Balancing Loads Over Connections To Different Neighbors - HP 7102dl - ProCurve Secure Router Configuration Manual

IP Routing—Configuring RIP, OSPF, BGP, and PBR
Configuring BGP
N o t e s
15-78
Your must inform your ISP if you are using a loopback interface as the update
source so that its IT staff can correctly configure the ISP router to connect to
your router.
When you use a loopback interface as the update source, you add a hop
between neighbors. (See Figure 15-16.) You must enable the multihop func-
tion:
Syntax: ebgp-multihop <hop count>
The hop count can be between 1 and 254.
For example, enter the following commands:
ProCurve(config)# interface loopback 1
ProCurve(config-loopback 1)# ip address 2.2.2.2 /32
ProCurve(config-loopback 1)# exit
ProCurve(config)# router bgp 1
ProCurve(config-bgp)# neighbor 1.1.1.1
ProCurve(config-bgp-neighbor)# update-source loopback 1
ProCurve(config-bgp-neighbor)# ebgp-multihop 2
Load balancing inbound traffic is more difficult. In many ways, it is up to the
ISP to decide through which connection to route traffic.

Balancing Loads over Connections to Different Neighbors

You may connect to multiple ISP routers through two or more interfaces on
the same router or on different routers. These instructions contain general
guidelines for load balancing over both types of connections.
For example, Router A and B both connect to an ISP. (See Figure 15-17.) Your
organization does not want to pay for two Internet connections, only to have
one underused. You cannot directly configure load balancing, nor manually
force the routers to send certain traffic over one link and other traffic over the
other. BGP uses a set algorithm to select routes.
However, you can attempt to manipulate BGP so that each local and ISP router
selects best routes that balance traffic across both links.
Balancing Outbound Traffic. In this situation, the BGP route-selection
algorithm automatically balances outbound traffic.