F3726, F3211, F3174, R5135, R3816-HP Firewalls and UTM Devices High Availability Configuration Guide-6PW100

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• Logical links—Physical link-based logical entities to process services.
• Virtual service—A logical entity. A virtual service can correspond to multiple logical links.
Outbound link load balancing operates in the following way:
1. After a user sends a request to the destination segment specified by the virtual service of the LB
device, if a persistence method is specified in the virtual service, and matched persistence entries
exist, the request is distributed according to the persistence entries. Otherwise, the following step
is performed. See
635H5 for the introduction to the persistence method.
2. The virtual service obtains the information of the corresponding logical link group and matches the
ACLs specified in the logical links one by one based on the logical link weights from high to low.
For the packets allowed by ACL, the virtual service distributes the packets to the corresponding
logical links; for the logical links that are denied by ACL or no matched logical links are found, the
LB device goes to the following step.
3. If best performing link is enabled in the virtual service, a best link is selected based on the matched
best performing link entry. If no match is found, best performing link detection is performed to
generate a best performing link entry, and the LB device goes to the following step.
4. If Internet Service Provider (ISP) routing is enabled for a virtual service, a best link is selected based
on the matched ISP entry. If no match is found, the following step is performed.
5. The virtual service distributes the packets to a logical link (corresponding to a unique physical link)
according to the link scheduling algorithm configured in the logical link group.
When the link busy protection function is enabled, if there is an idle link, best-performing link, ISP routing,
and algorithm scheduling do not take effect on busy links.
If a logical link is configured with the stop scheduling function, best-performing link, ISP routing, and
algorithm scheduling do not take effect on the logical link.
201BRecommended configuration procedure
Ste
p
Remarks
11. Saving of the last hop
information
Optional.
For more information, see "
636H
Configuring public parameters."
12. Enabling unidirectional traffic
detection
Optional.
For more information, see "
637H
Configuring public parameters."
IMPORTANT:
Support for this function depends on the device model.
13. 638HConfiguring a health monitoring
method
Optional.
14. 639HCreating a physical link Required.
15. 640HConfiguring the best performing
link function
Optional.
Configure dynamic best performing link parameters and static best
performing link entries.
For outbound link load balancing, this function is available only when
enabling of best performing link is configured for a virtual service.