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Caio_178191's avatar
Caio_178191
Icon for Nimbostratus rankNimbostratus
Aug 17, 2015

GTM issue - connection refused

Hi.

 

I'm working with GTM v11.5.2 HF1. I'm having a strange problem that I would like to know your coments about it.

 

The topology is:

 

Workstation->GTM->Link Controler->DNS Server (Authoritative)

 

If I make a DNS query from workstation direct to the Link Controler, it return the ip address as I expect.

 

If I make a DNS query from workstation to the GTM, it's give me query refused.

 

How the GTM is configured?

 

I create a forward zone (teste.com) with link controler ip address. The recursion is on in named configuration, also Set recursion is enable in GTM settings.

 

If I make the query from shell in GTM (using listener ip address), the query return the IP address and I can see communication between gtm and link controller using tcpdump.

 

If I make the query from workstation in GTM (using listener ip address) it's give me QUERY REFUSED and I CAN'T see communication between gtm and link controller using tcpdump. I also did a tcpdump between workstation and GTM, GTM refuse the query without check Link Controller.

 

Please, help. Any comments ? tips?? have u seend it before ?

 

Regards.

 

application delivery
availability
BIG-IP DNS
performance
TMOS
TMSH

3 Replies

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  • Caio_178191's avatar
    Caio_178191
    Icon for Nimbostratus rankNimbostratus
    Aug 20, 2015

    Problem solved.

     

    You must put an ACL in named configuration.

     

    Here we have a default Named Configuration in GTM with recursive deactivated.

     

    Code
restrict rndc access to local machines
use the key in the default place: /config/rndc.key

controls {
    inet 127.0.0.1 port 953 allow {
        127.0.0.1;
    };
};

logging {
    channel logfile {
        syslog daemon;
        severity error;
        print-category yes;
        print-severity yes;
        print-time yes;
    };
    category default {
        logfile;
    };
    category config {
        logfile;
    };
    category notify {
        logfile;
    };
};

options {
    listen-on port 53 {
        127.0.0.1;
        "zrd-acl-000-000";
    };
    listen-on-v6 port 53 {
        ::1;
    };
    recursion no;
    directory "/config/namedb";
    allow-transfer {
        localhost;
    };
    check-names master warn;

    check-integrity yes;
    max-journal-size 1M;
    version "none";
};

acl "zrd-acl-000-000" {
 127.10.0.0;
};

Code

    To activate the recursion, we should change the "no" to "yes" in the line "recursion no". But besides that, we need to add an acl. So, our code will be:

     

    Code
restrict rndc access to local machines
use the key in the default place: /config/rndc.key

controls {
    inet 127.0.0.1 port 953 allow {
        127.0.0.1;
    };
};

logging {
    channel logfile {
        syslog daemon;
        severity error;
        print-category yes;
        print-severity yes;
        print-time yes;
    };
    category default {
        logfile;
    };
    category config {
        logfile;
    };
    category notify {
        logfile;
    };
};

options {
    listen-on port 53 {
        127.0.0.1;
        "zrd-acl-000-000";
    };
    listen-on-v6 port 53 {
        ::1;
    };
    recursion yes;
    directory "/config/namedb";
    allow-transfer {
        localhost;
    };
    check-names master warn;

    check-integrity yes;
    max-journal-size 1M;
    version "none";
    allow-recursion {
      internal;
    };
};

acl "zrd-acl-000-000" {
 127.10.0.0;
};
acl "internal" {
  0.0.0.0/0;
};

Code

    After this configuration, the system starts to accept recursive querys.

     

  • ______54573's avatar
    ______54573
    Icon for Nimbostratus rankNimbostratus
    Jul 25, 2016

    when we recursion yes; and set acl.sometimes GTM will response with source ip 127.0.0.1 to client:10233.748891740127.0.0.110.198.105.41DNS84Standard query response 0x3fb7 Server failure .do you know ?

     

    • boneyard's avatar
      boneyard
      Icon for MVP rankMVP
      Jul 25, 2016

      i would start a new thread and add some info, for example packet capture or dig output.