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Re: UDP packet/DNS server

  • From: Roeland M.J. Meyer
  • Date: Wed Sep 30 01:52:19 1998

Yeah, and if you do then sendmail will be broken, according to the v8.9.1
dox. It's called a wild-card MX record and is specifically not recommended,
more than once, in the sendmail dox. I actually had NetCom tech support
recommend it once, then I found out why it's not recommended, the hard way.
When it comes to DNS, you're *much* better off by being specific, even if
it means being verbose.

At 10:39 AM 9/30/98 +0900, Tatsuya Kawasaki wrote:
>Eric,
>
>thank for your reply. Though I did not agree with RFC  I understand
>what you are saying. 
>Do you think it is about time to change RFC?  
>
>BTW, according to NDS and BIND 2nd Ed. by O'Reilly, it is okay for
>MX record too. :-)
>
>TIA,
>Tatsuya
>
>$B$+$o$5$-(B
>TK3197
>
>= = = = = =
>Business Network Telecom (BNT)
>$B%S%8%M%9%M%C%H%o!<%/%F%l%3%`3t<02q<R(B
>$B")(B111-0053$B!!El5~ETBfEl6h@uAp66(B3-8-5
>31$B;35~%S%k(B6$B3,(B
>TEL 03-5687-3945   FAX 03-5687-6009
>http://www.giganet.net
>
>On Tue, 29 Sep 1998, Eric Sobocinski wrote:
>
>> But it's perfectly ok for PTR records, though perhaps your example is less
>> than ideal.  The objection to the use of "*" was specific to NS records.
>> An NS record should exist for a domain only if that domain exists.  Since
>> "*" matches any subdomain whether the domain exists or not, an NS record
>> will be returned for non-existent subdomains and that violates the rule.
>> Some records of other types are incompatible with "*" for similar reasons.
>> The major point here is that any DNS record should reference either a valid
>> response or another record that will lead to a response, and an NS record
>> pointing to a zone file that doesn't exist is neither.
>> 
>> Some folks will contend that the use of "*" in PTR records is bad form even
>> though it is legal.  That's a religious war, not a technical one.  (I
>> happen to like the use of "*", though I also believe that one should first
>> apply specific host names whenever a static mapping allows).
>> 
>> 
>> On Monday, 28 Sep 1998 at 21:02 EDT, Eric Germann wrote:
>> >
>> >you have to admit, it does save one hell of a lot of typing for the 1918
>> >IN-ADDR.ARPA delegations.
>> >
>> >rfc1918.db
>> >----------
>> >
>> >@           IN    SOA   ns1.xxx.net. hostmaster.xxx.net. (
>> >				1997101001     ; serial
>> >				300            ; refresh
>> >				300            ; retry
>> >				604800         ; expire
>> >				600)           ; minimum
>> >
>> >				IN      NS        ns1.xxx.net.
>> >				IN      NS        ns2.xxx.net.
>> >
>> >
>> >*           IN      PTR     rfc1918.xxx.net.
>> >-----------
>> >
>> >then in named.bt
>> >
>> >primary        16.172.in-addr.arpa       RFC1918.DB
>> >primary        17.172.in-addr.arpa       RFC1918.DB
>> >primary        18.172.in-addr.arpa       RFC1918.DB
>> >primary        19.172.in-addr.arpa       RFC1918.DB
>> >primary        20.172.in-addr.arpa       RFC1918.DB
>> >primary        21.172.in-addr.arpa       RFC1918.DB
>> >primary        22.172.in-addr.arpa       RFC1918.DB
>> >primary        23.172.in-addr.arpa       RFC1918.DB
>> >primary        24.172.in-addr.arpa       RFC1918.DB
>> >primary        25.172.in-addr.arpa       RFC1918.DB
>> >primary        26.172.in-addr.arpa       RFC1918.DB
>> >primary        27.172.in-addr.arpa       RFC1918.DB
>> >primary        28.172.in-addr.arpa       RFC1918.DB
>> >primary        29.172.in-addr.arpa       RFC1918.DB
>> >primary        30.172.in-addr.arpa       RFC1918.DB
>> >primary        31.172.in-addr.arpa       RFC1918.DB
>> >

>> >repeat for 10.x.x.x and 192.168 space
>> >
>> >To reiterate the question posed by the original poster, (donning
asbestos),
>> >why is this bad?
>> >
>> >Eric
>> >
>> >
>> >At 08:31 AM 9/28/98 -0500, you wrote:
>> >>Tatsuya Kawasaki wrote:
>> >>>xyz.com.   IN NS  that.host
>> >>>*.xyz.com  In NS  that.host
>> >>
>> >>Gah!!
>> >>
>> >>Illegal!
>> >>
>> >>Never use "*" in DNS!  Just makes /bad things/ happen.
>> >>
>> >>@	IN	SOA	xyz.com. hostmaster.xyz.com. (
>> >>		1998092801 3600 1800 3600000 7200)
>> >>
>> >>	ns	ns1.xyz.com.
>> >>	ns	ns2.xyz.com.
>> >>
>> >>	mx	0 mail.xyz.com.
>> >>
>> >>mail	a	1.2.3.4
>> >>	mx	0 mail
>> >>
>> >>. etc ..
>> >>
>> >>-- 
>> >>jamie rishaw (efnet:gavroche)               American Information Systems,
>> >Inc.
>> >>                   Tel:312.425.7140, FAX:312.425.7240
>> >>            Help stop spam!  router(config)#no ip routing
>> >>     thirty thousand feet above the earth..youre a beautiful thing.. 
>> >> 
>> >
>> >==========================================================================
>> >  Eric Germann                                        CCTec
>> >  ekgermann@cctec.com                                 Van Wert, OH 45891
>> >  http://www.cctec.com                                Ph: 419 968 2640
>> >                                                      Fax: 419 968 2641
>> >         Network Design, Connectivity & System Integration Services 
>> >                     A Microsoft Solution Provider
>> > 
>> 
>

___________________________________________________ 
Roeland M.J. Meyer, ISOC (InterNIC RM993) 
e-mail: <mailto:rmeyer@mhsc.com>rmeyer@mhsc.com
Internet phone: hawk.mhsc.com
Personal web pages: <http://www.mhsc.com/~rmeyer>www.mhsc.com/~rmeyer
Company web-site: <http://www.mhsc.com/>www.mhsc.com/
___________________________________________ 
I bet the human brain is a kludge.
                -- Marvin Minsky





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