Handbook
N8406-023 1Gb Intelligent L3 Switch Application Guide 117
3. Enable OSPF authentication for Area 2 on switch 4.
>> # /cfg/l3/ospf/aindex 2/auth password
4. Configure a simple text password up to eight characters for the virtual link between Area 2 and Area 0 on
switches 2 and 4.
>> # /cfg/l3/ospf/virt 1/key alteon
Use the following commands to configure MD5 authentication on the switches shown in the figure:
5. Enable OSPF MD5 authentication for Area 0 on switches 1, 2, and 3
>> # /cfg/l3/ospf/aindex 0/auth md5
6. Configure MD5 key ID for Area 0 on switches 1, 2, and 3.
>> # /cfg/l3/ospf/md5key 1/key test
7. Assign MD5 key ID to OSPF interfaces on switches 1, 2, and 3.
>> # /cfg/l3/ospf/if 1
>> OSPF Interface 1 # mdkey 1
>> OSPF Interface 1 # ../if 2
>> OSPF Interface 2 # mdkey 1
>> OSPF Interface 1 # ../if 3
>> OSPF Interface 3 # mdkey 1
8. Enable OSPF MD5 authentication for Area 2 on switch 4.
>> # /cfg/l3/ospf/aindex 2/auth md5
9. Configure MD5 key for the virtual link between Area 2 and Area 0 on switches 2 and 4.
>> # /cfg/l3/ospf/md5key 2/key alteon
10. Assign MD5 key ID to OSPF virtual link on switches 2 and 4.
>> # /cfg/l3/ospf/virt 1/mdkey 2
Host routes for load balancing
The switch implementation of OSPF includes host routes. Host routes are used for advertising network device IP
addresses to external networks, accomplishing the following goals:
ABR Load Sharing
As a form of load balancing, host routes can be used for dividing OSPF traffic among multiple ABRs. To
accomplish this, each switch provides identical services but advertises a host route for a different IP address
to the external network. If each IP address serves a different and equal portion of the external world, incoming
traffic from the upstream router should be split evenly among ABRs.
ABR Failover
Complementing ABR load sharing, identical host routes can be configured on each ABR. These host routes
can be given different costs so that a different ABR is selected as the preferred route for each server and the
others are available as backups for failover purposes.
If redundant routes via multiple routing processes (such as OSPF, RIP, or static routes) exist on your network, the
switch defaults to the OSPF-derived route.