Subject: Re: Am I using libcares correctly ?

Re: Am I using libcares correctly ?

From: Zan Lynx <>
Date: Mon, 01 Jun 2015 11:55:27 -0600

On 05/27/2015 01:02 PM, Richard wrote:
> Our use of libcares is getting some stability issues especially if
> we use wireless network. libcares will sometimes fail to resolve the
> hostname. Libcares will fail to resolve the hostname within our timeout
> of 60 seconds.

A while ago while doing some DNS related tests I found out that DNS
servers built into things like wireless routers or cell phones with WiFi
tethering often fail when hit with many DNS requests.

I suspect that it has to do with the limited amount of RAM in such
devices. In the cell phone case I am not sure but if the DNS server is
written in Java/Dalvik.

In your situation I would double-check that your wired and wireless
connections are using the same DNS IP addresses. I have seen many
situations where a test was messed up because someone had set a static
DNS address such as on the wired connection but left the
wireless connection set to DHCP only.
Received on 2015-06-01