[Samba] nameservers, all DCS??

[L.P.H. van Belle]

I dont understand whats the question here. 

But what i can say about the resolv.conf settings if you have multiple dc's. 

You have to think in 2 DNS resolving settings. 

1) on the server as client resolving ( resolv.conf ) 
2) clients resolving ( DNS Services ) 

The difference explained.  
If i do : ping hostname   this is a server which is doing a client dns request through resolve.conf
If i do : dig A hostname @DNSSERVER  this is a server which is doing a client resolving request through dns services. ( port 53 ) 

In case of 2 DCs. 
Before the join of second DC, point the resolv.conf to DC1. 
After the join of the second DC, and after the reboot of the server, this changes a bit. 
Change resolve.conf to 
Nameserver IP_OF_DC2   ( NOT LOCALHOST ) ! 
Nameserver IP_OF_DC1   
(optional add a internet DNS server, if both DC's fail you server can still use the internet ) 

DC1 should now  have 
Nameserver IP_OF_DC1   ( NOT LOCALHOST ) ! 
Nameserver IP_OF_DC2
(optional add a internet DNS server, if both DC's fail you server can still use the internet ) 


A 3 DC setup. 
Same as the 2 DC setup, but add the third to it. 

A 4+ DC setup. 
Here i preffer the following, the DC with FSMO roles in this example is DC1. 
DC1 resolv.conf DC1 first, then what you want. 
DC2 resolv.conf 
	DC2
	DC3
	DC4 

DC3	resolv.conf
	DC3
	DC4
	DC2

DC4	resolv.conf
	DC4
	DC2
	DC3 

Etc etc 

And i advice this also in resolv.conf if you run multiple dc.s 
# resolv.conf its timeout is 5 sec by default, to long imo.
options timeout:2
# round-robin selection of name servers from among those listed
rotate 

Why no localhost in the resolv.conf, that can give problem with kerberos things. 
Localhost =! Hostname 


Greetz, 

Louis

    

> -----Oorspronkelijk bericht-----
> Van: samba [mailto:samba-bounces at lists.samba.org] Namens 
> Denis Cardon via samba
> Verzonden: vrijdag 25 mei 2018 11:59
> Aan: Carlos; samba at lists.samba.org
> Onderwerp: Re: [Samba] nameservers, all DCS??
> 
> Hi Carlos,
> 
> > About order Dcs in resolv.conf
> >
> > DC(LOCAL)
> > DC(OTHER)
> 
> that is what we do here. You'll find some articles about DNS 
> islanding 
> (for example [1]) that would recommend to do differently, but if you 
> happen to have the issue mentionned in those articles, you 
> can actually 
> fix it by hand easily.
> 
> > I send same question in April:
> >
> > https://lists.samba.org/archive/samba/2018-April/214957.html
> 
> unfortunately there is no one paid on this list to answer your 
> questions... If no one is inspired or have time or have will 
> or have the 
> knowledge, then there may be no answers (which is actually 
> not so common 
> on this list).
> 
> Cheers,
> 
> Denis
> 
> [1] 
> https://support.microsoft.com/en-us/help/275278/dns-server-bec
> omes-an-island-when-a-domain-controller-points-to-itself
> 
> > About Replication, is KCC....
> >
> > I send question im May
> >
> > https://lists.samba.org/archive/samba/2018-May/215636.html
> 
> 
> >
> >
> > Regards;
> >
> >
> >
> > On 24-05-2018 18:43, Carlos Bordon via samba wrote:
> >> hi!
> >>
> >>
> >> Query, I have 3 DCs, in each of the servers should have 
> configured the
> >> other two DCs in the resolv.conf?
> >>
> >> or with only the primary is enough?
> >>
> >> Maybe that's my problem that does not replicate the dc3 
> with the dc2
> >>
> >> thanks to all!
> >
> >
> 
> -- 
> Denis Cardon
> Tranquil IT Systems
> Les Espaces Jules Verne, bâtiment A
> 12 avenue Jules Verne
> 44230 Saint Sébastien sur Loire
> tel : +33 (0) 2.40.97.57.55
> http://www.tranquil.it
> 
> Samba install wiki for Frenchies : https://dev.tranquil.it
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> 
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