[c-nsp] Reply:Re: Local DNS cluster behavior

[张建]

Hi Gert，


Thank you for your input.


Actually this behavior is a problem for us.since we have deployed GSLB across our two separated data centers that have the same WWW service which provides services simultaneously to our customers on the internet.still the same scenario in the first email,one customer first time got the DNS response for the server he/she wants to access is located in our primary data center.we want the session established between the customer and the server to be kept and serve the same customer for the data he/she might send later. In the same data center we are able to keep the sessions between clients and servers.but this session was broken due to some unknown issues,so the customer has to request the same service again by sending DNS query.but this time the Local DNS server B got this query and sent it out through IPv6 to the authority DNS.now the problem raises,this IPv6 response may located in our Backup data center.since we are not able to keep the session between two data centers the APP has to send a new connection to the server that is located in our Backup data center.
This is the situation we do not want  to face,however it really depends on how the Local DNS Server work.
So any suggestions will over come it will be very appropriated.


BR
Jiazhan








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----- Original Message -----
From: "Gert Doering" <gert at greenie.muc.de>
To: ???? <ying-xiang at 163.com>
Cc: cisco-nsp at puck.nether.net
Sent: Sun, 6 Dec 2020 10:40:01 +0100
Subject: Re: [c-nsp] Local DNS cluster behavior

Hi,

On Sun, Dec 06, 2020 at 12:11:34PM +0800, ???? wrote:
> Based on the logic above we talked.Is it possible that the first time DNS query sent out by Local DNS Server A using IPv4 to the authority Server,but somehow the second time query by Server B turned out IPv6 query instead of IPv4?

Sure.  Possible, and also fairly likely.

And no problem whatsoever.

gert
-- 
"If was one thing all people took for granted, was conviction that if you 
 feed honest figures into a computer, honest figures come out. Never doubted 
 it myself till I met a computer with a sense of humor."
                             Robert A. Heinlein, The Moon is a Harsh Mistress

Gert Doering - Munich, Germany                             gert at greenie.muc.de