waited until after June 14th...
If you are one of the few people who need to change their DNS configurations, and you wait until after June 14th before checking, it will be very obvious that something has happened. If you suddenly find that you can access websites and other services in the uchicago.edu domain, but can't access anything else (probably with a "not found" or "does not exist" error of some kind), then you need to change your DNS settings according to your ISP's instructions.
How to Fix Your Configuration
Generically, to fix this problem, you either need to replace the University DNS servers you currently have listed with your ISP's DNS servers, or set your machine to obtain DNS server addresses automatically. Which one of these options you choose, however, depends on your ISP, as do the specific DNS servers you need to list (if you need to list any).
Tip if you can't find support
If you're set to obtain an IP address automatically (Windows) or to configure via DHCP (Mac OS X), try setting your machine to obtain DNS server addresses automatically (Windows) or leaving the DNS Servers field blank (Mac OS X). This will almost always be the correct configuration, especially in hotels, Internet cafes and public wireless spaces.
The links below will take you to the configuration instructions provided by the four most common ISP's used by the University community -- SBC/Yahoo, Comcast, Earthlink, and RCN. Unfortunately, we cannot comprehensively list instructions for the huge number of providers used beyond those four; so if you're using one of those smaller providers, you'll have to contact them for detailed instructions. (If you aren't sure how to contact your provider, check your bill — there will usually be contact information listed.)
Please note that our support for manually configuring DNS settings can be limited and relies on outside information.
Last updated: 10/03/06
