Date: Mon, 26 Oct 2009 15:14:47 -0500 From: "Gary Gatten" <Ggatten@waddell.com> To: "Gary Gatten" <Ggatten@waddell.com>, "Ray Still" <rstill74@gmail.com>, <freebsd-questions@freebsd.org> Subject: RE: bind configuration issues Message-ID: <22794_1256588088_4AE60338_22794_16_1_70C0964126D66F458E688618E1CD008A08CCEE85@WADPEXV0.waddell.com> In-Reply-To: <21272_1256584114_4AE5F345_21272_1_1_70C0964126D66F458E688618E1CD008A08CCEE7C@WADPEXV0.waddell.com> References: <19358_1256579715_4AE5E283_19358_105_1_70C0964126D66F458E688618E1CD008A08CCEE70@WADPEXV0.waddell.com><5e09dc040910261155t641ae7bbu79bc08d735d69db6@mail.gmail.com> <21272_1256584114_4AE5F345_21272_1_1_70C0964126D66F458E688618E1CD008A08CCEE7C@WADPEXV0.waddell.com>
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I googled "dns round robin failover" and there are many hits. One interest= ing one is: http://forums.devshed.com/dns-36/ha-using-round-robin----working-368800.html It suggests well written apps / resolvers will try to use all ip's returned= by the query starting with the preferred one, not JUST the preferred one. = Which means, just by enabling round robin with multiple A records, you MAY= get some level of HA/Failover by default. Cool, BUT, I wouldn't bet my li= fe on it. I'd still have something that could tweak your DNS records based= on packet loss, latency, etc. What if your circuit is "up", but is degrad= ed by loss, latency (load induced or otherwise), etc. As you mentioned, something is better than nothing - so start simple and go= from there! HTH! G -----Original Message----- From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd-questions@f= reebsd.org] On Behalf Of Gary Gatten Sent: Monday, October 26, 2009 2:07 PM To: Ray Still; freebsd-questions@freebsd.org Subject: RE: bind configuration issues I'm not intimate with bind, or anything/one actually - but that's another s= tory... Anyway, the gist is you need to "ping" some public hosts from your dns serv= er (or another system I guess, but easier if on the dns server). One desti= nation host would be reachable through one connection, and the other of cou= rse would only be reachable through the alternate connection. Maybe use th= e primary DNS servers each upstream ISP provides to you? Anyway, if both p= ings are OK, then your DNS server does round-robin for the host(s) in quest= ion. If one ping fails, then you stop handing out that IP. You can for th= e route taken within ping itself, or use static host(/32) routes, etc. Sounds simple huh? It kinda is, and LONG ago I had a shell script to do ju= st this, but it's gone - and maybe bind 9+ has some sort of this functional= ity available to you embedded in the bind code? Don't know. Even if you h= ave to write your own script to update your dns records based on your monit= oring process it's not that hard even for a scripting novice such as myself! G -----Original Message----- From: owner-freebsd-questions@freebsd.org [mailto:owner-freebsd-questions@f= reebsd.org] On Behalf Of Ray Still Sent: Monday, October 26, 2009 1:56 PM To: freebsd-questions@freebsd.org Subject: Re: bind configuration issues On Mon, Oct 26, 2009 at 11:55 AM, Gary Gatten <Ggatten@waddell.com> wrote: > > You certainly don't "need" BGP for this, the DNS thing will work, but wil= l be a bit kludgy and certainly not as ... "responsive" to failures - a la = query caching, TTL's and what not. > > ----- Original Message ----- > From: owner-freebsd-questions@freebsd.org <owner-freebsd-questions@freebs= d.org> > To: Ray Still <rstill74@gmail.com> > Cc: freebsd-questions@freebsd.org <freebsd-questions@freebsd.org> > Sent: Mon Oct 26 12:50:56 2009 > Subject: Re: bind configuration issues > > On Oct 26, 2009, at 10:03 AM, Ray Still wrote: > > Hello, > > I am adding a redundant Internet connection to my current hosting > > setup and > > I need to figure out how to set up the DNS to make this work. > > The two issues normally aren't related. > > If both connections are from the same provider, talk to them about > multilink PPP; if they are from different providers, you need to look > into multihoming and getting your own AS #. > two different providers. > > > Current setup: > > freebsd 7.0 machine, one local IP address, runs web, mail, and name > > server. > > static ip address in router. > > I have two DNS servers registered, but they both point to the same ip > > address an the same machine. (Yes, I should have my fingers slapped.) > > > > Desired setup > > same machine, one local IP address, runs web, mail, and name server. > > different router (Linksys RV082) with 2 static ip address. > > In order to have redundancy, you need to have two real, separate > machines, each of which is running BIND, each of which is on a > separate routable IP.=A0 This is an orthogonal issue to setting up > multiple Internet connections. Yes, In an ideal world I would do this. The two machines would also be in separate buildings/cities/provinces/countries/planets (pick your level of paranoia)=A0 ;) However, reducing single points of failure is an improvement, even if I can't eliminate them. > > > How do I set up bind so that > > 1) bandwidth is shared between the two connections, > > and > > 2) if one goes down, the other keeps working. > > I had a few ideas, but they all seem to have flaws. > > You can't set up BIND to control multilink aggregation and failover; > that's not what it does. > > Regards, > -- freebsd-questions@freebsd.org > -Chuck > Thanks for the replies. Chuck, thanks for the keywords to search. Some of what I'm finding looks like a solution for companies a lot bigger than me, but I'll keep looking. Gary, can you give me any clues about how to do it with just DNS? Yes, I do realize that this leaves single points of failure, but at least they would be points that I could do something about if necessary. Thanks again, Ray > > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to "freebsd-questions-unsubscribe@freebsd.o= rg" > > "This email is intended to be reviewed by only the intended recipient and= may contain information that is privileged and/or confidential. If you are= not the intended recipient, you are hereby notified that any review, use, = dissemination, disclosure or copying of this email and its attachments, if = any, is strictly prohibited. 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