How can I log how much bandwidth is being used by lookups?

[Kevin Darcy]

Matt Bostock wrote:

>Hi,
>
>I'm running a slave BIND server. How can I monitor how much bandwidth is
>being used by a particular zone? With xfer-log? And how would I set it up?
>
If you want to get a rough idea of how much bandwidth is being consumed 
by zones transfers of a given zone, you could capture what named 
*thinks* it's sending via zone transfers by configuring something like:

logging {
        channel "xfers" {
                file "xfer.log";
                severity debug 8;
        };
        category "xfer-out" { "xfers"; };
};

and then grepping out all of the "transfer of 'xxx.yyy.com/IN': sending 
TCP message of zzzz bytes" messages, but I hope you have a lot of disk 
space, because that high of a debug level actually logs every RR that is 
transmitted via zone transfer as well (!!!), and you can't limit the 
logging by zone, so you get *everything* related to outbound zone 
transfers in the log.

When I say "rough idea", I mean that the "sending TCP message" numbers 
don't include TCP overhead, such as ACKs, retransmissions, and so forth.

                                                                         
                                                      - Kevin