The following guide applies to TCP/IP Services version 5.4 (HP TCP/IP Services for OpenVMS Alpha Version V5.4).

How can I enable IPv6 on OpenVMS?

To configure the node as an IPv6 host first login as system user, then call TCPIP$IP6_SETUP.COM. Answering with the default

• settings should be ok. If there's an IPv6 capable router in your network which advertises itself, then the host address will be configured automatically too. After that if the node has got both IPv4 and IPv6 addresses, the IPv6 stack will be used.

   $ @SYS$MANAGER:TCPIP$IP6_SETUP

                IPv6 Network Configuration Procedure
  
       This procedure helps you define the parameters required to
       enable IPv6.
  
       This procedure will gather IPv4 information from  your  system
       then prompt you for IPv6 related information.  You may enter a
       question mark (?) at any question for further explanation.
  
       This system can be configured as a IPv6 Host or an IPv6 Router.
  
       As an IPv6 Host,  a system can autoconfigure its IPv6 address(es).  If
       there is an IPv6 router on the same  link  as  this  host  then  it is
       capable of autoconfiguring an IPv6 global address  on  its  interfaces
       based on the information carried in Router Advertisements sent by  the
       router.
  
       As an IPv6 Router,  a system is  responsible  for advertising  one  or
       more address  prefixes to other IPv6 hosts on the link from which they
       can  autoconfigure  globally  routable  addresses, and  for forwarding
       packets destined for remote address prefixes. If you  answer "YES"  to
       this  question,  you will be  prompted  for address  prefixes  on each
       interface.
  
   Configure this system as an IPv6 router? [NO]:
  
  No, only a host.
  
       This system  can  be  configured  as  a 6to4  isolated  host  with  no
       connection to an IPv6 network. If this  system is a host within a IPv6
       or a  6to4 site, do  not create a 6to4 interface. An IPv6 address or a
       6to4 address will  be automatically  configured  on this  system using
       the standard IPv6 mechanisms.
  
       A  6to4 interface  is needed  only if  this system is an isolated host
       with  no connection  to the  IPv6 network.
  
   Configure a 6to4 interface? [NO]:
  
       Do you want to enable IPv6 on this interface?
  
   Enable IPv6 on interface WE0? [YES]:
  
  Yes, that's what we want.
  
       Automatic tunnels allow multiple IPv6 nodes  connected  to  an  IPv4
       network  to  communicate  with  IPv6  messages  without   explicitly
       creating  configured  tunnels between each pair of nodes.  Automatic
       tunnel  endpoints are identified by IPv4-Compatible  IPv6  addresses
       of  the  form ::ddd.ddd.ddd.ddd.  The last four bytes  of  an  IPv4-
       Compatible address define the IPv4 address of the  tunnel  endpoint.
       HP recommends you avoid  using  automatic  tunnels  due to potential
       IPv4-Compatible  address  routing problems.  Answer "YES" to  enable
       automatic tunnels on this system.
  
   Configure an IPv6 over IPv4 automatic tunnel interface? [NO]:
  
       An IPv6 over IPv4 configured  tunnel  allows  an  IPv6  node  to
       communicate with another IPv6 node across an IPv4 network.  IPv6
       messages are encapsulated inside IPv4 messages for transmission.
       Each  configured  tunnel has just one source and one destination
       in the IPv4 network.  Answer "YES" to create a configured tunnel
       on this system.
  
   Create a configured tunnel? [NO]:
  
       Create IPv6 Host configuration file?
  
   Please enter YES or NO [YES]:
  
  Yes, save it.
  
       A  new  IPv6  configuration file, SYS$SYSTEM:TCPIP$INET6_CONFIG.DAT,
       has been created.  The previous configuration file (if any) has been
       renamed to SYS$SYSTEM:TCPIP$INET6_CONFIG.DAT_OLD.
  
       This new IPv6 configuration will become active the next time  TCP/IP
       Services for OpenVMS is started.

Then restart the TCP/IP services, and IPv6 should be working.

How to check if IPv6 enabled on OpenVMS?

Check the configuration with listing the interface parameters.

•  $ TCPIP
   TCPIP> ifconfig we0
   WE0: flags=c43<UP,BROADCAST,RUNNING,MULTICAST,SIMPLEX>
       *inet 193.6.5.197 netmask ffffff00 broadcast 193.6.5.255 ipmtu 1500
        inet6 fe80::a00:2bff:fee7:eb88
        inet6 2001:738:6001:500:a00:2bff:fee7:eb88
  
   TCPIP> ifconfig lo0
   LO0: flags=100c89<UP,LOOPBACK,NOARP,MULTICAST,SIMPLEX,NOCHECKSUM>
        inet 127.0.0.1 netmask ff000000 ipmtu 4096
        inet6 ::1

Can be easily tested with a simple ping:

•  TCPIP> ping suti.iit.uni-miskolc.hu
   PING suti.iit.uni-miskolc.hu (2001:738:6001:500::ffff): 56 data bytes
   64 bytes from 2001:738:6001:500::ffff: icmp6_seq=0 hlim=64 time=2 ms
   64 bytes from 2001:738:6001:500::ffff: icmp6_seq=1 hlim=64 time=1 ms
   64 bytes from 2001:738:6001:500::ffff: icmp6_seq=2 hlim=64 time=1 ms
   64 bytes from 2001:738:6001:500::ffff: icmp6_seq=3 hlim=64 time=1 ms
  
  
   ----suti.iit.uni-miskolc.hu PING Statistics----
   4 packets transmitted, 4 packets received, 0% packet loss
   round-trip (ms)  min/avg/max = 1/1/2 ms
  
   TCPIP> ping skye.ki.iif.hu
   PING skye.ki.iif.hu (2001:738:0:402::2): 56 data bytes
   64 bytes from 2001:738:0:402::2: icmp6_seq=0 hlim=60 time=8 ms
   64 bytes from 2001:738:0:402::2: icmp6_seq=1 hlim=60 time=5 ms
   64 bytes from 2001:738:0:402::2: icmp6_seq=2 hlim=60 time=5 ms
   64 bytes from 2001:738:0:402::2: icmp6_seq=3 hlim=60 time=5 ms
  
  
   ----skye.ki.iif.hu PING Statistics----
   4 packets transmitted, 4 packets received, 0% packet loss
   round-trip (ms)  min/avg/max = 5/6/8 ms

Or with traceroute:

•  TCPIP> trace skye.ki.iif.hu
   traceroute to skye.ki.iif.hu (2001:738:0:402::2): 1-30 hops,  64 byte packets
    1  suti6.iit.uni-miskolc.hu (2001:738:6001:500::ffff)  1.953 ms  1.953 ms  1.95  3 ms
    2  2001:738:6000:200::1 (2001:738:6000:200::1)  1.953 ms  1.953 ms  0.976 ms
    3  lo0.c6509.vh.hbone.hu (2001:738:0:4::1)  5.859 ms  4.882 ms  5.859 ms
    4  2001:738:0:406::1 (2001:738:0:406::1)  5.859 ms  4.883 ms  5.859 ms
    5  skye.ki.iif.hu (2001:738:0:402::2)  7.812 ms  6.836 ms  5.859 ms

On top of that, the neighbour discovery daemon should appear among the processes.

•  $ show system
  
   ...
   00000216 TCPIP$ND6HOST   LEF      9  8923101   0 00:00:19.14       372    230
   ...