Using an IP Routing Table to Route TCP/IP Packets to another TCP/IP Host

When a SCADAPack x70 device routes a TCP/IP packet to another TCP/IP host, the following rules are applied in order, until the packet has been sent or discarded:

1. If the TCP/IP packet has a destination address that matches a host on the same subnet as one of the Ethernet interfaces, the SCADAPack x70 device routes the TCP/IP packet directly via that Ethernet interface.
2. If the TCP/IP packet has a destination address that matches a host on the same subnet as a serial PPP interface with a configured subnet, then the SCADAPack x70 device routes the TCP/IP packet directly via that Serial interface.
3. If the packet has not been sent in the steps above, the SCADAPack x70 device looks up the destination address of the packet in its IP Routing Table. It searches the entries in the routing table in Host, Network, and then Gateway order. If a match is found, the SCADAPack x70 device routes the packet to the corresponding gateway via the corresponding port.
4. If the packet has not been sent in the steps above, the SCADAPack x70 device reverts to using to its default Gateway. This is specified outside of the IP Routing Table, using the Gateway IP Address field in the Ethernet Ports section of the Device Configuration item's IP Communications tab (see Configure Ethernet Ports). The SCADAPack x70 device routes the packet through the default gateway node.
5. If no Gateway IP address is configured and there is one serial PPP interface configured, the SCADAPack x70 device routes each TCP/IP packet via that Serial interface.
6. The packet is discarded.