> -----Original Message----- > From: Anand Buddhdev > Sent: Sunday, March 30, 2003 6:06 PM > Subject: Re: NameServers, DNS, and BIND > > > On Sun, Mar 30, 2003 at 01:39:18PM -0600, Cowles, Steve wrote: > > > > If you have only one host and it's your nameserver as well as > > > your mail server, why add redundancy? If the nameserver is > > > down, so is the rest of the domain. It's not up to the > > > registrars to tell you how to configure your domain. > > > > Point taken - at least the part about the registrars > > responsibility. But it seems like back when I registered > > my first domain (1996/Network Solutions) I don't remember > > being able to register the same IP for both name servers. > > Maybe I just didn't try hard enough. Anyway, I have since > > moved away from network solutions. > > > > As for redundancy/failover... I run my own DNS/Mail server > > on the same box. If my end goes down, its nice to know that > > my secondary DNS server (located in another state) will still > > answer DNS queries for my domains and queue e-mail for later > > delivery. i.e. No DSN is sent. So my domain names are not > > "totally" down even though I have a single point of failure > > at my end. > > Not true. If your mail server is down, what good is a secondary DNS > server going to do by answering with MX and A records for the downed > server? The clients will receive the records, try to connect, get a > timeout, and queue the mail for later delivery (and they may generate > DSNs, which you cannot control). This is hardly different from having > a single DNS server which has failed, because in that case, the SMTP > client will get a soft DNS error from its resolver, and still queue > the mail (and possibly generate a DSN which is not in your control). >
After re-reading my post, I can see how you might have misunderstood my point on redundancy. Let me clarify! I also have a backup MX server listed in my dns talbes (lower priority and located in another state) that receives e-mail when my end goes down. So... 1) The secondary DNS server answers dns requests for my domains if my end goes down. 2) Because I have a backup MX server listed, the initial connect to my mail server will obviously fail, but will be accepted by the backup MX server. The backup MX server is configured to queue all e-mail (not retry delivery or issue DSN's). When my end comes back on-line, I issue an ETRN against the backup server to release the queued mail (cronjob). So no DSN's are ever issued. Steve Cowles -- redhat-list mailing list unsubscribe mailto:[EMAIL PROTECTED] https://listman.redhat.com/mailman/listinfo/redhat-list
