diff -ur tcpdump-3.7.1~/addrtoname.c tcpdump-3.7.1/addrtoname.c
--- tcpdump-3.7.1~/addrtoname.c	Tue Sep 18 01:57:50 2001
+++ tcpdump-3.7.1/addrtoname.c	Tue Apr  9 19:11:57 2002
@@ -656,7 +656,7 @@
 
 		while (table->name)
 			table = table->nxt;
-		if (nflag) {
+		if (nflag > 1) {
 			(void)snprintf(buf, sizeof(buf), "%d", port);
 			table->name = strdup(buf);
 		} else
@@ -845,7 +845,7 @@
 		f_localnet = localnet;
 		f_netmask = mask;
 	}
-	if (nflag)
+	if (nflag > 1)
 		/*
 		 * Simplest way to suppress names.
 		 */
diff -ur tcpdump-3.7.1~/tcpdump.1 tcpdump-3.7.1/tcpdump.1
--- tcpdump-3.7.1~/tcpdump.1	Fri Jan  4 10:37:49 2002
+++ tcpdump-3.7.1/tcpdump.1	Tue Apr  9 19:11:57 2002
@@ -272,7 +272,11 @@
 can be used several times to load several MIB modules into \fItcpdump\fP.
 .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.