How does a Client Verify if the DNS server is Alive or down

[Steven Carr]

On 20 October 2015 at 10:41, Phil Mayers <p.mayers at imperial.ac.uk> wrote:
> On 20/10/15 07:26, Harshith Mulky wrote:
>>
>> Hi All,
>>
>> How can a Client verify if the DNS Server is Running(named service is
>> Running) or Down?
>
>
> By the presence or absence of a reply to a query.

That doesn't always verify if the server is running or not, your
client might not be allowed to query it, in which case you may get a
refused response, or it may just not respond to you at all.

Steve