B-Root Statement on Zone Transfers

2026-04-30

b.root-servers.net commits to offer production DNS zone transfers (AXFR) for the root zone.

However, we reserve the right to suspend zone transfers if it interferes with our primary responsibility of service DNS over UDP and TCP.

Zone transfers help support services such as running a local copy of the root as specified in RFC-8806.

Testing it

You can test zone transfers using the ISC bind package’s dig utility:

   $ dig @b.root-servers.net axfr .
   ...
   
   .			86400	IN	SOA	a.root-servers.net. nstld.verisign-grs.com. 2026043002 1800 900 604800 86400
   .			518400	IN	NS	a.root-servers.net.
   .			518400	IN	NS	b.root-servers.net.
   .			518400	IN	NS	c.root-servers.net.
   ...
   ;; SERVER: 2801:1b8:10::b#53(b.root-servers.net) (TCP)
   ...
   ;; XFR size: 24881 records (messages 86, bytes 1422117)
   ...