Configuration Restrictions And Guidelines - HP MSR Series Configuration Manual

When the amount of traffic on the primary interface decreases below the lower threshold, the
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backup interfaces are deactivated in ascending order of priority. This action continues until the
amount of traffic exceeds the lower threshold.
• When the primary interface fails (in DOWN state), the strict active/standby mode applies. Only
one backup interface can forward traffic.
The upper and lower thresholds are user configurable.
NOTE:
"Traffic" on an interface refers to the amount of incoming or outgoing traffic, whichever is higher.
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If two backup interfaces have the same priority, the one configured first has preference.
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As shown in
2/0/2 (with a priority of 30) and GigabitEthernet 2/0/3 (with a priority of 20) are its backup interfaces.
When the amount of traffic on GigabitEthernet 2/0/1 exceeds the upper threshold,
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GigabitEthernet 2/0/2 is activated, because it has higher priority than GigabitEthernet 2/0/3. If
the amount of traffic on GigabitEthernet 2/0/1 still exceeds the upper threshold, GigabitEthernet
2/0/3 is activated.
When the amount of traffic on GigabitEthernet 2/0/1 decreases below the lower threshold,
•
GigabitEthernet 2/0/3 is first deactivated, because its priority is lower than GigabitEthernet
2/0/2. If the amount of traffic on GigabitEthernet 2/0/1 is still below the lower threshold,
GigabitEthernet 2/0/2 is deactivated.
Figure 2 Load sharing mode

Configuration restrictions and guidelines

When you configure interface backup, follow these restrictions and guidelines:
The device supports up to 10 primary interfaces.
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An interface can be configured as a backup only for one interface.
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An interface cannot be both a primary and backup interface.
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For correct traffic forwarding, make sure the primary and backup interfaces have routes to the
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destination network.
Figure 2, GigabitEthernet 2/0/1 on Router A is the primary interface. GigabitEthernet
3