"reverse dns must have a matching forward entry..."
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aharown07
MemberI've been following this great tutorial step by step. Everything going quite well until I got to setting up rdms.
First, the link was hard to find at Linode because it isn't under Network anymore. Found it under Remote Access.
Real problem though: the "reverse dns" screen already displays a "current reverse dns" and when I key in my mail.mydomain.org and hit the "look up" button, I get an error...
"• No match was found for 'mail.blahblah.org'. Reverse DNS must have a matching forward entry that points to one of your IPs."I don't know what this means. Ideas? Thanks!
Posted 1 year ago # -
aharown07
MemberDocumentation (here: http://library.linode.com/dns-guides/configuring-dns-with-the-linode-manager ) says I need an A or CNAME record for my entry. I checked the DNS page and there appears to be an A record there. So--can't imagine what gives here.
Posted 1 year ago # -
First, the tutorial was written when the RDNS setting was under network; or more specifically, when the Linode manager as you see it today was only in beta, so this is the reason you found it in Remote Access.
Second, this means that your domain mail.domain.com doesn't have it's A record pointing to your VPS IP. Where is the domain registered? Just because you add the domain as a master on Linodes system doesn't mean the domains DNS settings are going through Linode's system; unless you change the NS for the domain at the registrar.
Posted 1 year ago # -
aharown07
MemberWon't that take the site offline? I don't even have mysql or nginx installed. It's likely to be days before there is any site for the domain to point to if I switch them to Linode at the registrar.
Why doesn't the tutorial say this is necessary if it is?
Also, after editing /etc/hostname and /etc/hosts the command hostname -f no longer works. It says
"hostname: Name or service not known"
I'm thinking some things have change since the tutorial was made... and these are breaking it.Posted 1 year ago # -
aharown07
MemberLooks like the solution may be here...
http://vpsbible.com/forums/topic/problem-w-hostname-fWill try in the morning
Posted 1 year ago # -
That's fine and dandy, but let me clarify, without you changing the A record for mail.domain.com, your RDNS will never work.
You don't, of course, have to change your NS yet, only the A record for mail.domain.com needs to be changed.
The point of the error message your getting is that the DNS is not resolving for mail.domain.com, and it wont unless you make it point to whatever the IP address of your VPS is. Merely typing mail.domain.com into your RDNS form does nothing without either Linode managing your DNS records (which requires you adding your domain as a master then changing your NS to Linodes nameservers) or making an A record for mail.domain.com pointing to your Linode.
I'm sorry to be redundant in this message, but unless we're not on the same page, that post your linking to wont have the answer for you.
When you type in a domain into the address bar, the first thing the browser does is check for the name servers, which then sends off the DNS records to do whatever they do (a non-techie way to explain it), so unless you're pointing your 'mail' DNS record somewhere, wherever your domain is registered (the DNS is managed) doesn't know what to do with it. This is why Linode is telling you that there is no matching forward entry, and it's going to keep telling you that.
Posted 1 year ago # -
aharown07
MemberOh, I think we had a misunderstanding there. There is already an A record as far as I can tell. Did that in the previous step in the tutorial.
The problem was that the Linode RDNS tool didn't seem to be seeing the A record.
...and might still not be seeing it.
Not done trying this other recipe yet.Posted 1 year ago # -
aharown07
MemberOK, the hostname -f thread I linked to does solve that problem but apparently is unrelated to the "must have a matching forward entry" problem.
I'm guessing there is something wrong with the A record I made, then.
I'm not sure what it ought to look like.
(Is it possible that something still needs to propagate?)Posted 1 year ago # -
aharown07
MemberRootoor... got some help from Linode support. Turns out that while it should be possible to set up the A record for mail.etc.com without changing where the DNS points at my registrar, it isn't in this case because they've got a CNAME record that conflicts... or somethig like that.
Short version: I can't do this part of the tutorial w/o repointing my domain afterall.So now the question is, as far as you know--or anyone else who wants to chime in--can I do the rest of the tutorial without the reverse dns set up and/or without postfix?
Can you foresee any problems with coming back and setting that part up later?
I'd like to get as much done as possible before I take that site offline.
Posted 1 year ago # -
V A
MemberI've got a similar question and situation to aharown07 (i.e. following steps on http://vpsbible.com/email/setup-postfix-email/ I get the "No match was found" for the RDNS entry) except my domain's mail is already hosted on Gmail.
I've been trying to set this up on Linode but, like aharown07's experience, it seems some steps were skipped or assumptions made in these very good tutorials. (Sorry; complete newbie here).
I'm trying to not disrupt the Gmail account unless I have to for no more than a few hours.
(1) Is there a way to get the VPS mail settings working while keeping Gmail active as I expect to take the site down a few times while testing?
(2) Please explain, in my case, where to get the A Records and CNAME (registrar, Gmail, Linode, etc.)?
I should note that I reviewed the process Linode instructs in its forum (http://library.linode.com/email/google-mail) and, as you may see, many Linode users are struggling with variations of this problem.
Many thanks to anyone who can help.
Posted 10 months ago # -
hi VA, "No match was found" is likely due to the DNS taking time to trickle through. Can be a couple of days, maybe 3, from a nameserver change at the domain name registrar.
Gmail .. you mean Google Apps?
Once set up, your MX records (for mail) are unaffected by you taking the site down, provided the nameservers are pointing to the same IP.
As for the DNS setup, this is covered in the tutorial. Actually though, this points to Google's documentation because the setup varies from host to host.
Posted 10 months ago #
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