DNS Tweaks (This Is All Very Confusing)

[j79zlr]

If you actually look at the registry values my tweak changes it just disables the caching of failed lookups, and not regular DNS caching. I know Firefox and IIRC IE will cache DNS lookups for a current session, so while the browser is open it will not continue to send identical DNS requests in the same session unless the cache is already full.

I know Bold is looking to slim down everything in XP, disabling the DNS client service is perfectly safe. If you want to disable it to save some memory, it does not hurt anything, if you want to keep it running, using my tweak will disable caching failed lookups.

[Bold_Fortune]

I see it, Budman. But we did get off on a thing about the pros and cons of the DNS Client. So I could have lost it there.

I know you know what you are talking about, Budman. But like I've always said, "When you don't know for sure, you should trust the expert you feel most comfortable with...because computer experts are like a bunch of stock brokers all pointing in different directions."

I'm not in away meaning to take away anything from you. You are obviously very knowledgeable. But in this case I need to go with the expert(s) whom I feel the most comfortable with.

I have known j79zlr for some years now. He and mnosteele are considered pretty much the cats pajamas when it comes to Cablenut and Internet tweaking.

So, I need to go with those whom I feel the most comfortable.

Thank you very much for your input, though.

[+BudMan MVC]

Whatever dude - I could really care less what you do with your machine.. if turning off the dns client to save a few bytes of ram.. blows your skirt up - more power too ya ;) But the service provides a VALUABLE function.. yeah its going to take some memory to do that.. If you feel that your machine will preform better with the few extra extra bytes of memory vs doing queries across the WAN to a DNS server that is being hit by every other user of that ISP.. your welcome too it..

does your browser cache queries.. I am not 100% sure - and that surely could depend on the browser in use, and its settings.. But sure it would make sense to not have to query during the same session.. IE an example of the WHOLE POINT of a local dns cache.. ;)

But really, whatever your browser does is besides the point of turning off the service.. It comes down to, does your machine have to query an outside machine every time it wants to look up www.neowin.net, or does it look to it own cache for it...

Does not really matter what application your using, nor what its own caching functions provide.. If your OS is asked to look up something - does it have to go across the wire and ask again.. If it was just told by your dns server that whatever IP address is good for the next ? amount of time? Or does it look to its own local cache?

I still can not see any point to turning this service off - not one! If your machine makes DNS queries.. it makes sense to cache them for the length of the TTL.. How does it NOT make sense to cache them? If I tell you that you can reach me at some phone number for the next 2 hours.. you do not need to call me 5 minutes later and ask me where you can reach me.. So I can tell you the same number for the next hour and 55 minutes.. Then call me again 30 minutes later..... So I can TELL you the SAME thing...

What your doing is throwing the whole TTL system out the window - and just saying every time I need the address of something.. I'll just ask the owning server for it....

I really am interested in your performance increase with turning this service off.. It must be atleast measurable?? What is the % of your performance increase due to turning off your dns client?? Its quite easy to "measure" the difference in dns queries to your ISP.. A simple log of dns over a given period of time will show the benefits of caching vs not...

[Bold_Fortune]

As usual, valid points, BudMan. Again, thanks for your input.

Although, I think I'll keep DNS Client disabled on my machine. ... It just kind of blows my skirt up, you know what I mean.

[mayamaniac]

I found this thread with the search tool.

Anyway, I have a stubborn XP machine that refuses to update the DNS, it keep picking up the old IP of a DNS. I tried ipconfig /flushdns and that didn't seem to have any effect even though it says it performed successfully.

I also tried the registry settings here on the first post and rebooted multiple time and it still doesn't update the IP. I even disabled the DNS Client service and yet it still doesn't work.

Any more ideas?

[.AlleymaN]

Check your HOSTS file...

[mayamaniac]

Check your HOSTS file...

all is see in that file is:

127.0.0.1 localhost

so anymore ideas?

[NiceCarpet]

Try a different ISPs DNS server

I had the same problem, my ISPs DNS server would take days to reload new IP's so I changed to an others DNS server (iHug, New Zealands from Xtra, New Zealand) and all went well the site I was trying to see loaded _b.

[mayamaniac]

Try a different ISPs DNS server

I had the same problem, my ISPs DNS server would take days to reload new IP's so I changed to an others DNS server (iHug, New Zealands from Xtra, New Zealand) and all went well the site I was trying to see loaded _b.

I have a few computers behind a router with a DHCP server, and all the other computers does not have this problem. Only one computer refuses to flush its dns cache. When I ping a domain on the other computers, I get the correct IP. But on the problem computer, I get a completely different outdated IP. And as I said before, I've done all the things posted here, and rebooted multiple times, and it still pings to the wrong IP.

So far, the workaround is I added the correct IP and domain name to the "Hosts" file and that fixed it. But still curious to why it doesn't refresh the dns on its own.