Host routes for load balancing – HP 445946-001 User Manual

Page 140

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OSPF

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Use the following commands to configure MD5 authentication on the switches shown in the figure:

1.

Enable OSPF MD5 authentication for Area 0 on switches 1, 2, and 3

>> # /cfg/l3/ospf/aindex 0/auth md5

2.

Configure MD5 key ID for Area 0 on switches 1, 2, and 3.

>> # /cfg/l3/ospf/md5key 1/key test

3.

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

4.

Enable OSPF MD5 authentication for Area 2 on switch 4.

>> # /cfg/l3/ospf/aindex 2/auth md5

5.

Configure MD5 key for the virtual link between Area 2 and Area 0 on switches 2 and 4.

>> # /cfg/l3/ospf/md5key 2/key packard

6.

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 HP 10GbE 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.

Equal Cost Multipath (ECMP)
With equal cost multipath, a router potentially has several available next hops towards any given

destination. ECMP allows separate routes to be calculated for each IP Type of Service. All paths of
equal cost to a given destination are calculated, and the next hops for all equal-cost paths are

inserted into the routing table.

If redundant routes via multiple routing processes (such as OSPF, RIP, BGP, or static routes) exist on your

network, the switch defaults to the OSPF-derived route.

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