5.7.1 External Access to an Internally installed Card using IPv4

The following procedure allows the card to be accessed additionally from another PC (Other-PC ) on an IPv4 sub-net which differs from that used by the Host-PC and card.

Note
We assume throughout this procedure that your Host-PC and Other-PC are both already visible to each other via some existing IPv4 network topology. For example, let's say they are both members of an existing sub-net "11.2.0.0 / 16": Host-PC Other-PC IP Address = 11.2.69.13 Netmask = 255.255.0.0 IP Address = 11.2.69.42 Netmask = 255.255.0.0

Important
All addresses and sub-nets mentioned here are strictly for example only! You will need to substitute your own suitable values.

1. Enable IP-Packet-Forwarding functionality on the Host-PC.

   This step is necessary to ensure that the card and the Other-PC can exchange IP packets via the Host-PC.

   • Please follow the standard procedure for your Host-PC's operating system to enable IP packet forwarding (sometimes simply called packet routeing or router functionality ).

2. Choose routeable IPv4 Addresses and Netmasks for both end-points of the Virtual Ethernet Cable between the Host-PC and the SP-ICE-3 Card.

   Important
   Make sure that they belong to the same IPv4 Sub-Net!

   • For our example, we choose the sub-net "11.2.123.0 / 24":

     Card End-Point	Host End-Point
     IP Address = 11.2.123.1 Netmask = 255.255.255.0	IP Address = 11.2.123.2 Netmask = 255.255.255.0

3. Manually assign your chosen routeable IPv4 address and netmask, and the Default Gateway on the SP-ICE-3 Card.

   The following steps are necessary to ensure that the card knows how to send packets to the Other-PC, even though it belongs to a different sub-net.

   • Access the card's WebInterface (see: 17.2 How to Open the Card's Web Interface).

   • On the NETWORK page, enter your chosen routeable IPv4 address and netmask, for eth1, which is the card's end-point of the Virtual Ethernet Cable.

     • Thus in our example, IP Address = "11.2.123.1" and Netmask = "255.255.255.0".

     Please refer to:5.5.3 Manually configuring the Card's IPv4-Address seen by the Host.

   • On the NETWORK page, the Default Gateway entry field becomes visible after you have changed the IP-Address field to something other than "DHCP", and saved the settings by clicking the Save Network Settings button.

   • Specify the Default Gateway to be the same IPv4 address that you chose for the Host-PC's end-point of the Virtual Ethernet Cable.

     • For our example, Default Gateway = "11.2.123.2".

   • Reboot the SP-ICE-3 Card.

     Important
     Be aware that when the card reboots, you may be temporarily unable to make further contact with it from the Host-PC until you have completed the rest of the procedure.

4. Manually assign your chosen routeable IPv4 address and netmask to the Host-PC's end-point of the Virtual Ethernet Cable

   • For our example, IP Address = "11.2.123.2" and Netmask = "255.255.255.0".

   Please refer to: 5.5.4 Manually configuring the Host IPv4-Address seen by the Card

   After completing this step, you should be able to re-establish contact between the Host-PC and the SP-ICE-3 Card.

    

5. On the Other-PC, add an routeing table entry for the IPv4 address that you chose for the card's end-point of the Virtual Ethernet Cable.

   This step is necessary to ensure that the Other-PC knows where to send IPv4 packets destined for the card, even though the card is on a different sub-net.

   The additional entry must specify that packets destined for the card's address should be routed via the Host-PC.

   • For our example, IP Address "11.2.123.1" with Netmask = "255.255.255.0" should be routed via "11.2.69.13".

   • Please follow the standard procedure for your Other-PC's operating system to add the routeing table entry.