diff --git a/bin/dig/dig.1 b/bin/dig/dig.1 index 62e15f7410..fdffde7f5c 100644 --- a/bin/dig/dig.1 +++ b/bin/dig/dig.1 @@ -13,7 +13,7 @@ .\" NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION .\" WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" -.\" $Id: dig.1,v 1.1 2000/09/03 18:04:24 jim Exp $ +.\" $Id: dig.1,v 1.2 2000/09/08 09:42:56 jim Exp $ .\" .Dd Jun 30, 2000 .Dt DIG 1 @@ -57,7 +57,7 @@ Other lookup tools tend to have less functionality than .Nm dig . .Pp Although -.NM dig +.Nm dig is normally used with command-line arguments, it also has a batch mode of operation for reading lookup requests from a file. A brief summary of its command-line arguments and options is printed @@ -69,15 +69,43 @@ Unlike earlier versions, the BIND9 implementation of .Nm dig allows multiple lookups to be issued from the command line. .Pp +Unless it is told to query a specific name server, +.Nm dig +will read +.Pa /etc/resolv.conf +and send queries to the name servers identified by the +.Nm nameserver +directives in that file. +Those name servers are queried in sequence. +.Nm dig +dig will send its query to the first name server listed in +.Pa /etc/resolv.conf . +If the query times out, +.Nm dig +then tries the second name server in the list and if that query +times out, it will try the third name server. +When the query to that third name server times out, +.Nm dig +repeats the lookups. +It will try all three servers in sequence again and use a longer timeout +interval for the second series of lookup attempts. +If no answer is returned after the the second round of queries, the +lookup fails. +.Pp +The lookup completes when an answer is returned, even if that +answer indicates an error. +A commonly held misconception is that the resolver used by tools like +.Nm dig +will repeat the query to the next name server listed in +.Pa /etc/resolv.conf +if the name server that was queried returns an error reply. +This is not so. +.Pp When no command line arguments or options are given, .Nm dig reads .Pa /etc/resolv.conf -and sends a query in parallel -for details of the root zone \*q.\*q. -to each of the name servers listed in that file. -The reply from the name server that responds first is printed -and any other replies are discarded. +and makes a lookup for details of the root zone \*q.\*q .Sh SIMPLE USAGE .Pp In normal usage, a typical invocation of @@ -103,8 +131,8 @@ argument is provided, .Nm dig consults .Pa /etc/resolv.conf -and sends parallel queries to each of the name servers listed there. -The reply from the first name server to respond is displayed. +and queries the name servers listed there. +The reply from the name server that responds is displayed. .It Ar name is the name of the resource record that is to be looked up. .It Ar type @@ -802,6 +830,18 @@ which returns the eventual answer. .Xr RFC1035 , .Xr RFC2535 . .Sh BUGS +Truncated replies are handled differently in the BIND9 implementation +of +.Nm dig . +In previous versions, +.Nm dig +would automatically repeat the query using TCP whenever it received +a truncated response. +The BIND9 implementation does not do this. +It will just display the truncated response unless +.Nm dig +was told to use a TCP connection when making queries. +.Pp The .Fl x flag and diff --git a/doc/man/bin/dig.1 b/doc/man/bin/dig.1 index 62e15f7410..fdffde7f5c 100644 --- a/doc/man/bin/dig.1 +++ b/doc/man/bin/dig.1 @@ -13,7 +13,7 @@ .\" NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION .\" WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. .\" -.\" $Id: dig.1,v 1.1 2000/09/03 18:04:24 jim Exp $ +.\" $Id: dig.1,v 1.2 2000/09/08 09:42:56 jim Exp $ .\" .Dd Jun 30, 2000 .Dt DIG 1 @@ -57,7 +57,7 @@ Other lookup tools tend to have less functionality than .Nm dig . .Pp Although -.NM dig +.Nm dig is normally used with command-line arguments, it also has a batch mode of operation for reading lookup requests from a file. A brief summary of its command-line arguments and options is printed @@ -69,15 +69,43 @@ Unlike earlier versions, the BIND9 implementation of .Nm dig allows multiple lookups to be issued from the command line. .Pp +Unless it is told to query a specific name server, +.Nm dig +will read +.Pa /etc/resolv.conf +and send queries to the name servers identified by the +.Nm nameserver +directives in that file. +Those name servers are queried in sequence. +.Nm dig +dig will send its query to the first name server listed in +.Pa /etc/resolv.conf . +If the query times out, +.Nm dig +then tries the second name server in the list and if that query +times out, it will try the third name server. +When the query to that third name server times out, +.Nm dig +repeats the lookups. +It will try all three servers in sequence again and use a longer timeout +interval for the second series of lookup attempts. +If no answer is returned after the the second round of queries, the +lookup fails. +.Pp +The lookup completes when an answer is returned, even if that +answer indicates an error. +A commonly held misconception is that the resolver used by tools like +.Nm dig +will repeat the query to the next name server listed in +.Pa /etc/resolv.conf +if the name server that was queried returns an error reply. +This is not so. +.Pp When no command line arguments or options are given, .Nm dig reads .Pa /etc/resolv.conf -and sends a query in parallel -for details of the root zone \*q.\*q. -to each of the name servers listed in that file. -The reply from the name server that responds first is printed -and any other replies are discarded. +and makes a lookup for details of the root zone \*q.\*q .Sh SIMPLE USAGE .Pp In normal usage, a typical invocation of @@ -103,8 +131,8 @@ argument is provided, .Nm dig consults .Pa /etc/resolv.conf -and sends parallel queries to each of the name servers listed there. -The reply from the first name server to respond is displayed. +and queries the name servers listed there. +The reply from the name server that responds is displayed. .It Ar name is the name of the resource record that is to be looked up. .It Ar type @@ -802,6 +830,18 @@ which returns the eventual answer. .Xr RFC1035 , .Xr RFC2535 . .Sh BUGS +Truncated replies are handled differently in the BIND9 implementation +of +.Nm dig . +In previous versions, +.Nm dig +would automatically repeat the query using TCP whenever it received +a truncated response. +The BIND9 implementation does not do this. +It will just display the truncated response unless +.Nm dig +was told to use a TCP connection when making queries. +.Pp The .Fl x flag and