Manage PTR Records

Overview 
 PTR  (pointer) is reverse DNS: the name the internet sees when something looks up your  public IPv4  address. Many mail servers and some services expect your PTR to look professional (often a  fully qualified domain name , or FQDN, such as  mail.example.com ). 
 For mail and reputation, it is best practice that  PTR and forward DNS agree : the IP’s PTR should point at a hostname that, in turn,  resolves forward (A record) back to the same IP . If they do not match, some recipients may defer or reject mail or treat the host as less trustworthy. 
 You manage PTR in the NOC portal on  IP Address Management  for addresses  on your account . You cannot set PTR for IPs you do not own through this page. 
 Before you change anything 
 
 Decide on the hostname  you want (an FQDN you control). 
 Create/update forward DNS so that the hostname’s  A record  points to  this same IPv4 . Do this in your DNS hosting (zone for the domain), not only in the portal. 
 Wait for DNS to propagate  if you just created the record (often minutes, sometimes longer). 
 In the portal, open  IP Address Management , find the IP (search, service filter, or  Ctrl+K ), and expand the row or use  Update reverse DNS where offered. 
 
 Set a custom PTR (single address) 
 
 Open the IP’s  PTR flow (expanded row,  Save  after editing the PTR field, or the  Reverse DNS  modal). 
 Enter the  new PTR  as a valid  FQDN  (e.g.  smtp.example.com ). Do not use bare words like  mail  without a domain; the portal expects a proper hostname format. 
 Confirm the value matches what you want the world to see  and  that your  forward DNS (A)  for that name already points to this IP. 
 Click  Apply PTR  /  Save . The portal sends the change to the API; the upstream API system may normalise the name slightly (e.g. trailing dot). 
 After a few minutes, verify with an external tool (reverse lookup on the IP) or  dig -x YOUR.IP from your own machine. 
 
 
 Reset PTR to the default 
 
 Open the same IP in  IP Address Management . 
 Use default  (modal) or  Reset  (expanded row), depending on which UI you are in. 
 Confirm the action. The PTR returns to the platform  default  for that service/IP. 
 Allow a short time for the change to appear globally, then verify with a reverse DNS lookup if needed. 
 
 Use this when you no longer host mail on that IP, you used a temporary hostname, or a custom PTR is causing mismatch warnings. 
 Bulk PTR updates 
 If you must align many addresses at once (e.g. after a migration), open  Bulk PTR update , paste one  IP and hostname  per line (separated by space, tab, or comma), and review the counts for  valid ,  invalid , and  not yours  before queuing. Only lines for  your IPs are applied. The maximum batch size is  500 per run; large jobs are completed in a queue with a summary at the end. 
 
 Troubleshooting 
 
 
 
 
 
 
 Issue 
 What to check 
 
 
 
 
 
 Save rejected or “invalid” hostname 
 
 
 Use a real FQDN; check length and characters (letters, numbers, dots, hyphens per DNS rules). 
 
 
 
 
 Mail still failing PTR checks 
 
 
 Confirm that a record for the PTR name points to  this  IP; wait for DNS TTL/propagation. 
 
 
 
 
 Wrong IP / no permission 
 
 
 PTR can only be set for IPs listed under your account on this page. 
 
 
 
 
 Change is slow to show 
 
 
 Global DNS caches can delay what you see; wait and test again with a fresh lookup. 
 
 
 
 
 
 
 
 Quick checklist 
 
  Forward  A  (or appropriate record) points hostname →  this IPv4 
 PTR in the portal is set to that same hostname  (FQDN) 
 Verified with an external reverse lookup after propagation