PTR / rDNS
===========

**PTR / rDNS** allows you to explicitly set a custom reverse DNS (rDNS) entry (PTR record)
for your slices.

By default, PTR/rDNS records are automatically set to the hostname you give your slice. 
If your slice is renamed, these are also updated to the new name.  But sometimes, there 
are cases where you want to assign a custom PTR/rDNS to your slice.  

PTR / rDNS table
-----------------

The main table contains the following columns, sorted by *slice name*:

IP Address(es)
  IPv4 and IPv6 addresses, if assigned.

Region
  Region for the addresses.

Slice
  Slice hostname the IP address(es) are assigned to.

PTR/rDNS
  The current PTR/rDNS record(s) for the IP addresses.  If no custom PTR/rDNS has been set,
  this will be identical to the slice name.

Edit
  Click to edit the PTR/rDNS record(s) for the address(es).  A window will appear prompting 
  for the new record.  Click :guilabel:`Update` to update. 

.. Note::
   PTR/rDNS records must match the same criteria as hostnames.  That is, they must not begin or
   end with a "-", and valid characters are: letters, numbers, dash and dot.

.. Hint::
   To check the PTR/rDNS record, query the Syminet nameservers directly using the `dig` or 
   `host` commands.  

Delete
  If a custom record exists, click :guilabel:`Delete` to remove it.  A confirmation dialog 
  box will appear.  Once confirmed, the custom record will be removed and revert back the 
  the hostname for the slice.

.. Note:: 
   If a slice with a custom PTR/rDNS is :doc:`Renamed <../slices/rename>`, there will be 
   a checkbox on the form to also remove any custom record.  Otherwise, the slice will be 
   renamed only.