Okay, we're not losing our minds. Bev, if you are on Shaw, I just spoke with the folks there and their simplified explanation is that since early this AM (Tuesday), Shaw's servers are not talking to Yahoo's servers. Apparently they are working on it, and hope to have a solution by tomorrow. I'm just glad to know that it wasn't something I did!
The fact that you could reach Yahoo directly via their IP number indicates this was probably a problem with Shaw's DNS (Dynamic Name System) servers. This is much like a phone book. When you want to place a phone call to somebody you first go to the phone book and look up the number associated with that name, then you dial that number.
The internet is much the same. When you tell the computer to go to www.yahoo.com
, the computer can't go there directly, but first must look up the IP (Internet Protocol) number. Instead of a phone book, your computer consults the DNS server associated with your internet connection, usually provided by your ISP (Internet Service Provider), in this case Shaw. Once the DNS has provided the associated IP number, your computer contacts the internet destination directly, via the IP.
IP numbers are issued, cancelled, and updated all the time. Consequently the local DNS servers must be contually updated. Sometimes something goes wrong with these updates, so until the next update is received, it can leave some internet destinations inaccessible by your system.
If you run into this again, there are a number of things you can do:
- Add an entry in the hosts file on your computer. Your system consults the hosts file before it tries a DNS lookup -- if it finds the IP it needs there, it will use that IP immediately, bypassing the DNS altogether, so it can actually speed up your system for accessing that site. You do have to know the IP number for the site already, though, in order to do this. Here's a TUG post from when we last changed our IP here that contains some more detailed information.
- Configure your system to use an alternative DNS instead of the one provided by your ISP. Here's a list from Broadband Reports of public DNS locations you can use. For fastest results, you should choose ones geographically near you.
One popular alternative DNS is OpenDNS. I've never tried it, but I know folks that swear by it. OpenDNS also provides optional filtering capabilities that allow you to block your choice of over 50 categories of websites (see list). OpenDNS instructions for changing your system DNS configuration.
- Install your own DNS on your computer. The only one I know of is Treewalk.