NDB/DNS ndb/dns(8) can provide an authoritative name server. To run the server at bootup, add this line to either /cfg/$sysname/termrc or /cfg/$sysname/cpurc: ! ndb/dns -nsR * The flag -s allows the DNS server to answer requests sent to UDP port 53. * The flag -r allows ndb/dns to act as a resolver. * The flag -n causes the server to send UDP NOTIFY messages to DNS slaves. * The flag -R causes ndb/dns to ignore recursive lookups on behalf of remote systems. This can help prevent DDoS amplification attacks. Note: Networking must be configured before running ndb/dns(8). Otherwise, you might see the following errors: ! ndb/dns: can't read my ip address Next, add records to /lib/ndb/local, similar to the following: ! sys=example dom=example.com ! ether=f2b2b3daeb89 ! ip=198.51.100.2 ipmask=255.255.255.0 ipgw=198.51.100.1 ! ntp=pool.ntp.org ! dns=198.51.100.1 ! auth=198.51.100.1 ! authdom=example.com ! ! dom=example.com soa= ! refresh=300 ttl=300 ! ns=ns1.example.com ! ns=ns2.example.com ! ip=198.51.100.2 ! dnsslave=ns2.example.com ! mb=postmaster@example.com ! mx=mail.example.com pref=5 ! txtrr="v=spf1 mx -all" ! ! dom=ns1.example.com ip=198.51.100.2 ! dom=ns2.example.com ip=198.51.100.2 ! dom=mail.example.com ip=198.51.100.2 ! dom=_dmarc.example.com txtrr="v=DMARC1; p=none" ! dom=p9auth.example.com cname=example.com ! ! dom=2.100.51.198.in-addr.arpa soa= ! refresh=300 ttl=300 ! ns=ns1.example.com ! ns=ns2.example.com Replace 198.51.100.1, 198.51.100.2, example.com, postmaster@example.com, and 2.100.51.198 with your actual values. Note: ndb may be sensitive to poorly formatted whitespace. If ndb is not recognizing your tuples properly, double check your whitespace. Note: Make sure to define your tuple for sys=example.com in /lib/ndb/local right after the definition for localhost, before other tuples. Otherwise, the system might use the wrong subnet mask, causing routing issues. Note: ndb(6) in Plan 9 4th Edition does not document how to handle TXT records, but they can be created with attr txtrr. To refresh cs and dns after an update to /lib/ndb/local: ! ; echo -n refresh > /net/cs ! ; echo -n refresh > /net/dns DELEGATION Suppose you run dns(8) for the server example.com, and you want to delegate subdomain.example.com to another nameserver. Here is a sample snippet to add to /lib/ndb/local for example.com: ! dom=subdomain.example.com soa=delegated ! ns=ns1.subdomain.example.com ! ns=ns2.subdomain.example.com ! dom=ns1.subdomain.example.com ip=198.51.100.3 ! dom=ns2.subdomain.example.com ip=198.51.100.4 Then, in subdomain.example.com, add this to /lib/ndb/local: ! dom=ns1.subdomain.example.com ip=198.51.100.3 ! dom=ns2.subdomain.example.com ip=198.51.100.4 ! ! dom=subdomain.example.com soa= ! refresh=300 ttl=300 ! ns=ns1.subdomain.example.com ! ns=ns2.subdomain.example.com ! ip=198.51.100.3 ! dnsslave=ns2.subdomain.example.com ! mb=username@subdomain.example.com ! mx=mail.subdomain.example.com ! txtrr="v=spf1 mx -all" ! ! dom=3.100.51.198.in-addr.arpa soa= ! refresh=300 ttl=300 ! ns=ns1.subdomain.example.com ! ns=ns2.subdomain.example.com DNS ERRORS Occasionally, this error may occur: ! dns: file does not exist: /fd/0:3: < can't open: $user: '$user' directory entry not found ! /fd/0:4: /net/net/clone: '/net/net/clone' dns: file does not exist This may mean either cs or ndb is dead. Both can be restarted with: ! ; ndb/cs ! ; kill dns | rc ! ; ndb/dns