ZoneRunnner and Wide IP - DNS RESOLUTION.

[EIT_Network]

Hi Experts,

How ZoneRunner feature is different with GTM -> Wide IP.

As both are acting as authoritative DNS and resolving , Is GTM (between two geolocations) need to be confgure for ZoneRunner Or it can work with LTM also (Single Site).

Beleive, i can make F5 BIG-IP to resolve DNS query via WIDE IP without configuring anything under ZONERUNNER.  

Requesting if anyone help to under these two with practical example.

Regards

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[Leonardo_Souza]

In GTM (or new name DNS), you can answer DNS queries dynamically or statically.

Dynamic is using the wide IPs, while statically is using BIND.

ZoneRunner is just a front end for BIND.

When using the GTM (wide IPs), the system will take decisions based on how you setup the wide IPs and GTM pools.

Also, as an example if using LTM, it will check that the virtual server is UP, if not, it will not send response with that virtual server IP.

When answering via BIND, that is static, independent of the virtual server status it will send the virtual server IP.

Wide IP supports a limited number of resources types (like A,AAAA, etc...), while BIND supports almost all types in use (if not all).

So, you may be in a situation that you can't use wide IPs for the resource type you need to setup, so you need to use BIND.

The system will also by default try resolve the name via wide IP, if not possible, it will use BIND.

That is configured in the DNS profile setting "Use BIND Server on BIG-IP", also in the GTM pool setting "Return to DNS".

One important troubleshoot information, GTM (wide IP) answer normally has a TTL very small, as you want the client to come back so you can check if the server still UP.

BIND on the other hand, as it does not care about status, has a larger TTL, just to allow changes of IPs for example.

So, when query a name, you can guess if is GTM (wide IP) answering or BIND based on the TTL value.

GTM default is 30 seconds, BIND TTL default in GTM is 500 seconds, normally is larger in other systems.

[EIT_Network]

Hi Leonardo,

Thanks for prompt response, So can i take this as both GTM(Wide IP) and ZoneRunner are indenpendent of each other and don't have dependency on each other in any manner.

If I understand you correctly, ZoneRunner is just like a traditional DNS server like we have in most of the Data center infrastructure........ Whereas GTM Wide IP is intelligent DNS and behaves as per configuration (like "member ratio") and must require Listener IPs to work. (Listener IP not require for ZoneRunner to Work)

Is my understanding correct....

[Leonardo_Souza]

They do have some dependency, as when you create a wide IP, the system will add a zone and resource records automatically in BIND.

The other way around is not true, as zones or resource groups created in BIND, editing BIND files manually or via ZoneRunner, will not create any configuration related to wide IPs.

As I explained, ZoneRunner is just a front end for BIND, so BIND is the one that processes traffic.

If you change the word ZoneRunner to BIND in your text, yes, it is the traditional DNS server.

BIND will use the same listener IP as GTM (wide IP).

The listener in this context is just like an IP in a server, the server needs an IP to receive traffic, and that is what the listener is for, to receive DNS traffic, either to GTM (wide IP) or BIND.

[EIT_Network]

Hi Leonardo and All,

However i get reply from Leonardo on my Zonerunner Query. But still ..i looking for why ZoneRunner is require, what is the concept of Zonerunner ..if we already having GTM there.

Can anyone help me to understand with some practical use case example or share document.

Rgds

[JRahm]

GTM has some dependencies on the underlying BIND system that is fronted by the Zonerunner utility, which as Leonardo has stated is just a GUI wrapper for BIND. BIND has no dependencies on GTM.

If I have no wideIPs defined, and I have not chosen to use the local BIND instance for anything, then Zonerunner should be completely empty. But let's suppose I add a single wideIP called www.test.local to the GTM config, with a single pool and a single virtual server in that pool with an IP address/port of 10.0.0.101:80.

When that is done, a zone is created in BIND for test.local in the file /var/named/config/namedb/db.external.test.local. with these contents:

[root@ltm3:Active:Standalone] config # cat /var/named/config/namedb/db.external.test.local.
test.local. 500 IN SOA ltm3.test.local. hostmaster.ltm3.test.local. 1 10800 3600 604800 60
test.local. 0 IN NS ltm3.test.local.
ltm3.test.local. 0 IN A 127.0.0.1
www.test.local. 0 IN A 10.0.0.101

And zonerunner will display this zone file like this:

For the details on how the listener processes queries based on the different GTM features you have enabled, see knowledge article 14510.

[GeorgeC]

Is the feature of adding Zonerunner records when creating WideIPs version dependent? I have several domains that do not include the WideIPs in ZOneRunner. The WideIPs appear to be functioning properly (they have been in place for 9 months now). I am using version 13.1.3.4

[JRahm]

It is my understanding that the expected behavior is zones/records are created as a result of the wideIP object creation. If this is not what you are experiencing on a particular version of TMOS, then I'd open a support case for clarification. If my understanding is incorrect, please post back here what you learn. Thanks,  

[GeorgeC]

After I posed the question, I found this bug - https://cdn.f5.com/product/bugtracker/ID613823.html

Which indicates they are aware of the situation. As it says in the bug report, the draw back is if GTM is down and Bind is not, then it will not return an IP. But if GTM is down, we got a bigger problem (at least here we do). So we will manually add the records over time.

Thank you for your quick response.  

[JRahm]

I keep forgetting to reference the bug database! Good find, and thanks for posting back for the benefit of the community!

[EIT_Network]

ok, So once we create Wide-IP in GTM ...... configuration get automatically mimic into ZoneRunner - record Resource list ..... Is'nt It ?

[JRahm]

yes, but again, ZoneRunner is just a front end manager and visual tool for the BIND process on the BIG-IP.