More than 4k TXT entries

Michael Graff mgraff at isc.org
Wed Feb 29 19:56:15 UTC 2012


Actually, no, there isn't enough information in your reply to help you debug.

Please issue, from a machine not your DNS server:

$ dig @your-server-address +tcp domain.name TXT

A TXT record has a maximum length of around 64k per TXT record, and each part of the text record can be 255 bytes, if memory serves.  However, this is well beyond practical limits.

The size of the zone is not really important compared to the size of the individual TXT record at a specific name.  There is no maximum that spreads across names, but there are practical limits.

If you just have a long string of TXT records, each at its own name like in your example, you should not be running into problems.

--Michael


On Feb 29, 2012, at 1:48 PM, Darvin Denmian wrote:

> Hi,
> 
> Graff, thanks for you reply...
> 
> As you can see below my server is accepting DNS connections:
> 
> ACCEPT     udp  --  anywhere             anywhere            udp dpt:domain
> ACCEPT     tcp  --  anywhere             anywhere            tcp dpt:domain
> 
> and the service is up and running:
> 
> # netstat -ntplu | grep -i named
> tcp        0      0 XXX.XXX.XX.XXX:53           0.0.0.0:*
>     LISTEN      7547/named
> tcp        0      0 XXX.XXX.XX.XXX:53           0.0.0.0:*
>     LISTEN      7547/named
> tcp        0      0 127.0.0.1:953                        0.0.0.0:*
>              LISTEN      7547/named
> udp        0      0 XXX.XXX.XX.XXX:53           0.0.0.0:*
>                 7547/named
> udp        0      0 XXX.XXX.XX.XXX:53           0.0.0.0:*
>                 7547/named
> 
> The zone file is composed of a lot of TXT records...below a small
> piece of the file:
> 
> spf_10000 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_10001 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_10003 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_10004 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_10008 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> ...
> spf_16416 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_16417 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_16418 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_16419 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> spf_16420 900 IN TXT "v=spf1 ip4:XX.XX.XXX.XX/28 ip4:XX.XX.XXX.XX ?all"
> 
> I hope those informations can help you to help me :)
> 
> Regards!
> 
> 
> On Wed, Feb 29, 2012 at 4:25 PM, Michael Graff <mgraff at isc.org> wrote:
>> more than 4k will exceed the default settings for EDNS0 UDP responses.
>> 
>> If you dig @ your server, with +tcp, do you get a reply?  If not, perhaps you are not allowing TCP connections to port 53?
>> 
>> What error you are getting may be of help.
>> 
>> --Michael
>> 
>> On Feb 29, 2012, at 1:20 PM, Darvin Denmian wrote:
>> 
>>> Hi....
>>> 
>>> I would like to know if there is some limitation in Bind regard:
>>> 
>>>    - Max number of TXT entries for a specific domain
>>> or
>>>    - Max size of a zone file
>>> 
>>> I'm asking this because one of the domains configured in my Bind
>>> server have more than 4k TXT entries and its zone file have more than
>>> 400KB.
>>> 
>>> So ....my problem is....
>>> 
>>> When I perform a DNS query , requesting the last TXT entries that I've
>>> added, I receive no answer from my Bind server.
>>> 
>>> Do you have some ideia of what is happening?
>>> 
>>> I hope you can help me and .....understand my Brazilian English :p .
>>> _______________________________________________
>>> Please visit https://lists.isc.org/mailman/listinfo/bind-users to unsubscribe from this list
>>> 
>>> bind-users mailing list
>>> bind-users at lists.isc.org
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>> 




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