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Forwarding Rule Editing View


Use the Forwarding Rule Editing View to select, copy, create, and delete forwarding rules. Three default forwarding rules are provided: switch, forward and cache.

Matching rules are processed in strict top-to-bottom order. Therefore, it is important that rules be configured in the order you want. In general, more specific rules should come before less specific rules. The implicit rule for all policies is Accept all.

To present the Forwarding Rule Editing View, click the Forwarding Rules link in the Policy Configuration section of the Config Tool main menu. The following figure shows an example.

When you click the Create button, the Forwarding Rule Editing View changes to display the Forwarding Rule Name field. In addition:

The following section describes the fields in the Forwarding Rule Editing View.


Performance is extremely sensitive to the following forwarding attributes; use extreme caution in setting these values.


Forwarding Rules
Specifies the list of current forwarding rules. You click a forwarding rule in this field to select it, or to designate it as the one you want the new rule to follow when creating a new rule.
Forwarding Rule Name
Specifies a name you give to a specific new forwarding rule.
Forwarding Option
Available options are: switch, forward, and cache. When you select cache, the first packet is processed and the route lookup and policy are cached in the GIGAswitch/IP Switch Controller after the packet is forwarded. Subsequent packets matching the cached state follow the same decision stored in the cached state. When you select switch, the route lookup is cached and the flow is eligible to use the hardware accelerator.
Encapsulation
Available options are: standard and extended. Standard encapsulation is defined in RFC 1954 Type 2 flow, which uses IP source, destination, and TTL to classify packets. Extended encapsulation is defined in RFC 1954 Type 1 flow, which uses IP source, destination, TTL, ToS, IPproto, TCP/UDP source port, and TCP destination port to classify packets.

[Note] Use extended encapsulation only when it is necessary to apply QoS to an individual application that uses a specified TCP/UDP port pair.


Wait Packets
If a flow is eligible to use a hardware accelerator, this value defines when the hardware accelerator is used. For example, a value of 10 instructs the GIGAswitch/IP Switch Controller/Gateway to wait until at least 10 packets have been forwarded prior to using the hardware accelerator. To achieve better performance, it is best to use a larger number of Wait Packets in an GIGAswitch/IP Switch Controller than in a Gateway. It is recommended that the number of Wait Packets in an GIGAswitch/IP Switch Controller be set at roughly twice the number of Wait Packets in a Gateway.
Refresh Timer
Specifies how often conditions should be rechecked to determine eligibility for use of the hardware accelerator. For example, a value of 20 seconds indicates that, in order to be eligible for using the hardware accelerator, a flow must transmit more than Wait Packets number of packets in at least one 20-second interval. This timer can be incremented in 20-second intervals.
Idle Timer
Specifies the interval between the current time and the last time a packet is forwarded. Once a flow is cached, its state is not be deleted until the value in this field is met. This timer can be incremented in 20-second intervals.
Hold Timer
Specifies the time interval between the first packet of a flow arrives at the GIGAswitch/IP Switch Controller and the current time. Once a flow is cached, its state will not be deleted until the value in this field is satisfied. This timer can be incremented in 10-second intervals.
See also:
QoS Policy Configuration View
Edit Rule for Policy View
Move Rule Within Policy View
QoS Configuration
QoS Configuration Helpful Hints

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