diff -uNr tcpdump-3.6.1.orig/addrtoname.c tcpdump-3.6.1/addrtoname.c

--- tcpdump-3.6.1.orig/addrtoname.c	Sat Jan 13 20:01:00 2001

+++ tcpdump-3.6.1/addrtoname.c	Sat Jan 13 19:59:23 2001

@@ -581,7 +581,7 @@

 		while (table->name)

 			table = table->nxt;

-		if (nflag) {

+		if (nflag > 1) {

 			(void)snprintf(buf, sizeof(buf), "%d", port);

 			table->name = strdup(buf);

 		} else

@@ -745,7 +745,7 @@

 		f_localnet = localnet;

 		f_netmask = mask;

 	}

-	if (nflag)

+	if (nflag > 1)

 		/*

 		 * Simplest way to suppress names.

 		 */

diff -uNr tcpdump-3.6.1.orig/tcpdump.1 tcpdump-3.6.1/tcpdump.1

--- tcpdump-3.6.1.orig/tcpdump.1	Sat Jan 13 19:51:47 2001

+++ tcpdump-3.6.1/tcpdump.1	Sat Jan 13 19:50:19 2001

@@ -175,7 +175,11 @@

 ``tcpdump\ \ \-l \ \ > dat\ \ &\ \ tail\ \ \-f\ \ dat''.

 .TP

 .B \-n

-Don't convert addresses (i.e., host addresses, port numbers, etc.) to names.

+Don't convert host addresses to names.  This can be used to avoid 

+DNS lookups.

+.TP

+.B \-nn

+Don't convert protocol and port numbers etc. to names either.  

 .TP

 .B \-N

 Don't print domain name qualification of host names.  E.g.,