Black Box LR5100A-T - Manual (Page 24)

Applications
16
IP Routing
An Ethernet IP router is used to intelligently route Internet Protocol (IP) traffic to another
network. The networks may be connected across a WAN link (illustrated below) or two
LANs connected to the same dual LAN router.
Figure 2 -2 IP Networks Routed across a WAN link
IP routers forward IP frames based upon their IP destination address and an internal
routing table. The router maintains the internal routing table with the connected network IP
addresses and, for WAN link connections, the remote partner IP routers associated with
those networks. When an IP frame is received, the destination IP address is examined and
looked up in the routing table. In the case of a dual LAN router, if the destination IP
address is on the other LAN, the packet is routed there. For WAN connections, if the
destination IP network is found in the routing tables, the IP router sends the IP frame to the
remote partner router that is connected to the appropriate remote IP network. If no explicit
route entry is found in the routing table, the IP frame is sent to the Default Gateway. The
Default Gateway may be learned from the LAN or may be set manually (see section 2.1.2.3).
To configure an router for IP routing between networks, the following parameters must be
defined in the built-in menu system.
1. IP Address
Location: Main
Ä
Configuration
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LAN Set-up
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LAN IP Set-up
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IP Address / Size of Subnet Mask
If this router has the dual LAN option installed, you will first be asked which LAN to
reference (1 or 2). Both LANs must have unique IP addresses to use IP routing.
7
WAN connection
TCP/IP Network TCP/IP Network
Network #1
IP Network Address
199.169.1.0
IP Network Address
199.169.2.0
Router IP Address
199.169.2.12
Router IP Address
199.169.1.10
Network #2