Alcatel-Lucent 7750 SR-OS, Руководство по настройке

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Hybrid OpenFlow Switching
Page 584 7750 SR OS Router Configuration Guide
When an LSP in the H-OFS logical port table goes down, the OF Switch removes the LSP from its
logical port table and may notify the controller of that fact if the logical port status reporting is
enabled. It is up to the OF controller to decide whether to remove rules using this LSP or not. If the
rules are left in the flow table, the traffic that was to be redirected to this LSP will instead be
subject to a forward action for this flow rule. Note that if the controller does not remove the entries
and the system re-uses the LSP identified for another LSP, the rules left in the flow table will start
redirecting traffic onto this new LSP.
In some deployments, an SDN controller may need to learn from the router H-OFS logical ports
status. To support that function, the OF switch supports optional status reporting using
asynchronous OF protocol messages for ports status change.
Forward action
An OF controller can program forward action, when a specific flow is to be forwarded using
regular router forwarding. Note that this would be a default behavior if the filter-policy embedding
this OF switch instance has a default-action forward and no filter policy rule matches the flow. To
implement forward action, the following OF encoding is used
f
low_mod: instruction=write_action, action=output_port, port=NORMAL
, where:
-
NORMAL
is a OF reserved value.
Drop action
An OF controller can program a drop action, when packets of a specific flow are to be dropped. To
implement drop action, the following OF encoding is used:
• A wildcard rule with empty action-set