Round Robin and "MX" type records

[Mark_Andrews at isc.org]

	If the MTA's are doing the correct thing the load will be 
	distibuted evenly without round robin support as they are supposed
	to randomly pick between even value Mail eXchangers.

	BIND 4.9.3 round robins all types except PTR record if round robin
	it turned on.

	Mark

	P.S. You are using a very old BIND version containing may security
	flaws.

> Hello DNS Folks!
> I received a request today to implement "round-robin" load sharing on
> selected MX records soon to be in my DNS. I have done the "round-robin"
> thing before using "A" and CNAME" records, but never using the "MX" record
> type. Although I could have overlooked it, I have yet to see this activity
> referenced in any RFC, FAQ or newsgroup as it pertains to MX records.
> However, the "DNS and BIND" O'Reilly book (2nd edition, pg 212) states "(In
> fact, the name server will rotate any type of record, not just address
> records, as long as a given domain name has more than one of them.)"
> 
> My questions are:
> 1. Is this a feasible way to do informal load sharing across multiple Mail
> Exchanger hosts? 
> 2. Does it violate any standards?
>    
> 
> We are using bind4.9.3 on AIX 4.2.1 and I envision the following:
> myemail.domain.gov                     3600 IN  MX  0
> mailserver1.domain.gov
> myemail.domain.gov                     3600 IN  MX  0
> mailserver2.domain.gov.
> 
> -----------------------------------------------------------
> Dave Luiz - Network Management Unit 
> State of California - Health and Welfare Data Center
> Phone: (916)-739-7703                
> Fax: (916)-454-7232                  www
> mailto:dluiz at hwdc.state.ca.us       (@ @)    
> -----------------------------ooO-(_)-Ooo--------------------
> 
> 
> 
--
Mark Andrews, Internet Software Consortium
1 Seymour St., Dundas Valley, NSW 2117, Australia
PHONE: +61 2 9871 4742                 INTERNET: marka at isc.org