Rotating addtlnl/auth record
James A Griffin
agriffin at cpcug.org
Wed May 30 10:58:21 UTC 2001
Pawel Rogocz wrote:
>
> Hi,
>
> is there a way to make bind rotate records in the additional/authority
> section when sending a refferal ? It seems no matter what rr-set
> clause is used the records are always send in the same order.
> The problem with that is, when you have subdomains in your domain and
> recursion is turned off, one of your authoritatives for the subdomain will
> get many more queries than the other servers. It is exactly the first one
> listed in your zone file, we can call it "primary" for the sake of
> convinience here. I see ratios of 2.5:1 in number of DNS requests going to
> "primary" vs "non-primary" on a busy site (1500 req/sec) , and it gets
> much worse on sites with less traffic, as the RTT algorithm has no time
> to kick in.
>
> Here is an example:
>
> If you run the following two commands
>
> $dig msn.com a @A.GTLD-SERVERS.NET.
> $dig msn.com ns @A.GTLD-SERVERS.NET.
>
> you will see the first one returns records ALWAYS in the same order,
> the second one rotates them.
>
Try it again. Look at the ';; ANSWER SECTION:' carefully. Note that
msn.com has no 'A' RRs, so the answer section if empty (non-existant).
Answers are rotated (subject to other options).
Regards,
Jim
More information about the bind-users
mailing list