added documentation for size limits

Author: FreeAndNil

src/site/antora/modules/ROOT/pages/manual/configuration/appenders/remotesyslogappender.adoc

@@ -57,6 +57,9 @@ You can also specify:
 </appender>
 ----
 
+[#newlinehandling]
+== Newline handling
+
 If your log message contains multiple lines, it will be logged as multiple separate syslog entries instead of a single multiline message.
 
 This might lead to confusion when analyzing logs because related lines could appear interleaved with logs from other sources.
@@ -85,4 +88,16 @@ Exception of type 'System.InvalidTimeZoneException' was thrown.
   at log4net.Tests.Appender.RemoteSyslogAppenderTest.LineBreakTest()
   at System.RuntimeMethodHandle.InvokeMethod(Object target, Void** arguments, Signature sig, Boolean isConstructor)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)
-----
+----
+
+[#sizelimits]
+== Size limits
+
+The `RemoteSyslogAppender` uses the UDP protocol to send log messages to the syslog server.
+However, there are size limitations associated with UDP:
+
+* **Message size:** Each log message is limited to **64 KB**, including both the message content and the headers.
+* **Practical size limit:** On many networks, such as Ethernet, the practical limit for message size is typically much lower — around **1500 bytes**.
+* **Message truncation:** If a log message exceeds these size limits, it will be **truncated**, which means some of the message content will be lost.
+
+To avoid truncation, ensure that log messages are kept within the size limits of your network setup.