🚀 go-pugleaf

Cydrome Leader <presence@mungepanix.com> wrote:

> Can somebody else explain what the point of the weird crashing wireless 
> network with one dns server is again?


It's OSX, and it's two dns servers, and it came in with version 10.8 from
last summer. It also seems to have been carried over to ios, for the
iphones, ipads and ipods, to a certain degree.

For whatever reason, it seems to effect the MacBooks more than anything
else, over wifi.

Basically the general thinking is, when the dhcp server gives the two ip
addresses for the name server to the device, if web browsing around you hit
a lookup that returns servfail (which normally occurs on a reverse lookup)
instead of nxdomain, what happens is, the device doesn't accept the servfail
and queries the other, gets the same, goes back to the first, gets the same,
goes to the secondary, creating a loop of lookups.

It seems like it's more on the router handing the dhcp, I guess some gives
the router address (it's own) for both dns servers, some gives one external
and itself, some pass along the isp's upstream ones.

The ones that give itself are the ones that fail, the macbook floods the
thing with dns requests because it's stuck in the dns query loop. Some of
the routers crap out, some lock out the device as an attack, some reboot.

Many people who started to have a problem like, wifi works for 10-15 minutes
then I have to reboot the router or macbook to get another 10-15 minutes
have solved it by changing the issued dns servers for dhcp to a single
address.

I guess when the macbook sees the single address for dns and gets the
servfail, it accepts it as the truth. With 2 dns servers available it never
accepts it as true.

Honesty though, I've never seen anyone mention this as an ipv6 problem,
thus, this probably isn't the same thing as Anderson is seeing but sounds
related.

-bruce
bje@ripco.com