In order to download and install the newest IOS 5.1 update, I had to change my DNS Server settings in my Network preferences to 8.8.8.8 and 8.8.4.4
It actually seems like my browser loads pages faster as well. One thing I notice is that Xmarks is not doing it's thing for Safari.
I'm not very knowledgeable of DNS settings and what they're all about. Is there any reason why one shouldn't mess with their DNS Server settings? What is the Default? 192.168.1.1?

csonni, the settings you are now using are the Google Public DNS server. You may find better (or worse) performance using your ISP's default settings (don't enter anything, it will be automatically assigned), or OpenDNS' servers: 208.67.222.222 or 208.67.220.220 ...and there are others out there... :)

Quick review: The DNS (Domain Name System) is the table which relates the name of the website you type in ( like ehmac.ca ) with the actual internet IP address of the server where that website lives (72.52.243.84) Without DNS, you would have to remember the IP numbers for each website - not good. DNS is a distributed system, there are many DNS servers, and they are linked together to share/update the latest updates and new website addresses.

The default DNS server would be the one provided by your broadband service provider, typically on their servers. This is communicated to your broadband modem and then on to your router. When your Mac attaches to the router by DHCP ("Get settings from Router") then the router will send the DNS server address to the Mac on login. That's the normal, automatic way to set it up.

By putting in Google's DNS server address 8.8.8.8 manually, you are bypassing the automatic method, and instructing the Mac to query the Google DNS server directly. In some cases this can solve problems, if the ISP's DNS server is slow or has bad entries or (rarely) has been poisoned by a virus. Google promotes their public DNS system as being faster and more secure.

The other option is to use the OpenDNS servers OpenDNS - Cloud Internet Security and DNS (http://www.opendns.com/)
IP address:
208.67.222.222
208.67.220.220

There's a DNS utility "namebench" you can try and have a look and see what info it can show and suggest for possible alternate servers:
namebench - Open-source DNS Benchmark Utility - Google Project Hosting (http://code.google.com/p/namebench/)

I just had to change the DNS settings on my Apple TV to get it to load the most recent update (just as I did on my Mac to update our iPads). Is it a better idea to go into my Airport Extreme Base Station and change the DNS settings there? Will that cover everything else? I found a bit on this here:

OpenDNS Community > Forums > AirPort Extreme Base Station with 802.11n -- any problems? (http://forums.opendns.com/comments.php?DiscussionID=150)

"While the Airport Extreme N accepts custom DNS configuration (e.g., OpenDNS) it does not distribute the configured DNS to DHCP clients. I've tested with both Windows and OS X clients and both are not receiving custom DNS from the Airport.

There are a number of comments on the Apple Discussions site related to this problem (not just an OpenDNS problem)."

By putting in Google's DNS server address 8.8.8.8 manually, you are bypassing the automatic method, and instructing the Mac to query the Google DNS server directly. In some cases this can solve problems, if the ISP's DNS server is slow or has bad entries or (rarely) has been poisoned by a virus. Google promotes their public DNS system as being faster and more secure.
The other option is to use the OpenDNS servers OpenDNS - Cloud Internet Security and DNS (http://www.opendns.com/)
IP address:
208.67.222.222
208.67.220.220

Excellent review, CanadaRam!
Some more: in Belgium, even before the actual ratification of ACTA (if they ever get to it, hope not), we are denied access to e.g. The Pirate Bay whilst using most local DNSs. Not that I am an actual user, this is is just my decisive test case. Using Google DNS or Open DNS, The Pirate Bay still stays wide open.
So it seems the choice of DNS server also decides on how restricted/ controlled your Internet communication actually is...
The problem is, in some cases you have to change the DNS settings directly in your router/ access point. Changing them in your Mac's System preferences> network will not be effective. And with some ISPs, you will not be able to do this at all!

What is the Default? 192.168.1.1?
Certainly not, csonni: this is most probably the ip of your main router! Do not touch!
For DNS, please read the rest of this interesting thread.
In order to define your settings, please check system preferences>network>advanced

So then, it's okay to change the DNS settings in your router/modem (not IP Address)?

I've never done so, but yes, theoretically it is OK. But, as posted above, with some ISPs it will be impossible. As is the case with mine.
Moreover, I think you will also have to change the settings in system preferences>network>advanced>DNS. People tell me if you put in multiple DNSes, it is unclear whether Mac OSX will treat the topmost in the list, or the downmost in the list as your prioritary DNS. So you might want to experiment with the order of your list. Good luck, or should I say "speed"...

That's very strange to hear, I've been using OpenDNS for years,
I've never had to change the settings for any updates from Apple or anyone else.

As I've already posted, this seems entirely to depend on your ISP. You may be one of the lucky...
My ISP does seem to keep even the distribution of Dynamic IPs in hand, or I have to throw in an extra router... And no way to change my DNS server. Thats the way it goes in Belgium...
And ACTA will be worse even.
PS:"While the Airport Extreme N accepts custom DNS configuration (e.g., OpenDNS) it does not distribute the configured DNS to DHCP clients. I've tested with both Windows and OS X clients and both are not receiving custom DNS from the Airport."
This seams to mean you even have to set your devices to manual IPs. What a Jungle!

That's very strange to hear, I've been using OpenDNS for years,
I've never had to change the settings for any updates from Apple or anyone else.

This is old news... I beleive Apple doesnt use DNS query anymore since last year.

The DNS (Domain Name System) is the table with the name of the site you (as ehmac.ca) with the Internet IP address of the server where the site (72.52.243.84) Without DNS, you would must consider the IP numbers for each site to remember - not good. DNS is a distributed system, there are many DNS servers, and they are linked together to share / the latest updates and new Internet addresses to work.