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

2015-10-20 Thread Phil Mayers
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. Does it periodically send any messages to the server. No. It just sends a query when it has one, and

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

2015-10-20 Thread Reindl Harald
Am 20.10.2015 um 13:26 schrieb Steven Carr: On 20 October 2015 at 10:41, Phil Mayers wrote: On 20/10/15 07:26, Harshith Mulky wrote: 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

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

2015-10-20 Thread Steven Carr
On 20 October 2015 at 10:41, Phil Mayers 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

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

2015-10-20 Thread Harshith Mulky
Hi All, How can a Client verify if the DNS Server is Running(named service is Running) or Down? Does it periodically send any messages to the server. What Kind of messages are required by the client to be sent towards server to determine if the DNS IP is reachable or not? Thanks Harshith

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

2015-10-20 Thread Matus UHLAR - fantomas
On 20.10.15 11:56, Harshith Mulky wrote: How can a Client verify if the DNS Server is Running(named service is Running) or Down? Why should client know such info? The clients needs to have the answer - it sends message and if the server replies properly, it's up and running. Does it

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

2015-10-20 Thread Wah Peng
Hello, Network issue should be detected by other ways. But DNS health check can be done by sending a normal DNS query to the server and try get a valid response. This is the script what I use to check the health of my DNS server. :D #!/usr/bin/perl use strict; use Net::DNS; use POSIX

RE: bind-users Digest, Vol 2230, Issue 1

2015-10-20 Thread Harshith Mulky
named service is > Running) or Down? > Does it periodically send any messages to the server. What Kind of messages > are required by the client to be sent towards server to determine if the DNS > IP is reachable or not? > > Thanks > Harshith >

Re: bind-users Digest, Vol 2230, Issue 1

2015-10-20 Thread Mark Andrews
In message , Harshith Mulky writes: > > No Mark, This is not a question I am asked to answer for some course > > We have an implementation where, once the DNS Servers are down, The > Client (Our device) Blacklists the IP address of DNS Servers for some

Re: bind-users Digest, Vol 2230, Issue 1

2015-10-20 Thread Grant Taylor
On 10/20/2015 08:49 AM, Harshith Mulky wrote: > We have an implementation where, once the DNS Servers are down, The > Client (Our device) Blacklists the IP address of DNS Servers for some > period of Time How long is "some period of time"? Is it something reasonable (read: minutes) or