Snow Leopard mini having DNS issues

I'm seeing the same intermittent DNS problems on a brand new MBP that I upgraded to Snow Leopard immediately after opening. My other MBP that's still running 10.5.8 in the same environment is working fine. Renewing my DHCP lease fixes it for a while.

I have almost the same setup and issue as the original poster (SL-running Mini, 10.5.8 DNS server, other 10.5.8 machines working fine, etc.). nslookup is returning the correct information, but ping is not.

I was able to fix the issue for an couple of hours by rebooting my 10.5.8 DNS server, but now the issue is back.

Same issue here. Nslookup can resolve the IP on my Ubuntu server, but anything else (ping, ssh, etc) and I get nothing. It's also shutdown all the SSH keys on my keychain because they're stored with the hostname, not the IP.

Need some help here Apple...

Can you open the Terminal application and type "scutil --dns" and hit return, and post the results.

I may have a partial answer which I'm testing out on my own 10.5.8 DNS server. It looks like 10.6 tries to get DNS lookups over IPv6, and is not falling back to IPv4 like it should. Try disabling IPv6 on your internal DNS server's network interface, so that the only response your 10.6 Mac is getting is using IPv4.

After a couple of hours, the DNS lookups started failing again so it looks like IPv6 being enabled or disabled on the DNS server is not the root of the problem.

Snoop:

Here's my output, the first listing (resolver #1) is my router. It's running Tomato and has DNS forwarding and caching:

DNS configuration

resolver #1
domain : local
nameserver[0] : 192.168.1.1
order : 200000

resolver #2
domain : local
options : mdns
timeout : 2
order : 300000

resolver #3
domain : 254.169.in-addr.arpa
options : mdns
timeout : 2
order : 300200

resolver #4
domain : 8.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300400

resolver #5
domain : 9.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300600

resolver #6
domain : a.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300800

resolver #7
domain : b.e.f.ip6.arpa
options : mdns
timeout : 2
order : 301000

-ksudeadeye

ksudeadeye, what's the domain name of the server you're trying to connect to?

Snoop:

This is my local network domain. I'm trying to connect to my Ubuntu server from my Macbook. Here's some terminal output from nslookup and ping on the Macbook:

nslookup phatty-server
Server: 192.168.1.1
Address: 192.168.1.1#53

Name: phatty-server.local
Address: 192.168.1.140

ping phatty-server
ping: cannot resolve phatty-server: Unknown host

OK. The reason for the failure is that you're using ".local" for your private domain but Mac OS X uses ".local" for Bonjour. You should avoid using ".local" for your own private domain, and instead you should switch to some other TLD, like ".home" or ".lan" or ".private" or anything else, as long as it's not ".local". If switching would be too much work, there's another workaround you can do. Make sure there's an SOA record in your DNS zone file that answers for "local.". In other words, verify that running this Terminal command returns an SOA record in the answer section of the response.

dig -t soa local.

If it returns NXDOMAIN, it means you haven't done it right. Configuring an SOA record in your zone file will tell the Snow Leopard machine that you're using "local" for unicast DNS on your network, and then the machine will query for "local" names using regular DNS in addition to Multicast DNS.

Hope that helps.

It looks like my issues may come down to my having split DNS on my 10.6 client, with DNS server entries for both my internal DNS server as well as OpenDNS's DNS server. I've removed the OpenDNS server entries from my 10.6 mini (I already had the Open DNS servers set as forwarders on my 10.5.8 server) and we'll see if the DNS works properly now that it can only look at one DNS server.

scutil (with both internal and OpenDNS DNS enabled):

DNS configuration

resolver #1
search domain[0] : mydomain.net
nameserver[0] : 192.168.1.70
nameserver[1] : 208.67.220.220
nameserver[2] : 208.67.222.222
order : 200000

resolver #2
domain : local
options : mdns
timeout : 2
order : 300000

resolver #3
domain : 254.169.in-addr.arpa
options : mdns
timeout : 2
order : 300200

resolver #4
domain : 8.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300400

resolver #5
domain : 9.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300600

resolver #6
domain : a.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300800

resolver #7
domain : b.e.f.ip6.arpa
options : mdns
timeout : 2
order : 301000



scutil (with only internal DNS enabled):

DNS configuration

resolver #1
search domain[0] : mydomain.net
nameserver[0] : 192.168.1.70
order : 200000

resolver #2
domain : local
options : mdns
timeout : 2
order : 300000

resolver #3
domain : 254.169.in-addr.arpa
options : mdns
timeout : 2
order : 300200

resolver #4
domain : 8.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300400

resolver #5
domain : 9.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300600

resolver #6
domain : a.e.f.ip6.arpa
options : mdns
timeout : 2
order : 300800

resolver #7
domain : b.e.f.ip6.arpa
options : mdns
timeout : 2
order : 301000

Hi rtrouton. Yep, I think you're right. If you really want all DNS queries to go to your own DNS server at 192.168.1.70, then you should not put any other DNS addresses into the Network pref pane.

I'll try changing the local domain.

Thanks.

Previously, I was getting blank screens on my internal websites after installing Snow Leopard. I disabled IPv6 on the client (Snow Leopard), and things are working fine now. If things break again, I'll come back to this thread 🙂 I hope this helps

I have a similar issue. My local DNS server handles all lookups (resolves addresses for local domain locally and forwards other queries to my ISP's DNS server).

Queries for non-local lookups always succeed, however queries for local domain will succeed only the first time and fail on second attempts.

Using Nslookup works all the time, but any command that uses gethostbyname (i.e. ping) will succeed once (tcpdump shows a correct lookup to local dns server), but will fail the 2nd time (no lookup to dns server visible in tcpdump).

On a sidenote, it looks like host lookups are not cached (since they do not show up in dscacheutil)
(all lookups result in a cache miss).

I tried turning IPv6 off/on but this does not change anything.

(first part of ) Output of scutil --dns

DNS configuration

resolver #1
domain : munnik.net
nameserver[0] : 192.168.1.121
order : 200000