On Tue, Apr 16, 2002 at 12:16:51PM +1000, Ben Donohue wrote: > Hi Slugs, > While on the subject of mail servers... > My understanding of mail secondaries is that it's not like DNS servers where > you can config a client to access a secondary DNS server if the primary is > down. The secondary MX only stores the email until the primary is back up. > It then fowards the email to the primary. the clients check with the primary > only for their email. Is this correct?
I think so, although there is the etrn smtp command you can send to your secondary site to make them spool the mail to you immediately if you don't want to wait until their next retry. > Is there a way to make some sort redundant mail server where you have two > setup and the client will respond to either one? or is this clustering? that's kind of covered by the "weighting" field in MX records. Eg. 'dig -t mx adam.com.au' shows ;; ANSWER SECTION: adam.com.au. 18h12m18s IN MX 10 eden.adam.com.au. adam.com.au. 18h12m18s IN MX 20 postoffice.telstra.net. meaning try eden.adam.com.au then failing that postoffice.telstra.net, 10 is a higher weighting/priority then 20. You can go mad putting in as many as you like. To get a sort of load balancing effect I guess you can put several machines all at the same priority. I don't know if it would work just guessing here. > A third question. Is it considered good practice to have your own secondary > MX on site if you also look after your own primary MX? Or just let the email > queue on sending servers if your primary goes down? well that's what the discussion has been about, search back a few weeks for the replies to my thread on the subject of secondary mx's. If you have a secondary on the same site as your primary then it covers you if the primary goes down but not if your site is cut off from the net. You could then have a tertiary mx that is off site of course. Or you could not have any. Dave. -- SLUG - Sydney Linux User Group Mailing List - http://slug.org.au/ More Info: http://lists.slug.org.au/listinfo/slug
