diff --git a/lib/libalias/HISTORY b/lib/libalias/HISTORY
index c690b588ce4b..78a7e08c14f3 100644
--- a/lib/libalias/HISTORY
+++ b/lib/libalias/HISTORY
@@ -41,9 +41,14 @@ Verstion 1.7: January 9, 1997 (cjm)
       from two hosts which are both running packet
       aliasing.
 
+    - Checksum error on FTP transfers.  Problem
+      in code located by Martin Renters and
+      Brian Somers.
+
 Version 1.8: January 14, 1997 (cjm)
     - Fixed data type error in function StartPoint()
       in alias_db.c (this bug did not exist before v1.7)
+      Problem in code located by Ari Suutari.
 
 Version 1.9: February 1, 1997 (Eivind Eklund <perhaps@yes.no>)
     - Added support for IRC DCC (ee)
@@ -108,5 +113,10 @@ Version 2.3: August 11, 1997 (cjm)
     - Problem associated with socket file descriptor
       accumulation in alias_db.c corrected.  The sockets
       had to be closed when a binding failed.  Problem 
-      identified by Gordon Burditt.
+      in code located by Gordon Burditt.
+
+Version 2.4: September 1, 1997 (cjm)
+    - PKT_ALIAS_UNREGISTERED_ONLY option repaired.
+      This part of the code was incorrectly re-implemented
+      in version 2.1.
 
diff --git a/lib/libalias/Makefile b/lib/libalias/Makefile
index d7eab422af7a..3c291b29146e 100644
--- a/lib/libalias/Makefile
+++ b/lib/libalias/Makefile
@@ -1,6 +1,6 @@
 LIB=	alias
 SHLIB_MAJOR= 2
-SHLIB_MINOR= 3
+SHLIB_MINOR= 4
 CFLAGS+=-Wall -I${.CURDIR}
 SRCS=	alias.c alias_db.c alias_ftp.c alias_irc.c alias_util.c alias_old.c
 MAN3=libalias.3 
diff --git a/lib/libalias/alias.c b/lib/libalias/alias.c
index 9bf28d3fb066..a9c1e3b30584 100644
--- a/lib/libalias/alias.c
+++ b/lib/libalias/alias.c
@@ -1064,7 +1064,7 @@ PacketAliasOut(char *ptr,           /* valid IP packet */
         else if (addr >= UNREG_ADDR_A_LOWER && addr <= UNREG_ADDR_A_UPPER)
             iclass = 1;
 
-        if (iclass != 0)
+        if (iclass == 0)
         {
             SetDefaultAliasAddress(pip->ip_src);
         }
diff --git a/lib/libalias/alias.h b/lib/libalias/alias.h
index f574017dc474..50d80562a961 100644
--- a/lib/libalias/alias.h
+++ b/lib/libalias/alias.h
@@ -143,5 +143,8 @@ extern u_short InternetChecksum(u_short *, int);
 #define PKT_ALIAS_UNRESOLVED_FRAGMENT 3
 #define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4
 
+#undef __libalias_version
+#define __libalias_version "2.4"
+
 #endif
 /*lint -restore */
diff --git a/lib/libalias/libalias.3 b/lib/libalias/libalias.3
index e989d6e9da18..6c86232cc6d7 100644
--- a/lib/libalias/libalias.3
+++ b/lib/libalias/libalias.3
@@ -568,7 +568,7 @@ of data including its checksum.  If the checksum is
 valid, PacketAliasInternetChecksum() will return zero.
 
 .Sh 7. Authors
-Charles Mott (cmott@srv.net), versions 1.0 - 1.8, 2.0 - 2.3. 
+Charles Mott (cmott@srv.net), versions 1.0 - 1.8, 2.0 - 2.4. 
 
 Eivind Eiklund (eivind@freebsd.org), versions 1.8b and 1.9.
 Added IRC support as well as contributing a number of
diff --git a/sys/netinet/libalias/HISTORY b/sys/netinet/libalias/HISTORY
index c690b588ce4b..78a7e08c14f3 100644
--- a/sys/netinet/libalias/HISTORY
+++ b/sys/netinet/libalias/HISTORY
@@ -41,9 +41,14 @@ Verstion 1.7: January 9, 1997 (cjm)
       from two hosts which are both running packet
       aliasing.
 
+    - Checksum error on FTP transfers.  Problem
+      in code located by Martin Renters and
+      Brian Somers.
+
 Version 1.8: January 14, 1997 (cjm)
     - Fixed data type error in function StartPoint()
       in alias_db.c (this bug did not exist before v1.7)
+      Problem in code located by Ari Suutari.
 
 Version 1.9: February 1, 1997 (Eivind Eklund <perhaps@yes.no>)
     - Added support for IRC DCC (ee)
@@ -108,5 +113,10 @@ Version 2.3: August 11, 1997 (cjm)
     - Problem associated with socket file descriptor
       accumulation in alias_db.c corrected.  The sockets
       had to be closed when a binding failed.  Problem 
-      identified by Gordon Burditt.
+      in code located by Gordon Burditt.
+
+Version 2.4: September 1, 1997 (cjm)
+    - PKT_ALIAS_UNREGISTERED_ONLY option repaired.
+      This part of the code was incorrectly re-implemented
+      in version 2.1.
 
diff --git a/sys/netinet/libalias/Makefile b/sys/netinet/libalias/Makefile
index d7eab422af7a..3c291b29146e 100644
--- a/sys/netinet/libalias/Makefile
+++ b/sys/netinet/libalias/Makefile
@@ -1,6 +1,6 @@
 LIB=	alias
 SHLIB_MAJOR= 2
-SHLIB_MINOR= 3
+SHLIB_MINOR= 4
 CFLAGS+=-Wall -I${.CURDIR}
 SRCS=	alias.c alias_db.c alias_ftp.c alias_irc.c alias_util.c alias_old.c
 MAN3=libalias.3 
diff --git a/sys/netinet/libalias/alias.c b/sys/netinet/libalias/alias.c
index 9bf28d3fb066..a9c1e3b30584 100644
--- a/sys/netinet/libalias/alias.c
+++ b/sys/netinet/libalias/alias.c
@@ -1064,7 +1064,7 @@ PacketAliasOut(char *ptr,           /* valid IP packet */
         else if (addr >= UNREG_ADDR_A_LOWER && addr <= UNREG_ADDR_A_UPPER)
             iclass = 1;
 
-        if (iclass != 0)
+        if (iclass == 0)
         {
             SetDefaultAliasAddress(pip->ip_src);
         }
diff --git a/sys/netinet/libalias/alias.h b/sys/netinet/libalias/alias.h
index f574017dc474..50d80562a961 100644
--- a/sys/netinet/libalias/alias.h
+++ b/sys/netinet/libalias/alias.h
@@ -143,5 +143,8 @@ extern u_short InternetChecksum(u_short *, int);
 #define PKT_ALIAS_UNRESOLVED_FRAGMENT 3
 #define PKT_ALIAS_FOUND_HEADER_FRAGMENT 4
 
+#undef __libalias_version
+#define __libalias_version "2.4"
+
 #endif
 /*lint -restore */
diff --git a/sys/netinet/libalias/libalias.3 b/sys/netinet/libalias/libalias.3
index e989d6e9da18..6c86232cc6d7 100644
--- a/sys/netinet/libalias/libalias.3
+++ b/sys/netinet/libalias/libalias.3
@@ -568,7 +568,7 @@ of data including its checksum.  If the checksum is
 valid, PacketAliasInternetChecksum() will return zero.
 
 .Sh 7. Authors
-Charles Mott (cmott@srv.net), versions 1.0 - 1.8, 2.0 - 2.3. 
+Charles Mott (cmott@srv.net), versions 1.0 - 1.8, 2.0 - 2.4. 
 
 Eivind Eiklund (eivind@freebsd.org), versions 1.8b and 1.9.
 Added IRC support as well as contributing a number of