Re: [gentoo-user] Managing rDNS with BIND

2012-01-14 Thread Carlos Sura
On 8 January 2012 16:02, Alan McKinnon alan.mckin...@gmail.com wrote:

 On Sat, 7 Jan 2012 09:45:44 -0600
 Carlos Sura carlos.su...@googlemail.com wrote:

  Hello mates,
 
  I have a problem, my provider does not want to set rDNS to my IP's
  since I have 5 IP's rotating for my server, I don't know why. So he
  told me I can do this manually.
 
  So I've added this as a master zone:
  $ttl 38400
  80.236.109.in-addr.arpa. IN SOA dominio.dominio.com.
  abuse.dominio.com. (notice that last digits are miss)
  1325905990
  10800
  3600
  604800
  38400 )
  80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 
 
  But it does not reflect any change in any machine, just in the local
  machine I get the answer, when I try in any other machine, it still
  showing me the rDNS of my provider.


 The reason is quite simple and most sane ISPs will do it that way.

 rDNS is NOT your A records in reverse, and you have no right of access
 to the zone.

 in-addr.arpa serves an entirely different purpose, it documents the
 layout of the ISPs address space. Your 5 IPs have not been delegated to
 you and you do not own them per whois, they still belong to your ISP and
 are merely recorded in the ISP record as assigned for your use.

 Therefore the ISP will use their own documentation standards to
 determine what is in the rDNS zone.

 Additionally, delegating out a /29 is a gigantic pain in the arse and
 leads to an unmaintainable mess in very short order (so says the poor
 sucker that's had to fix it...). At work we never sub-delegate out rDNS
 to customers; but we do do it for downstream re-sellers as they are
 ISPs in the in own right.

 So your ISP is quite correct in what they are saying. However, I would
 like to see a clarification of what your support contact means when he
 says do it manually - that doesn't make any sense

 --
 Alan McKinnon



Hello Alan McKinnon,

Thank you for your answer, I get you now you explained everything I needed
to know. About my ISP, they changed it for me, since I was sending a lot of
ticket support to them, because they have a poor support, I understand they
don't manage and help me with a lot of things, basically I don't need them,
the only thing I was asking for is to set the rDNS for me, hopefully they
did, cause I told them, that I really don't understand what they mean by
do it by myself and I was reading all BIND ebook to understad how
delegation works.

Regards

-- 
Carlos Sura.-
www.carlossura.com


Re: [gentoo-user] Managing rDNS with BIND

2012-01-14 Thread Alan McKinnon
On Sat, 14 Jan 2012 13:35:16 -0600
Carlos Sura carlos.su...@googlemail.com wrote:

 On 8 January 2012 16:02, Alan McKinnon alan.mckin...@gmail.com
 wrote:
 
  On Sat, 7 Jan 2012 09:45:44 -0600
  Carlos Sura carlos.su...@googlemail.com wrote:
 
   Hello mates,
  
   I have a problem, my provider does not want to set rDNS to my IP's
   since I have 5 IP's rotating for my server, I don't know why. So
   he told me I can do this manually.
  
   So I've added this as a master zone:
   $ttl 38400
   80.236.109.in-addr.arpa. IN SOA dominio.dominio.com.
   abuse.dominio.com. (notice that last digits are miss)
   1325905990
   10800
   3600
   604800
   38400 )
   80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  
  
   But it does not reflect any change in any machine, just in the
   local machine I get the answer, when I try in any other machine,
   it still showing me the rDNS of my provider.
 
 
  The reason is quite simple and most sane ISPs will do it that way.
 
  rDNS is NOT your A records in reverse, and you have no right of
  access to the zone.
 
  in-addr.arpa serves an entirely different purpose, it documents the
  layout of the ISPs address space. Your 5 IPs have not been
  delegated to you and you do not own them per whois, they still
  belong to your ISP and are merely recorded in the ISP record as
  assigned for your use.
 
  Therefore the ISP will use their own documentation standards to
  determine what is in the rDNS zone.
 
  Additionally, delegating out a /29 is a gigantic pain in the arse
  and leads to an unmaintainable mess in very short order (so says
  the poor sucker that's had to fix it...). At work we never
  sub-delegate out rDNS to customers; but we do do it for downstream
  re-sellers as they are ISPs in the in own right.
 
  So your ISP is quite correct in what they are saying. However, I
  would like to see a clarification of what your support contact
  means when he says do it manually - that doesn't make any sense
 
  --
  Alan McKinnon
 
 
 
 Hello Alan McKinnon,
 
 Thank you for your answer, I get you now you explained everything I
 needed to know. About my ISP, they changed it for me, since I was
 sending a lot of ticket support to them, because they have a poor
 support, I understand they don't manage and help me with a lot of
 things, basically I don't need them, the only thing I was asking for
 is to set the rDNS for me, hopefully they did, cause I told them,
 that I really don't understand what they mean by do it by myself
 and I was reading all BIND ebook to understad how delegation works.
 
 Regards
 

Hi Carlos,

I'm glad to hear you came right.

Yes, having your ISP update their rDNS with your machine's name is the
best solution all round.


-- 
Alan McKinnnon
alan.mckin...@gmail.com




Re: [gentoo-user] Managing rDNS with BIND

2012-01-08 Thread Alan McKinnon
On Sat, 7 Jan 2012 09:45:44 -0600
Carlos Sura carlos.su...@googlemail.com wrote:

 Hello mates,
 
 I have a problem, my provider does not want to set rDNS to my IP's
 since I have 5 IP's rotating for my server, I don't know why. So he
 told me I can do this manually.
 
 So I've added this as a master zone:
 $ttl 38400
 80.236.109.in-addr.arpa. IN SOA dominio.dominio.com.
 abuse.dominio.com. (notice that last digits are miss)
 1325905990
 10800
 3600
 604800
 38400 )
 80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 
 
 But it does not reflect any change in any machine, just in the local
 machine I get the answer, when I try in any other machine, it still
 showing me the rDNS of my provider.


The reason is quite simple and most sane ISPs will do it that way.

rDNS is NOT your A records in reverse, and you have no right of access
to the zone.

in-addr.arpa serves an entirely different purpose, it documents the
layout of the ISPs address space. Your 5 IPs have not been delegated to
you and you do not own them per whois, they still belong to your ISP and
are merely recorded in the ISP record as assigned for your use.

Therefore the ISP will use their own documentation standards to
determine what is in the rDNS zone.

Additionally, delegating out a /29 is a gigantic pain in the arse and
leads to an unmaintainable mess in very short order (so says the poor
sucker that's had to fix it...). At work we never sub-delegate out rDNS
to customers; but we do do it for downstream re-sellers as they are
ISPs in the in own right.

So your ISP is quite correct in what they are saying. However, I would
like to see a clarification of what your support contact means when he
says do it manually - that doesn't make any sense

-- 
Alan McKinnon



Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Duane Hill
On Saturday, January 07, 2012 at 15:45:44 UTC, carlos.su...@googlemail.com 
confabulated:

 Hello mates,

 I have a problem, my provider does not want to set rDNS to my IP's since I
 have 5 IP's rotating for my server, I don't know why. So he told me I can
 do this manually.

 So I've added this as a master zone:
 $ttl 38400
 80.236.109.in-addr.arpa. IN SOA dominio.dominio.com. abuse.dominio.com.
 (notice that last digits are miss)
 1325905990
 10800
 3600
 604800
 38400 )
 80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
 xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.


 But it does not reflect any change in any machine, just in the local
 machine I get the answer, when I try in any other machine, it still showing
 me the rDNS of my provider.

 Any help?

The  setting  up  rDNS  on  the one server would only be for that local
server.   All   other  servers that are not using the one local server
for  DNS resolution would look to your provider. You would either have
to 1) get your provider to delegate rDNS to you, 2) duplicate the rDNS
setup   on  the  additional  servers, or 3) point DNS (resolv.conf) to
the one server that is working locally.

Without   your   provider   delegating   rDNS to you, the rest of the
world would still be looking to your provider for rDNS, regardless.

-- 
If at first you don't succeed...
...so much for skydiving.




Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Carlos Sura
On 7 January 2012 10:08, Duane Hill duih...@gmail.com wrote:

 On Saturday, January 07, 2012 at 15:45:44 UTC, 
 carlos.sura1@googlemail.comconfabulated:

  Hello mates,

  I have a problem, my provider does not want to set rDNS to my IP's since
 I
  have 5 IP's rotating for my server, I don't know why. So he told me I can
  do this manually.

  So I've added this as a master zone:
  $ttl 38400
  80.236.109.in-addr.arpa. IN SOA dominio.dominio.com. abuse.dominio.com.
  (notice that last digits are miss)
  1325905990
  10800
  3600
  604800
  38400 )
  80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.


  But it does not reflect any change in any machine, just in the local
  machine I get the answer, when I try in any other machine, it still
 showing
  me the rDNS of my provider.

  Any help?

 The  setting  up  rDNS  on  the one server would only be for that local
 server.   All   other  servers that are not using the one local server
 for  DNS resolution would look to your provider. You would either have
 to 1) get your provider to delegate rDNS to you, 2) duplicate the rDNS
 setup   on  the  additional  servers, or 3) point DNS (resolv.conf) to
 the one server that is working locally.

 Without   your   provider   delegating   rDNS to you, the rest of the
 world would still be looking to your provider for rDNS, regardless.

 --
 If at first you don't succeed...
 ...so much for skydiving.



Hello Duane,

Thank your for answer. I just have one question: What you mean that my
provider has to delegate rDNS to me? I have the resolv.conf with my own
nameservers.

Locally it shows as I want, but not on the Internet. What would I need to
ask to my provider?

Thanks!


-- 
Carlos Sura.-
www.carlossura.com


Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Duane Hill
On Saturday, January 07, 2012 at 16:15:47 UTC, carlos.su...@googlemail.com 
confabulated:

 On 7 January 2012 10:08, Duane Hill duih...@gmail.com wrote:

 On Saturday, January 07, 2012 at 15:45:44 UTC, 
 carlos.sura1@googlemail.comconfabulated:

  Hello mates,

  I have a problem, my provider does not want to set rDNS to my IP's since
 I
  have 5 IP's rotating for my server, I don't know why. So he told me I can
  do this manually.

  So I've added this as a master zone:
  $ttl 38400
  80.236.109.in-addr.arpa. IN SOA dominio.dominio.com. abuse.dominio.com.
  (notice that last digits are miss)
  1325905990
  10800
  3600
  604800
  38400 )
  80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
  xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.


  But it does not reflect any change in any machine, just in the local
  machine I get the answer, when I try in any other machine, it still
 showing
  me the rDNS of my provider.

  Any help?

 The  setting  up  rDNS  on  the one server would only be for that local
 server.   All   other  servers that are not using the one local server
 for  DNS resolution would look to your provider. You would either have
 to 1) get your provider to delegate rDNS to you, 2) duplicate the rDNS
 setup   on  the  additional  servers, or 3) point DNS (resolv.conf) to
 the one server that is working locally.

 Without   your   provider   delegating   rDNS to you, the rest of the
 world would still be looking to your provider for rDNS, regardless.

 --
 If at first you don't succeed...
 ...so much for skydiving.



 Hello Duane,

 Thank your for answer. I just have one question: What you mean that my
 provider has to delegate rDNS to me? I have the resolv.conf with my own
 nameservers.

 Locally it shows as I want, but not on the Internet. What would I need to
 ask to my provider?

 Thanks!

You  would  have  to find out if your provider would delegate rDNS for
the  IP  address range to you. You would have to provide them with the
name server IP addresses that would be serving rDNS. I can only assume
if  they  will not set up the rDNS for you, they may not delegate rDNS
either.

If you are trying to set up an email server and your provider will not
delegate  or  set  up the rDNS, just set up your email server to relay
outbound  messages  through  your  provider. That is exactly what I am
doing here and have been for 5+ years without any issues.

-- 
If at first you don't succeed...
...so much for skydiving.




Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Michael Hampicke
 Thank your for answer. I just have one question: What you mean that my
 provider has to delegate rDNS to me? I have the resolv.conf with my own
 nameservers.
 
 Locally it shows as I want, but not on the Internet. What would I need to
 ask to my provider?

You have to set the rdns entries on the 'authoritative name server' of
your domain (it's the nameserver that manages your domain).



Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Carlos Sura
On 7 January 2012 10:28, Duane Hill duih...@gmail.com wrote:

 On Saturday, January 07, 2012 at 16:15:47 UTC, 
 carlos.sura1@googlemail.comconfabulated:

  On 7 January 2012 10:08, Duane Hill duih...@gmail.com wrote:

  On Saturday, January 07, 2012 at 15:45:44 UTC,
 carlos.sura1@googlemail.comconfabulated:
 
   Hello mates,
 
   I have a problem, my provider does not want to set rDNS to my IP's
 since
  I
   have 5 IP's rotating for my server, I don't know why. So he told me I
 can
   do this manually.
 
   So I've added this as a master zone:
   $ttl 38400
   80.236.109.in-addr.arpa. IN SOA dominio.dominio.com.
 abuse.dominio.com.
   (notice that last digits are miss)
   1325905990
   10800
   3600
   604800
   38400 )
   80.236.109.in-addr.arpa. IN NS dominio.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns1.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR ns2.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR dominio.com.
   xx.xx.xxx.xxx.in-addr.arpa. IN PTR mail.dominio.com.
 
 
   But it does not reflect any change in any machine, just in the local
   machine I get the answer, when I try in any other machine, it still
  showing
   me the rDNS of my provider.
 
   Any help?
 
  The  setting  up  rDNS  on  the one server would only be for that local
  server.   All   other  servers that are not using the one local server
  for  DNS resolution would look to your provider. You would either have
  to 1) get your provider to delegate rDNS to you, 2) duplicate the rDNS
  setup   on  the  additional  servers, or 3) point DNS (resolv.conf) to
  the one server that is working locally.
 
  Without   your   provider   delegating   rDNS to you, the rest of the
  world would still be looking to your provider for rDNS, regardless.
 
  --
  If at first you don't succeed...
  ...so much for skydiving.
 
 
 
  Hello Duane,

  Thank your for answer. I just have one question: What you mean that my
  provider has to delegate rDNS to me? I have the resolv.conf with my own
  nameservers.

  Locally it shows as I want, but not on the Internet. What would I need to
  ask to my provider?

  Thanks!

 You  would  have  to find out if your provider would delegate rDNS for
 the  IP  address range to you. You would have to provide them with the
 name server IP addresses that would be serving rDNS. I can only assume
 if  they  will not set up the rDNS for you, they may not delegate rDNS
 either.

 If you are trying to set up an email server and your provider will not
 delegate  or  set  up the rDNS, just set up your email server to relay
 outbound  messages  through  your  provider. That is exactly what I am
 doing here and have been for 5+ years without any issues.

 --
 If at first you don't succeed...
 ...so much for skydiving.



This is quite interesting. Yes, what I'm trying to set up is a email
server. But I'm not sure how to set that configuration, can you send me a
link or resource? because I'm having emails issue because rDNS.

In any case, I will do a research.

Thanks.

-- 
Carlos Sura.-
www.carlossura.com


Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Carlos Sura
On 7 January 2012 10:30, Michael Hampicke gentoo-u...@hadt.biz wrote:

  Thank your for answer. I just have one question: What you mean that my
  provider has to delegate rDNS to me? I have the resolv.conf with my own
  nameservers.
 
  Locally it shows as I want, but not on the Internet. What would I need to
  ask to my provider?

 You have to set the rdns entries on the 'authoritative name server' of
 your domain (it's the nameserver that manages your domain).


Well, I think I did, but it only works or shows that it's working on the
same machine. In any other machine, rDNS not working it shows my provider's
configuration.

-- 
Carlos Sura.-
www.carlossura.com


Re: [gentoo-user] Managing rDNS with BIND

2012-01-07 Thread Duane Hill
On Saturday, January 07, 2012 at 16:30:47 UTC, gentoo-u...@hadt.biz 
confabulated:

 Thank your for answer. I just have one question: What you mean that my
 provider has to delegate rDNS to me? I have the resolv.conf with my own
 nameservers.
 
 Locally it shows as I want, but not on the Internet. What would I need to
 ask to my provider?

 You have to set the rdns entries on the 'authoritative name server' of
 your domain (it's the nameserver that manages your domain).

Not  necessarily.  The  two are completely separate zone files. Having
authority  to  provide DNS for a domain name to the Internet just sets
up the forward lookup (not the reverse IP).

For reverse  DNS you either 1) have to have been directly allocated the IP
space,  2)  been  delegated  rDNS from the upstream IP provider, or 3)
have the upstream IP provider set up the rDNS for you.

-- 
If at first you don't succeed...
...so much for skydiving.