DNS Lookup

I have not yet used the NAME:: commands, but I did find this code: (Click here which seems to use slightly different syntax for the NAME::response command.

 

 

HTH

 

/deb

You also need to be sure that you've tweaked your configs appropriately, as is noted in the CodeShare page deb linked to in the above post. Use the syntax listed there along with the conf changes need, and you should be all set.

 

 

Colin

Is this configuration still required on v9.4? I tried this and am get a blank response as well.

I'm just doing a brute force test to see if resolution is working. I assume this can be host to IP.

 
 when HTTP_REQUEST  priority 5 { 
     Hold HTTP data until hostname is resolved 
    HTTP::collect 
   
     Start a name resolution on the hostname 
    NAME::lookup "www.xmission.com" 
 } 
 when NAME_RESOLVED { 
    log local0. "client name = >[NAME::response]<" 
   
     Release HTTP data once hostname is resolved 
    HTTP::release 
 } 
 

Thanks,

Tom Schaefer

Hi,

 

 

One question. When doing the NAME::lookup, i understand it will send a name resolution petition to a DNS. My question is where to configure the DNS where the petitions will be sent. Can it be specified in the command, or it must be done in other configuration??

 

 

Thank you very much.

 

 

BR

hi Adrian,

 

 

For 9.4.2+ you can use the steps in SOL8437:

 

 

SOL8437: Configuring BIG-IP to resolve DNS hostnames

 

https://support.f5.com/kb/en-us/solutions/public/8000/400/sol8437.html

 

 

For older versions, you can check SOL3624:

 

 

SOL3624: Configuring DNS name resolution

 

https://support.f5.com/kb/en-us/solutions/public/3000/600/sol3624.html

 

 

And here are a few examples of using NAME::lookup and validating the response:

 

 

http://devcentral.f5.com/wiki/default.aspx/iRules/DestinationSnatUsingDNS.html

 

 

http://devcentral.f5.com/Default.aspx?tabid=53&forumid=31&tpage=1&view=topic&postid=8551885545

 

 

SOL5299: The BIG-IP system does not forward DNS requests after configuring the BIND Forwarder Server List

 

https://support.f5.com/kb/en-us/solutions/public/5000/200/sol5299.html

 

 

Aaron

With NAME::lookup, the event NAME_RESOLVED fires when the resolution occurs and you use NAME::response to retrieve it. New in 10.1 is the RESOLV::lookup command, which suspends and returns the results inline.

ha! Yeah, I do need to get that documentation cranked out. I've also wondered as commands are added...why? That would be a good feature to add in the wiki entries. I'll dig and see what I can come up with.

There are several more commands I need to "voluntarily" get out there as well.

Posted By hoolio on 01/19/2010 7:26 AM

 

 

Out of curiosity, why was this change done? Is the idea that you don't use the NAME_RESOLVED event in v10.1, but just call NAME::lookup (or RESOLV(E?)::lookup to resolve the name and get the return in the original event?

 

 

Thanks,

 

Aaron

 

 

 

We now have the capability to suspend execution until we get an asynchronous response, so we are moving commands in that direction. Any new commands that have an asynchronous response will now always be inline.

Thanks for the info. Currently with NAME::lookup does all TMM processing wait until NAME_RESOLVED is triggered? With RESOLV::lookup, is that different?

 

 

Aaron