Improve RFC links (#8612)

The `tools.ietf.org` site now redirects to `www.rfc-editor.org`.
* Update various URLs to the new site.
* Make links to `www.rfc-editor.org` consistent.

Signed-off-by: SuperQ <superq@gmail.com>

man/coredns-dnstap.7

@@ -1,5 +1,5 @@
 .\" Generated by Mmark Markdown Processer - mmark.miek.nl
-.TH "COREDNS-DNSTAP" 7 "March 2026" "CoreDNS" "CoreDNS Plugins"
+.TH "COREDNS-DNSTAP" 7 "October 2026" "CoreDNS" "CoreDNS Plugins"
 
 .SH "NAME"
 .PP
@@ -16,6 +16,7 @@ Every message is sent to the socket as soon as it comes in, the \fIdnstap\fP plu
 10000 messages, above that number dnstap messages will be dropped (this is logged).
 
 .SH "SYNTAX"
+.SS "OUTGOING CONNECTIONS (CONNECT TO SINK)"
 .PP
 .RS
 
@@ -49,6 +50,44 @@ dnstap SOCKET [full] [writebuffer] [queue] {
 \fB\fCskipverify\fR to skip tls verification during connection. Default to be secure
 
 
+.SS "INCOMING CONNECTIONS (ACCEPT FROM SINKS)"
+.PP
+.RS
+
+.nf
+dnstap listen SOCKET [full] {
+  [identity IDENTITY]
+  [version VERSION]
+  [extra EXTRA]
+  [tls CERT KEY [CA]]
+  [skipverify]
+}
+
+.fi
+.RE
+
+.IP \(bu 4
+\fB\fClisten\fR indicates this is a listening socket that accepts incoming connections from dnstap sinks.
+.IP \(bu 4
+\fBSOCKET\fP is the socket address to listen on (e.g., \fB\fCtcp://127.0.0.1:6000\fR, \fB\fCunix:///tmp/dnstap.sock\fR).
+.IP \(bu 4
+\fB\fCfull\fR to include the wire-format DNS message.
+.IP \(bu 4
+\fBIDENTITY\fP to override the identity of the server. Defaults to the hostname.
+.IP \(bu 4
+\fBVERSION\fP to override the version field. Defaults to the CoreDNS version.
+.IP \(bu 4
+\fBEXTRA\fP to define "extra" field in dnstap payload, metadata
+\[la]../metadata/\[ra] replacement available here.
+.IP \(bu 4
+\fB\fCtls CERT KEY [CA]\fR to enable TLS for the listener. \fBCERT\fP and \fBKEY\fP are paths to the server certificate and key files. Optional \fBCA\fP is the path to the CA certificate for client verification.
+.IP \(bu 4
+\fB\fCskipverify\fR to skip client certificate verification. Default is to verify client certificates. Equivalent to the \fBCA\fP option above being unspecified.
+
+
+.PP
+\fBNote:\fP Incoming connections use unbuffered channels to broadcast events. If a connected sink becomes slow or disconnected, messages are dropped for that sink only, and the connection is closed.
+
 .SH "EXAMPLES"
 .PP
 Log information about client requests and responses to \fI/tmp/dnstap.sock\fP.
@@ -155,6 +194,59 @@ dnstap tls://127.0.0.1:6000 full {
 .fi
 .RE
 
+.PP
+Listen for incoming dnstap sink connections on a Unix socket.
+
+.PP
+.RS
+
+.nf
+dnstap listen /tmp/dnstap.sock full
+
+.fi
+.RE
+
+.PP
+Listen for incoming dnstap sink connections on TCP.
+
+.PP
+.RS
+
+.nf
+dnstap listen tcp://127.0.0.1:6000 full
+
+.fi
+.RE
+
+.PP
+Listen for incoming dnstap sink connections on TLS with mTLS client authentication.
+
+.PP
+.RS
+
+.nf
+dnstap listen tls://127.0.0.1:6000 full {
+  tls /path/to/server\-cert.pem /path/to/server\-key.pem /path/to/ca.pem
+}
+
+.fi
+.RE
+
+.PP
+Listen for incoming dnstap sink connections on TLS without client certificate verification.
+
+.PP
+.RS
+
+.nf
+dnstap listen tls://127.0.0.1:6000 full {
+  tls /path/to/server\-cert.pem /path/to/server\-key.pem
+  skipverify
+}
+
+.fi
+.RE
+
 .PP
 You can use \fIdnstap\fP more than once to define multiple taps. The following logs information including the
 wire-format DNS message about client requests and responses to \fI/tmp/dnstap.sock\fP,
@@ -170,6 +262,19 @@ dnstap tcp://example.com:6000
 .fi
 .RE
 
+.PP
+You can also combine outgoing connections with incoming listeners:
+
+.PP
+.RS
+
+.nf
+dnstap tcp://remote\-collector.example.com:6000 full
+dnstap listen tcp://127.0.0.1:6001 full
+
+.fi
+.RE
+
 .SH "COMMAND LINE TOOL"
 .PP
 Dnstap has a command line tool that can be used to inspect the logging. The tool can be found