Alteon Application Switch Operating System Application Guide
Open Shortest Path First (OSPF)
Document ID: RDWR-ALOS-V2900_AG1302
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All four host routes are injected into the upstream router and advertised externally. Traffic comes in
for both virtual server IP addresses (10.10.10.1 and 10.10.10.2). The upstream router sees that
both addresses exist on both devices and uses the host route with the lowest cost for each. Traffic
for 10.10.10.1 goes to Alteon 1 because its host route has the lowest cost for that address. Traffic
for 10.10.10.2 goes to Alteon 2 because its host route has the lowest cost. This effectively shares
the load among ABRs. Both devices then use standard Server Load Balancing (SLB) to distribute
traffic among available real servers.
In addition, if one of Alteons were to fail, the upstream routing device would forward the traffic to
the ABR whose host route has the next lowest cost. The remaining device assumes the entire load
for both virtual servers.
Figure 24: Host Routes Example
Configuring Host Routes on Alteon 1
1. Configure IP interfaces for each network that is attached to OSPF areas.
2. Configure basic SLB parameters. Alteon 1 is connected to two real servers. Each real server is
given an IP address and is placed in the same real server group.
>> Virtual server 1 # /cfg/l3/if 1
(Select menu for IP interface 1)
>> IP Interface 1 # addr 10.10.10.5
(Set IP address on backbone network)
>> IP Interface 1 # enable
(Enable IP interface 1)
>> IP Interface 1 # /cfg/l3/if 2
(Select menu for IP interface 2)
>> IP Interface 2 # addr 100.100.100.40
(Set IP address on stub area network)
>> IP Interface 2 # enable
(Enable IP interface 2)
