doc: max payload documentation updated

doc/man/knot.conf.5in

@@ -147,6 +147,8 @@ server:
     tcp\-reply\-timeout: TIME
     max\-tcp\-clients: INT
     max\-udp\-payload: SIZE
+    max\-ipv4\-udp\-payload: SIZE
+    max\-ipv6\-udp\-payload: SIZE
     rate\-limit: INT
     rate\-limit\-slip: INT
     rate\-limit\-table\-size: INT
@@ -305,7 +307,17 @@ white\-listed.
 \fIDefault:\fP not set
 .SS max\-udp\-payload
 .sp
-Maximum EDNS0 UDP payload size.
+Maximum EDNS0 UDP payload size default for both IPv4 and IPv6.
+.sp
+\fIDefault:\fP 4096
+.SS max\-ipv4\-udp\-payload
+.sp
+Maximum EDNS0 UDP payload size for IPv4.
+.sp
+\fIDefault:\fP 4096
+.SS max\-ipv6\-udp\-payload
+.sp
+Maximum EDNS0 UDP payload size for IPv6.
 .sp
 \fIDefault:\fP 4096
 .SS listen

doc/reference.rst

@@ -100,6 +100,8 @@ General options related to the server.
      tcp-reply-timeout: TIME
      max-tcp-clients: INT
      max-udp-payload: SIZE
+     max-ipv4-udp-payload: SIZE
+     max-ipv6-udp-payload: SIZE
      rate-limit: INT
      rate-limit-slip: INT
      rate-limit-table-size: INT
@@ -328,7 +330,25 @@ white-listed.
 max-udp-payload
 ---------------
 
-Maximum EDNS0 UDP payload size.
+Maximum EDNS0 UDP payload size default for both IPv4 and IPv6.
+
+*Default:* 4096
+
+.. _server_max-ipv4-udp-payload:
+
+max-ipv4-udp-payload
+---------------
+
+Maximum EDNS0 UDP payload size for IPv4.
+
+*Default:* 4096
+
+.. _server_max-ipv6-udp-payload:
+
+max-ipv6-udp-payload
+---------------
+
+Maximum EDNS0 UDP payload size for IPv6.
 
 *Default:* 4096