Tuesday afternoon about 4:30, I lost Internet access. A call to my ISP, AT&T, verified that the link itself was open. I immediately suspected a DNS problem. I tried to ping Google.com, but the DNS lookup failed.
Suspicions confirmed, but was the problem with my local DNS server, or with AT&T? I pinged several local computers, and DNS operated as expected. I invoked nslookup, set the server to 220.127.116.11, and tried to resolve Google.com. No dice. I tried the alternate AT&T DNS server, 18.104.22.168, with the same result. I called AT&T tech support, but they refused to help me, saying that DNS problems were handled by a different team. I called back, and pressed the menu selection keystrokes to get the DNS team, but I got a message saying that they were closed for the day, and that I should call back in the morning.
When I purchased T-1 service from AT&T, I thought I’d get 24/7 tech support. Now I know that, while they may offer round-the-clock tech support for the connection itself, support for DNS access is much more limited.
I didn’t want to wait until the next day for a working Internet connection, so I pulled out my Verizon connected iPad, and walked around the house looking for a bar. Access was painfully slow, but I did manage to find out that Google operates a free, public DNS service.
I went to the configuration screens for the local DNS, and added 22.214.171.124 and 126.96.36.199 – nice easy to remember IP addresses – to the DNS forwarders list. I was in business.
After a few minutes, the AT&T DNS servers spring back to life.
I’d lost an hour and a half, and missed the ImageMakers meeting, but I learned a valuable lesson. The Google DNS server addresses are going to stay in my forwarders list. I suggest you add them to yours. You can read more here. There are other independent DNS servers. One of the most popular is OpenDNS. They offer a range of services, from free and basic to more exotic features for improved privacy and security. You can read about OpenDNS here.