Recommendations for DNS

Tue Sep 22 10:33:44 CEST 1998

I was hoping the SOA values recomended would be reduced particuaraly the ttl to
increase convergance with the implementation of notify's. I agree the refresh
and the retry realy do not nee to change that much but having such a high TTL
means the dns will not converge for up to 24 hours. This means that the dns
reocmendaed convergance time overall has not changed. What is the point of
using notify's if the resolvers are not going to keep up. Just my thoughts.

 Stephen Burley                                
 Senior HOSTMASTER for UUNET(UK)              
 Internet House                         
 332 Science Park, Milton Rd.        
 Cambridge                         
 CB4 4BZ                                        http://www.uk.uu.net

       Todays weirdness is tomorrows reasons why.

On 22-Sep-98 Hans Niklasson wrote:
> Greetings
> 
> This is the action point from RIPE-28 thats in the final stage.
> I will be presenting this at RIPE-31 this Thursday.
> So any comments and suggestions will be looked at if they arrive before
> Thursday.
> Otherwise I4ll see you there. :)
> 
> 
>                               DNS recommendations.
>  
>  
> By:
>  
> Hans Niklasson <hasse at swip.net>
> Amar Andersson <amar at telia.net>
>  
>  
>  
> Scope: 
>  
> This documents act as a recommendation for configuring your DNS. This is
> NOT a requirement, only a recommendation of things to think about when
> setting up your DNS.
>  
> Purpose:
>  
> To decrease lame delegations and limit unecessary traffic due to resolving
> problems, among other things.
> To have a document for LIR:s to use for their customers instead of a
> number of RFC:s.
>  
>  
> Records:
> -----------------------------------------------------------------------------
>  
> SOA      The address in this field must be a valid e-mail address to the
>          administrator for the DNS.
>          It's also good practise to have role address instead of
>          personal, ie root.. admin.. hostmaster.. 
>          (when domain-administrator is leaving your company, you 
>          only change the alias for role address).
>  
> Ex:
>  
> foo.bar.com.        IN      SOA     dns.foo.bar.com admin.foo.bar.com 
>  
>  
> SERIAL   Serial number should follow this format: YYYYMMDDXX 
>          ( year.year.year.year.month.month.day.day.nr.nr ),
>          where XX is the number of the latest update of the zone in the 
>          same day. (Year 2000 is near.)
>  
> Ex:
>  
>                   1998010101      ; serial
>  
>  
> TTL      A good balance of this will reduce unecessary traffic between
>          nameservers.
>  
> Ex:
>  
>                   28800   ; refresh (8 hours)
>                   7200    ; retry (2 hour)
>                   1209600 ; expire (14 days)
>                   86400 ) ; minimum (1 day)
>  
> MX       When pointing a domain to a mailserver/hostname, do not forget
>          to add a record ( A ) for this.
>  
> Ex:
>  
> foo.bar.com.        IN    MX      10 mail.foo.bar.com.
>  
> mail.foo.bar.com.   IN    A       192.168.0.1
>  
>  
> CNAME    Use this with caution. It is *not* recommended to use a CNAME
>          for a mailservers hostname, as this can cause resolving problems
>          and mailloops. Also it is not a good thing to use CNAMES on
>          nameservers as this will cause unnecessary traffic on the net.
>  
> A        A record can only point to an IP address.
>  
>  
> PTR      This is used for reverse lookup of the IP address to a hostname
>          within the zone. Make sure that your PTR records and A records
>          match. For each A record there has to be a PTR record, and vice
>          versa.
>  
>  
> More tips:
>  
> Unecessary glue data:  
>         
>         Do not add unecessary glue data about hosts that is not within
>         the zone. This can cause resolving problems if the host changes IP
>         address.
>  
> Ex:
>  
> foo.bar.com.        IN    MX      10 mail.foo.bar.com.
>  
> mail.foo.bar.com.    IN    A       192.168.0.1
>  
>  
> Trailing dots: 
>         Do not forget to add a "." at the end of the domain/
>         hostname. If this is forgotten, this will make the DNS to add the
>         domain name to the domain/hostname again. This will cause
>         resolving problems.
>  
> Ex:
>  
> 11      PTR     foo.test
>  
> will produce   foo.test.7.42.666.in-addr.arpa.
>  
>  
> Illegal characters: 
>         
>         Only a-z , 0-9 and - is valid to use. 
>         The domain system allows a label to contain any 8-bit character.
>         Although the domain system has no restrictions, other protocols
> such
>         as SMTP do have name restrictions.  Because of other protocol
>         restrictions, only the above characters are recommended for use
>         in a host name (besides the dot separator). 
>  
>  
> General Points:
>  
>         Use the latest version of the DNS software for your platform.
>         Check for updates regulary, as new versions has the latest
>         solutions and information.
>  
>  
> Example on a recommended DNS:
>  
> foo.bar.com  IN    SOA     ns.foo.bar.com. root.foo.bar.com. (
>                         1998081900      ; serial
>                         28800   ; refresh (8 hours)
>                         7200    ; retry (2 hours)
>                         1209600 ; expire (14 days)
>                         86400 ) ; minimum (1 day)
> foo.bar.com.  IN    NS    ns.foo.bar.com.
>  
> foo.bar.com.    IN  NS    ns2.foo.bar.com.
>  
> foo.bar.com.  IN    MX    10 mail.foo.bar.com.
>  
> www.foo.bar.com.  IN  CNAME www.webhotel.xx.
>  
> www2.foo.bar.com. IN    A       192.168.0.3
>  
> ns.foo.bar.com.   IN    A       192.168.0.1
>  
> ns2.foo.bar.com.  IN    A       192.168.0.4
>  
> mail.foo.bar.com. IN    A       192.168.0.2
>  
> localhost       IN    A       127.0.0.1
>  
>  
> Additional reading and references:
>  
>         RFC1537 ( RFC1912 )
>         ( Common DNS Operational and Configuration Errors )
>         
>         RFC1033-5
>  
>         RFC2181
>  
>         "DNS & BIND 3nd Edition" by Paul Albitz & Cricket Liu 
>         from OReilly & Associates Inc.
>         
>         ftp://ftp.ripe.net/internet-drafts/draft-ietf-dnsind-classless-
>         inaddr-04.txt
>         ( For reverse delegation methods for blocks smaller than /24,
>         256 addresses )
>  
>         http://www.dns.net/dnsrd/
>         ( DNS Resources Directory )
>  
> 
> 
> /Hans Niklasson
> 
> -----------------------------------------------------------------
>               SWipNet - The Swedish IP Network
> 

 Stephen Burley                                
 Senior HOSTMASTER for UUNET(UK)              
 Internet House                         
 332 Science Park, Milton Rd.        
 Cambridge                         
 CB4 4BZ                                        http://www.uk.uu.net

       Todays weirdness is tomorrows reasons why.