Note that interfaces may have numerical names.

If N is a number, and is the name of an interface on the system, "-i N"
will now attempt to open that interface, not the Nth interface in the
list of interfaces.  See GitHub issue #522.

diff --git a/tcpdump.1.in b/tcpdump.1.in
index 2de8daa41cde6a24c833cf4c6c0928878d9148b4..f04a57933623a695b23e28d934fbf6b0a9d7225e 100644 (file)
--- a/tcpdump.1.in
+++ b/tcpdump.1.in
@@ -400,7 +400,7 @@ If the
 flag is supported, an interface number as printed by that flag can be
 used as the
 .I interface
-argument.
+argument, if no interface on the system has that number as a name.
 .TP
 .B \-I
 .PD 0