[ILUG] Class C Addresses

[Paul Jakma]

On Wed, 7 Nov 2001, John P. Looney wrote:

> > course even better solution is DNS SRV records. very fine grained load 
> > balancing - client side.
> 
>  Never heard of them. What's that then ted ?

http://www.faqs.org/rfcs/rfc2052.html

service.protocol	SRV	priority weight target

eg:

http.tcp		SRV	10 30	mainwww1.foo
			SRV	10 30	mainwww2.foo
			SRV	10 30	mainwww3.foo
			SRV	10 10 	lesserwww.foo
			SRV	20 60	backupwww1.foo
			SRV	20 40    otherwww.far
			SRV	30 0	lastresort.far

service - well known service name
protocol - tcp or udp (but some ferkin idiots thought it'd be clever 
to use _tcp and _udp -> active directory and more.. same for service, 
eg "_http". arg....)

priority is like MX priority. lowest one is preferred. eg above, 
client will only contact the priority 20 server /if/ the prio 10 
servers are not available.

the weight determines the proportion of queries a target within a 
priority should be given.

so in above, normally mainwww{1,2,3} will have queries balanced 
between them, with a smaller amount of queries going to lesserwww.

if they're not available, try backupwww1.foo and otherwww.far.

if none above available, try lastresort.far.

all above is done client side. and clients that dont support SRV will 
obviously not make use of it.

> Kate

--paulj