Good Day,
I'm looking for some help in setting up my zone record correctly for a delegated in-addr.arpa zone (classless reverse DNS) (*names and IPs have been changed).
I have the following net-block assigned to my service, 71.26.226.88/29 and I've asked Comcast to please delegate the Reverse DNS so I can manage the PTR records. To the best of my knowledge Comcast has properly setup their side (the CNAMEs for each entry)
Now, all I have to figure out is how to get my side (BIND9) configured correctly.
You can see from the dig output, something is really wrong since I keep seeing server fail messages. The DNS server is 192.168.15.10 internally, and externally is 71.26.226.90.
**I edited this post to change the domain names and IP address to their real values. It was pointed out to me that I did a poor job obfuscating these details and DNS / IP addresses are all public so it's silly to obfuscate the details.
Here is what I have:
---------------------------------------------
$ORIGIN 88/29.226.26.71.in-addr.arpa.
$TTL 86400
88/29.226.26.71.in-addr.arpa. IN SOA ns.nfvlab.net. admin.nfvlab.net. (
2023041115
43200
180
1209600
10800
)
@ IN NS ns.nfvlab.net.
89 3600 IN PTR gateway.nfvlab.net.
90 3600 IN PTR mail.nfvlab.net.
91 3600 IN PTR 91.nfvlab.net.
92 3600 IN PTR 92.nfvlab.net.
93 3600 IN PTR 93.nfvlab.net.
94 3600 IN PTR 94.nfvlab.net.
---------------------------------------------
named.conf
---------------------------------------------
zone "88/29.226.26.71.in-addr.arpa" {
type slave;
file "/etc/zone/master/88-29.226.26.71.in-addr.arpa";
allow-transfer {none;};
allow-query {any;};
masters {
71.26.226.90;
};
};
---------------------------------------------
helix@Studio ~ % dig @192.168.15.10 88/29.226.26.71.in-addr.arpa PTR
---------------------------------------------
; <<>> DiG 9.10.6 <<>> @192.168.15.10 88/29.226.26.71.in-addr.arpa PTR
; (1 server found)
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: SERVFAIL, id: 36740
;; flags: qr rd ra; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 1232
; OPT=15: 00 16 61 74 20 64 65 6c 65 67 61 74 69 6f 6e 20 38 38 2f 32 39 2e 32 32 36 2e 32 36 2e 37 31 2e 69 6e 2d 61 64 64 72 2e 61 72 70 61 2e ("..at delegation 88/29.226.26.71.in-addr.arpa.")
; OPT=15: 00 17 37 31 2e 32 36 2e 32 32 36 2e 39 30 3a 35 33 20 72 63 6f 64 65 3d 53 45 52 56 46 41 49 4c 20 66 6f 72 20 38 38 2f 32 39 2e 32 32 36 2e 32 36 2e 37 31 2e 69 6e 2d 61 64 64 72 2e 61 72 70 61 20 50 54 52 ("..71.26.226.90:53 rcode=SERVFAIL for 88/29.226.26.71.in-addr.arpa PTR")
;; QUESTION SECTION:
;88/29.226.26.71.in-addr.arpa. IN PTR
;; Query time: 194 msec
;; SERVER: 192.168.15.10#53(192.168.15.10)
;; WHEN: Wed Apr 12 13:48:56 EDT 2023
;; MSG SIZE rcvd: 179
---------------------------------------------
If I send a query from outside like this:
ubuntu@ip-172-37-76-122:~$ host 71.26.226.90
Host 90.226.26.71.in-addr.arpa not found: 2(SERVFAIL)
And this is the output on the Server from tcpdump while doing a query.
14:22:26.293797 IP ec2-3-228-170-37.compute-1.amazonaws.com.26341 > 192.168.15.10.domain: 54423% [1au] PTR? 89.88/29.226.26.71.in-addr.arpa. (60)
14:22:26.293861 IP 192.168.15.10.domain > ec2-3-228-170-37.compute-1.amazonaws.com.26341: 54423 ServFail 0/0/1 (60)
This is what Comcast gave me in terms of instructions:
Instruct customer to create zone (88/29.226.26.71.in-addr.arpa.) with following DNS records (template)
@ IN SOA ns.domain.net. hostmaster.nfvlab.net. 2023041101 7200 3600 604800 3600
88/29 IN NS ns.nfvlab.net.
89 3600 IN PTR 89-nfvlab.net.
90 3600 IN PTR 90-nfvlab.net.
91 3600 IN PTR 91-nfvlab.net.
92 3600 IN PTR 92-nfvlab.net.
93 3600 IN PTR 93-nfvlab.net.
94 3600 IN PTR 94-nfvlab.net.
Any help or pointers (ha ha punny) would be greatly appreciated
