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Figure 2. Securing Small Branch Office with a Cisco 1800 Series Fixed-Configuration Router
Highly Available Internet Connection
The Cisco IOS Software Advanced IP Services feature set offers basic and advanced routing capabilities to deliver failover protection and load
balancing. These capabilities include Border Gateway Protocol (BGP), Open Shortest Path First (OSPF) Protocol, Enhanced Interior Gateway
Routing Protocol (EIGRP), and Routing Information Protocol (RIP) routing protocols along with dial-on-demand routing (DDR) and reliable static
routing using object tracking. Each of the Cisco 1800 Series fixed-configuration routers is equipped with either an ISDN BRI, V.92 analog modem,
or Ethernet port for secondary WAN backup connection. If the primary DSL, cable, or Ethernet-access WAN is disconnected for some reason, the
router will detect this failure and will fail over to the secondary backup WAN. As Figure 3 and 4 demonstrate, the Cisco 1800 Series fixed-
configuration routers help enable customers to deliver high-performance and high-availability, mission-critical business applications.
Figure 3. High-Availability Small Branch Network with Cisco 1811 or 1812 Router
Figure 4. High-Availability Small Branch Network with Cisco 1801, 1802, or 1803 Router