OT$ tcpip show ver HP TCP/IP Services for OpenVMS Alpha Version V5.4 on a AlphaServer ES40 running OpenVMS V7.3-2 OT$ ifconfig -a IE0: flags=c43 *inet 206.157.122.22 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 inet 206.157.122.20 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 LO0: flags=100c89 TN0: flags=80 TN1: flags=80 OT$ netstat -rn Routing tables Destination Gateway Flags Refs Use Interface Route Tree for Protocol Family 26: Route Tree for Protocol Family 2: default 206.157.122.1 UGS 2 663871 IE0 127.0.0.1 127.0.0.1 UHL 2 925 LO0 206.157.122/24 206.157.122.22 U 1 1277184 IE0 206.157.122.20 206.157.122.20 UHL 0 0 IE0 206.157.122.22 206.157.122.22 UHL 2 249 IE0 OT$ ifconfig ie0 alias 16.16.16.16/23 ! add a secondary ip addresss to the interface with /23 OT$ ifconfig -a IE0: flags=8000c43 *inet 206.157.122.22 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 inet 206.157.122.20 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 inet 16.16.16.16 netmask fffffe00 broadcast 16.16.17.255 ipmtu 1500 LO0: flags=100c89 TN0: flags=80 TN1: flags=80 OT$ netstat -rn Routing tables Destination Gateway Flags Refs Use Interface Route Tree for Protocol Family 26: Route Tree for Protocol Family 2: default 206.157.122.1 UGS 2 663959 IE0 16.16.16/23 16.16.16.16 U 1 0 IE0 16.16.16.16 16.16.16.16 UHL 0 0 IE0 127.0.0.1 127.0.0.1 UHL 2 926 LO0 206.157.122/24 206.157.122.22 U 1 1277184 IE0 206.157.122.20 206.157.122.20 UHL 0 0 IE0 206.157.122.22 206.157.122.22 UHL 2 251 IE0 OT$ ! that looks like what I would expect, it added the correct route to the routing table OT$ ifconfig ie0 -alias 16.16.16.16 ! remove the secondary address that was just added OT$ ifconfig -a IE0: flags=c43 *inet 206.157.122.22 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 inet 206.157.122.20 netmask ffffff00 broadcast 206.157.122.255 ipmtu 1500 LO0: flags=100c89 TN0: flags=80 TN1: flags=80 OT$ netstat -rn Routing tables Destination Gateway Flags Refs Use Interface Route Tree for Protocol Family 26: Route Tree for Protocol Family 2: default 206.157.122.1 UGS 2 664004 IE0 127.0.0.1 127.0.0.1 UHL 2 928 LO0 206.157.122/24 206.157.122.22 U 1 1277184 IE0 206.157.122.20 206.157.122.20 UHL 0 0 IE0 206.157.122.22 206.157.122.22 UHL 2 251 IE0 OT$ ! routing table is back to what it was