Kitz Forum
Internet => General Internet => Topic started by: Weaver on October 23, 2009, 04:45:26 PM
-
Had any experience of unreliable DNS service from your ISP?
In what way 'unreliable'? What was your experience?
What did you do about it?
Did you try to diagnose/debug it? If so, how?
I have had various experiences of unreliable DNS. With Demon Internet my own primary ISP, and with horrible nameless bargain basement ISPs. I've dealt with it effectively by switching to using external well-known public DNS servers and shunning those of the ISP, or using a mixture of ISP+non-ISP. But I'm ashamed to admit that I've done little to actually get stuck in and debug such issues in the past.
-
Be went through a bad patch some time ago, many people just used OpenDNS.
Got fixed eventually, but some still prefer to use a mix of DNS servers.
-
Be went through a bad patch some time ago, many people just used OpenDNS.
Got fixed eventually, but some still prefer to use a mix of DNS servers.
It's still a problem on the O2 side, current reports on other forums. I always use OpenDNS so the O2 servers don't affect me :D
-
As mentioned above Be/o2's DNS servers at one point had a bad reputation.
I use a mix - in this order
87.194.0.53 (be)
87.194.0.67 (be)
156.154.71.1 (DNS advantage)
208.67.220.220 (OpenDNS)
-
A lot of peeps on the tiscali support forums over the last couple of weeks reported their DNS servers weren't playing, mine was ok though, so don't know how widespread the issue was ......
-
Another solution is to use Treewalk DNS installed on your PC. See http://ntcanuck.com/
It's free and works well for me.
The blurb says Treewalk can help if:
1. Your ISP's DNS servers are slow or offline
2. Accurately resolving web sites is a problem
3. You wish to capture or debug DNS routing data
4. You want to custom configure DNS settings and servers
5. You'd simply like faster repeat visits to sites via cached lookups
6. You have poor DNS with your wireless or satellite Internet connection
7. You use Internet Connection Sharing and want to improve surfing speeds
-
If your ISP's DNS is playing up, there's normally not a great deal you can do beyond moaning at them, and then using OpenDNS or similar.
Troubleshooting whether or not something is actually a DNS issue is reasonably straightforward. For instance, if you're not able to browse to websites just try this from the windows command prompt:
W:\>nslookup bbc.co.uk 212.135.1.36
Server: nscache0.ns.easynet.net
Address: 212.135.1.36
Non-authoritative answer:
Name: bbc.co.uk
Address: 212.58.224.138
Just replace the IP after the domain with your ISP's DNS server to test it. If it responds straight away with the IP of the domain, you can be reasonably sure there's nothing wrong with the server. I'm assuming all versions of windows have native support for nslookup.
If you have access to dig, you can actually do timed DNS lookups like:
core[~]$ dig @212.135.1.36 bbc.co.uk | grep time
;; Total query time: 2 msec
core[~]$ dig @212.135.1.36 bbc.co.uk | grep time
;; Total query time: 1 msec
core[~]$ dig @212.135.1.36 bbc.co.uk | grep time
;; Total query time: 2 msec
core[~]$ dig @212.135.1.36 bbc.co.uk | grep time
;; Total query time: 1 msec
core[~]$ dig @212.135.1.36 bbc.co.uk | grep time
;; Total query time: 2 msec
If dig starts showing query times in the hundreds or thousands of ms, or just times out, you know the DNS is b0rked.