ltm rule command DNS edns0

iRule(1)		      BIG-IP TMSH Manual		      iRule(1)



DNS::edns0
       Gets (v11.0+) and sets (v11.1+) the values of the edns0 pseudo-RR.

SYNOPSIS
       DNS::edns0 'remove' ('nsid' | 'subnet')?

       DNS::edns0 'exists' ('nsid' | 'subnet')?

       DNS::edns0 'do' (BOOLEAN)?

       DNS::edns0 'sz' (UNSIGNED_SHORT)?

       DNS::edns0 'nsid' (BYTE_ARRAY)?

       DNS::edns0 'subnet' (('address' (IP_ADDR)? )	     |
				    ('source'  (DNS_EDNS0_SOURCE)? ) |
				    ('scope'   (DNS_EDNS0_SCOPE)? )
				   )

DESCRIPTION
       This iRules command gets (v11.0+) and sets (v11.1+) the values of the
       edns0 pseudo-RR.

       Note: This command requires the DNS Profile, which is only enabled as
       part of GTM or the DNS Services add-on.

       Syntax

       DNS::edns0 remove []

	    * Removes the entire EDNS0 psuedo-RR or just the nsid or subnet section, if specified.

       DNS::edns0 exists []

	    * Returns boolean for the presense of the EDNS0 psuedo-RR in the
	      current DNS packet. Specifying nsid or subnet returns a
	      boolean for the presense of the NSID or subnet option
	      respectively in the EDNS0 rdata.

	DNS::edns0  [value]

	    * Returns or sets the values of the edns0 pseudo-RR.
		 + do (DNSSEC)
		      o returns boolean of false if no edns0 RR, boolean for
			presence of DO flag, or integer for the UDP size
		 + sz (UDP Max Payload Size)
		      o returns boolean of false if no edns0 RR, boolean for
			presence of DO flag, or integer for the UDP size
		 + nsid (Nameserver ID, RFC 5001)
		      o returns a byte array: empty if an NSID query, non-empty
			containing NSID bytes

	      TCL_ERROR is returned if the command is called when there is
	      no edns0 or NSID field.

       DNS::edns0 subnet [] [value]
	    * v11.5+
	    * Returns or sets IP address, source or scope as specified by the
       argument
	      from the client-subnet option. Without an argument, returns an
       IP
	      address, Integer, and Integer, respectively for IP address,
       source,
	      and scope.

RETURN VALUE
VALID DURING
       DNS_REQUEST, DNS_RESPONSE, GLOBAL_GTM

EXAMPLES
	when DNS_REQUEST {
	  if { [DNS::edns0 exists] } {
	    log local0. [DNS::edns0 subnet address]"
	  }
	}

HINTS
SEE ALSO
CHANGE LOG
       @BIGIP-11.0.0 --First introduced the command.



BIG-IP				  2017-01-31			      iRule(1)