This has only happened while visiting my parents, but this is second time.

Suddenly my web sites do not load. I get directed to:

http://guide.opendns.com/main?url=www.s ... &servfail=

It says the following nameservers are running but not resolving my host:

Nameserver trace for www.shastaherps.org:

Looking for who is responsible for root zone and followed i.root-servers.net.
Looking for who is responsible for org and followed a0.org.afilias-nst.info.
Looking for who is responsible for shastaherps.org and followed ns4.linode.com.
Nameservers for www.shastaherps.org:

ns2.linode.com
ns1.linode.com
ns4.linode.com
ns3.linode.com

I can ssh in though, so the server itself is live.

What causes it, and short of running my own nameservers for it, how can I prevent it in the future?

I suspect I may have never seen it at my house because I use a local caching DNS server, so if this happens frequently with the linode DNS servers, i don't know, but if it does, it is unacceptable.

Anyone know more about this?

I can ssh into my development server (hosted elsewhere) and use links to access it, so it appears it may be a problem with the nameserver of the ISP my parents use??

None of my linode hosts are resolving, but other hosts are.

Yup, changed my nameserver to 8.8.8.8 (google public) and it all works dandy, so this must be an issue with whatever DNS is assigned by my parents wireless router.

Bugs the hell out of me though, does that mean my site can not be accessed from time to time from people who use opendns, while other sites can?

Looks good from here:

$ dig +trace www.shastaherps.org

; <<>> DiG 9.3.2 <<>> +trace www.shastaherps.org
;; global options:  printcmd
.                       33167   IN      NS      m.root-servers.net.
.                       33167   IN      NS      a.root-servers.net.
.                       33167   IN      NS      b.root-servers.net.
.                       33167   IN      NS      c.root-servers.net.
.                       33167   IN      NS      d.root-servers.net.
.                       33167   IN      NS      e.root-servers.net.
.                       33167   IN      NS      f.root-servers.net.
.                       33167   IN      NS      g.root-servers.net.
.                       33167   IN      NS      h.root-servers.net.
.                       33167   IN      NS      i.root-servers.net.
.                       33167   IN      NS      j.root-servers.net.
.                       33167   IN      NS      k.root-servers.net.
.                       33167   IN      NS      l.root-servers.net.
;; Received 417 bytes from 205.133.7.2#53(205.133.7.2) in 236 ms

org.                    172800  IN      NS      c0.org.afilias-nst.info.
org.                    172800  IN      NS      a2.org.afilias-nst.info.
org.                    172800  IN      NS      d0.org.afilias-nst.org.
org.                    172800  IN      NS      a0.org.afilias-nst.info.
org.                    172800  IN      NS      b2.org.afilias-nst.org.
org.                    172800  IN      NS      b0.org.afilias-nst.org.
;; Received 439 bytes from 202.12.27.33#53(m.root-servers.net) in 373 ms

shastaherps.org.        86400   IN      NS      ns1.linode.com.
shastaherps.org.        86400   IN      NS      ns2.linode.com.
shastaherps.org.        86400   IN      NS      ns3.linode.com.
shastaherps.org.        86400   IN      NS      ns4.linode.com.
;; Received 119 bytes from 199.19.53.1#53(c0.org.afilias-nst.info) in 240 ms

www.shastaherps.org.    86400   IN      A       72.14.177.39
shastaherps.org.        86400   IN      NS      ns4.linode.com.
shastaherps.org.        86400   IN      NS      ns3.linode.com.
shastaherps.org.        86400   IN      NS      ns1.linode.com.
shastaherps.org.        86400   IN      NS      ns2.linode.com.
;; Received 199 bytes from 69.93.127.10#53(ns1.linode.com) in 200 ms

You'll have to ask OpenDNS what the problem is. Linode's nameservers have been extremely reliable in my experience. Looks like OpenDNS is resolving properly now:

$ dig www.shastaherps.org @208.67.222.222

; <<>> DiG 9.3.2 <<>> www.shastaherps.org @208.67.222.222
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 14910
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.shastaherps.org.           IN      A

;; ANSWER SECTION:
www.shastaherps.org.    85914   IN      A       72.14.177.39

;; Query time: 4159 msec
;; SERVER: 208.67.222.222#53(208.67.222.222)
;; WHEN: Sat Apr  2 19:04:26 2011
;; MSG SIZE  rcvd: 53

$ dig www.shastaherps.org @208.67.220.220

; <<>> DiG 9.3.2 <<>> www.shastaherps.org @208.67.220.220
; (1 server found)
;; global options:  printcmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 16077
;; flags: qr rd ra; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:
;www.shastaherps.org.           IN      A

;; ANSWER SECTION:
www.shastaherps.org.    85883   IN      A       72.14.177.39

;; Query time: 148 msec
;; SERVER: 208.67.220.220#53(208.67.220.220)
;; WHEN: Sat Apr  2 19:04:52 2011
;; MSG SIZE  rcvd: 53

This also happens to me quite often when using OpenDNS. If you are quick enough and click on the detailed error link, it will say that one or more of the Linode DNS servers had a SERVFAIL error.

This has been happening for a few months now. I've simply ignored the error and just re-entered the URL to get around the OpenDNS error. Simply refreshing the page does not work due to the OpenDNS URL redirection 'feature'.

I've also been having this problem. It's very strange as I'm sharing a linode with multiple sites and randomly only one may not work suddenly for awhile.

For example, I'm using OpenDNS servers (and so are millions of potential visitors) and today (4/4/11) creativeculturemedia.com won't come up, but spiritlakepublishing.com will, and they are on the same servers, same domain servers, nothing is different, but one work and the other doesn't.

Does anyone know what can be done? I tried the refreshcache at opendns.com to no avail. Thanks.

Ask people why the hell they're using opendns' known to be unreliable servers?

Since when is OpenDNS unreliable? Or are you just referring to this?

_________________
Matt Nordhoff (aka Peng on IRC)

I've been using OpenDNS for well over a year and have had no problems at all.

So far, every link I click on when searching google for "opendns unreliable" claims just the opposite....

personal experience with lots of similar problems like this one led me to dump it and go with google whenever I hit wonky DNS in various hotspots (which happens way more often than you'd think)