OKay, the other day my ISP’s DNS went down and my browsing came to a screeching halt. This made me aware of DNS issues. I had an iPhone so I searched for Comcast being down and got Google’s display of tweets about the issue. And they said to try using Google’s DNS at 8.8.8.8 After looking up on my iPhone about what the heck that was and how to change it, I did so and my browsing was back on. More importantly, it was fast. Safari was blazing fast though Firefox was still a little slow.
I found a nice program called Namebench which will test all the various public and your own DNServers (why do I always want to expand the last in an acronym, such as ATM machine, DNS server, etc.?) and it confirmed that Google’s was the fastest; I did run that when my ISP was backup. It looks like my ISPs DNS is in Manassas, VA. Is that right?
In case you are interested, it takes roughly a tenth of a second for the round trip for most of the DNS’s I tried, half that for google’s DNS.
So that fixed some of my problems. But I still had more. Firefox was slow. Why? Well, I upgraded to FF4Beta and that did not fix it. I looked into the issue and apparently Firefox checks domains for IPv6 addresses which few use. So it has to receive a fail signal before moving onto the common use case. Now, I don’t understand this at all. I thought the DNS translated words into IP addresses. So why is there another level? But, even though it makes no sense to me, I found that toggling the IPv6 setting in about:config made Firefox respond like crazy.
I was almost done. I still had issues with my sites. That was what the nginx upgrade did with the WP Supercache. Now my sites load blazingly fast.
One last point that I could not track down. From what I could tell, my iMac is not caching the DNS lookups. Why? How do I get it to do so? Is it not good to do so?
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