1

I try to add DNS record by using DNSPython;

it works well when I set dns like this:

import dns.resolver
import dns.query
import dns.reversename
import dns.update
import dns.rdatatype

update = dns.update.Update('test.com')
update.replace('a', 3600, dns.rdatatype.A, '10.10.10.10')
response = dns.query.tcp(update, '127.0.0.1')

However it doesn't work when I set reverse dns by the same way:

update = dns.update.Update('10.in-addr.arpa')
update.replace('10.10.10.', 3600, dns.rdatatype.PTR, 'a.test.com')
response = dns.query.tcp(update, '127.0.0.1')

I want to know how to set reverse dns successfully, Thx~

Karon
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3 Answers3

1

I find the problem:

update.replace('10.10.10.', 3600, dns.rdatatype.PTR, 'a.test.com')

this should be like this;

update.replace('10.10.10', 3600, dns.rdatatype.PTR, 'a.test.com')

But another problem is: This way to update reverse dns is not always successful, sometimes when I use 'nslookup' to test, it seems that it isn't added to dns server;

what's more, when I nslookup ip like:

nslookup 10.10.10.10
Server:         127.0.0.1
Address:        127.0.0.1#53

10.10.10.10.in-addr.arpa        name =a.test.com.10.in-addr.arpa.

This is not what I want, when using nsupdate to add, it only shows:

10.10.10.10.in-addr.arpa        name =a.test.com.

What can I do to fix this?

Karon
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1

Encountered this issue myself.
You're missing a dot at the end of you name:

update.replace('10.10.10', 3600, dns.rdatatype.PTR, 'a.test.com**.**')
Pang
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Chen Shabi
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-1

You have issue with the '10.10.10' in the update.replace. It needs to be FQDN - '10.10.10.10.in-addr.arpa'. You can use something like this:

Get reverse IP

reventry = dns.reversename.from_address('10.10.10.10')

Define in-addr.arpa zone to update - I have .labels[3:] for A class subnet zone file (10.in-addr.arpa). If you have C class (10.10.10.in-addr.arpa) then use .labels[1:]

revzone = ''
revzone = '.'.join(dns.name.from_text(str(reventry)).labels[3:])

And add the action

raction = dns.update.Update(revzone)
raction.replace(reventry, 3600, dns.rdatatype.PTR, 'a.test.com')

This should work just fine.

balonik
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