Configuring and Managing MPE/iX Internet Services (August 2002)

Appendix C
BIND 8.1 Enhanced Features
BIND 8 Highlights
230
statistics-file The pathname of the file the server appends statistics to when it receives
SIGILL signal (ndc stats). If not specified, the default is “named.stats”.
Boolean Options
auth-nxdomain If yes, then the AA bit is always set on NXDOMAIN responses, even if the
server is not actually authoritative. The default is yes. Do not turn off
auth-nxdomain unless you are sure you know what you are doing, as some
older software won’t like it.
deallocate-on-exit If yes, then when the server exits it will painstakingly deallocate every
object it allocated, and then write a memory usage report to the
memstatistics-file. The default is no, because it is faster to let the
operating system clean up. deallocate-on-exit is handy for detecting
memory leaks.
fake-iquery If yes, the server will simulate the obsolete DNS query type IQUERY. The
default is no.
fetch-glue If yes (the default), the server will fetch “glue” resource records it doesn’t
have when constructing the additional data section of a response.
fetch-glue no can be used in conjunction with recursion no to prevent
the server’s cache from growing or becoming corrupted (at the cost of
requiring more work from the client).
host-statistics If yes, then statistics are kept for every host that the nameserver interacts
with. The default is no.
NOTE Turning on host-statistics can consume huge amounts of memory.
multiple-cnames If yes, then multiple CNAME resource records will be allowed for a domain
name. The default is no. Allowing multiple CNAME records is against
standards and is not recommended. Multiple CNAME support is available
because previous versions of BIND allowed multiple CNAME records, and
these records have been used for load balancing by a number of sites.
notify If yes (the default), DNS NOTIFY messages are sent when a zone the server
is authoritative for changes. The use of NOTIFY speeds convergence
between the master and its slaves. Slave servers that receive a NOTIFY
message and understand it, will contact the master server for the zone
and see if they need to do a zone transfer, and if they do, they will initiate
it immediately. The notify option may also be specified in the zone
statement, in which case it overrides the options notify statement.
recursion If yes, and a DNS query requests recursion, then the server will attempt
to do all the work required to answer the query. If recursion is not on, the
server will return a referral to the client if it doesn’t know the answer. The
default is yes. See also fetch-glue.
Forwarding
The forwarding facility can be used to create a large sitewide cache on a few servers, reducing traffic over
links to external nameservers. It can also be used to allow queries by servers that do not have direct access to
the Internet, but wish to look up exterior names anyway. Forwarding occurs only on those queries for which
the server is not authoritative and does not have the answer in its cache.