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I've been trying to figure out how to set up a reverse zone based on an already existing forward zone, but I keep getting an error saying server can't find xx.xxx.xx.xxx.in-addr.arpa: SERVFAIL whenever I try to run an IP through nslookup. Here's the forward zone in question:

$TTL    15M
@       IN      SOA     ns1.b900.et. root.b900.et. (
                     2019061200         ; Serial
                            15M         ; Refresh
                             5M         ; Retry
                           120M         ; Expire
                            600 )       ; Negative Cache TTL
@              IN      NS      ns1
@              IN      A       164.40.155.48
ns1            IN      A       164.40.155.48
b900           IN      A       164.40.155.48

And here's the reverse zone:

$ORIGIN 42.168.192.in-addr.arpa.
$TTL    15M
@       IN      SOA     ns1.b900.et. root.b900.et. (
                     2019061201         ; Serial
                            15M         ; Refresh
                             5M         ; Retry
                           120M         ; Expire
                            600 )       ; Negative Cache TTL
@       IN      NS      ns1.b900.et.  
48      IN      PTR     ns1.b900.et.

Running named-checkzone doesn't return anything, so I'm wondering what I'm doing wrong.

Al Fney
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    I don’t know whether it’s a general rule, but I find it’s common that reverse DNS is managed by whoever owns “your” IP range. – Mikael H Jun 12 '19 at 10:07
  • @MikaelH true, but here the IP addresses are in the private block of `192.168.0.0/16` (rfc1918 section 3 and rfc6761 section 6.1), so anyone is free to (locally) manage the reverse handling. – Patrick Mevzek Jun 12 '19 at 15:51
  • "what I'm doing wrong. " in all cases like that you need to show **exactly** what you tried, what command you entered. You have shown only part of the response, and redacted. Show real commands and outputs. – Patrick Mevzek Jun 12 '19 at 15:52
  • Your reverse zone (192.168.42.0/24) does not match at all your forward zone, which references `164.40.155.48`. So your question is really not clear. – Patrick Mevzek Jun 12 '19 at 15:53
  • @PatrickMevzek: Correct; I missed that the reverse zone pertained to local addresses. With split DNS there’s nothing preventing you from having a reverse zonefile for internal use, naturally. – Mikael H Jun 12 '19 at 16:31

1 Answers1

2

The reverse lookup zone is managed by the entity that manages that particular netblock, which almost certainly isn't you.

joeqwerty
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