Post deleted by Pipexer

In reply to a post by Oliver341:

In reply to a post by tommy45:

Yes UkOnline's DNS servers where flakey as where BE 's out of the two BE's where far worse, at that point i stopped using ISP's DNS servers

Possibly I was already with Sky when any DNS problems with O2/BE started.

There were some severe issues for a couple of days then response times were a bit naff for a few weeks. Nothing most people were likely to notice given that most modern OSes cache requests anyway. I find that the external content providers are the worst because they often have very short TTLs. An advert blocker can address that by preventing the need to look up a lot of the 'fly by night' content addresses

In reply to a post by bgriffiths:

I use two of the fastest servers listed by DNSbench in the router for general family use, my laptop has the four fastest (with no more than two from the same provider)

I doubt DNS response speed matters anywhere near as much as reliability. For most processes it's something done once when the session is established and never again. If you download 1GB of data that's not going to result in millions of DNS queries. If you're playing a game I'd expect one query on game start-up (or perhaps when you join in a shared game). After that it's just data streaming between sockets and no need for a DNS query - same as when you make a phone call. You only need to look the number up once at the start of the call.

And most modern OSes can cache queries (Windows by default, Linux I think only if you configure it). Exactly how long a domain stays cached depends on the TLL. Some are short, some are long.

bbs.adslguide.org.uk
----------------------------------------
Record Name . . . . . : bbs.adslguide.org.uk
Record Type . . . . . : 1
Time To Live . . . . : 78735
Data Length . . . . . : 4
Section . . . . . . . : Answer
A (Host) Record . . . : 80.249.99.126

So that will stay in my cache for nigh-on 24 hours. But others only sit in the cache for a few seconds. Actually the above record is a bit odd because there's also this in my cache:

forums.thinkbroadband.com
----------------------------------------
Record Name . . . . . : forums.thinkbroadband.com
Record Type . . . . . : 1
Time To Live . . . . : 139
Data Length . . . . . : 4
Section . . . . . . . : Answer
A (Host) Record . . . : 80.249.99.126

I access the forums by typing 'bbs...' in the address bar which is probably why it's in the cache but it's a bit odd that the two TTLs are so different considering they resolve to the same address.

But anyway the only people I think should worry about query speed are the server operators. For them it's clearly an important performance metric as it relates to the number of queries the server can field. But for us as users - I just don't see any need to obsess about it. DNS queries are probably some insignificant %ge of the total network traffic and optimising them is unlikely to have any impact on my experience. As long as the response comes back within half a second I doubt we'll care.

Actually a second thought on the subject is that if you're using public DNS servers you might not get localised results. A couple of web articles talk about this. You could save a couple of milliseconds on the initial lookup but then lose many milliseconds talking to servers on the other side of the planet instead of servers closer to your location.

So overall I say don't worry about it. There are other optimisations that will have far more of an impact so if your ISP's DNS servers have never actually let you down leave them be. Don't needlessly complicate your network configuration. I use OpenDNS as a backup on my mail server but that's the only machine that overrides the router/ISP settings.

Edited by Andrue (Mon 10-Mar-14 11:50:18)

In reply to a post by Andrue:

so if your ISP's DNS servers have never actually let you down leave them be

Guess that means everybody on just about every ISP needs to be looking at alternatives then because every ISP I've been with (and that is a lot) has had DNS issues at one time or another.

Having a router that lets you override the ISP servers is, imo, a distinct advantage as trying others if you get problems is a moments work. The google ones are dead easy to remember too if the ones you have are hard failling and can't search for alternatives. If they fail reverting to ISP is easy too.

Edited by kwikbreaks (Mon 10-Mar-14 13:55:07)

In reply to a post by kwikbreaks:

so if your ISP's DNS servers have never actually let you down leave them be

Guess that means everybody on just about every ISP needs to be looking at alternatives then because every ISP I've been with (and that is a lot) has had DNS issues at one time or another.

You've been less lucky than me and I suspect others then. There were a couple of days when Be's servers were flaky (one of their customers was flooding them with queries and became one of the few people to actually get kicked off the service as a consequence). But I can't think of any time other than that. No doubt sometimes they ran a bit slow (Be's did all around that time and they ended up creating new ones) but it was only visible if you actually ran a monitoring tool.

But yeah if you're with an ISP that has dodgy DNS by all means use the public ones. My only dispute is with the idea that choosing different DNS servers is a good way to speed up your connection. I reckon that in 99% of cases it doesn't make the slightest noticeable difference to anything and if it does it's as likely to slow things down as improve them.

Edited by Andrue (Mon 10-Mar-14 15:24:17)

I'd agree with your arguments about speed. I probably don't often venture beyond sites where the DNS result isn't already cached in my PC anyway. I'm not saying that ISP DNS is especially problematic but I think I've seen the odd problem with just about every ISP I've ever used.

I liked the idea of setting the router up with the ISP's DNS plus any spare slots with public ones.

I've currently got my router set to use OpenDNS because my wife has banned the granddaughters from using Facebook while they are here and that offers a cheap and cheerful filter. I noticed that filtering at URL level on the router didn't work for HTTPS. I've manually set my PC to use google DNS so I can look in on Facebook to check if they've also bypassed the DNS fltering.

Because I wasn't using PN DNS servers I've had none of the grief with them that I've seen reported.

SNPT no longer synchronising (?) on PN servers 212.159.6.9, 212.159.6.10, 212.159.13.49 and 212.159.13.50 had to use 130.88.200.4 (Manchester University ntp2d.mcc.ac.uk) on my TG585 v7 router to successfully set a time server...

Just checked my router log:

Mar 11 10:35:43 SNTP Synchronised again to server: 212.159.13.49

In reply to a post by jelv:

Just checked my router log:

Mar 11 10:35:43 SNTP Synchronised again to server: 212.159.13.49

Thanks jelv - I've been using 212.159.6.9 for more than a couple of years with xilo/uno (TTB SMPF) and my TG585 v7's without any problems but a few days ago it stopped working and I couldn't get 212.159.6.10, 212.159.13.49 and 212.159.13.50 to synchronise either.