Alcatel-Lucent 7750 SR-OS, Руководство по настройке

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ACL Filter Policy Overview
Page 414 7750 SR OS Router Configuration Guide
Figure 16: IOM/CPM Filter Policy Using an Address Prefix Match List
Note: The hardware resource usage does not change whether filter match lists are used or whether
operator creates multiple entries (each per one element of the list): however, a careful
consideration must be given to how the lists are used to ensure only desired match permutations
are created in a filter policy entry (especially when other matching criteria that are also lists or
ranges are specified in the same entry). The system verifies that a new list element, for example, an
IP address prefix, cannot be added to a given list or a list cannot be used by a new filter policy
unless resources exist in hardware to implement the required filter policy (ies) that reference that
list. If that is not the case, addition of a new element to the list or use of the list by another policy
will fail.
Some use cases like those driven by dynamic policy changes, may result in acceptance of filter
policy configuration changes that cannot be programmed in hardware because of the resource
exhaustion. If that is the case, when attempting to program a filter entry that uses a match list(s),
the operation will fail, the entry will be not programmed, and a notification of that failure will be
provided to an operator.
Please refer to SROS Release Notes for what objects can be grouped into a filter match list for
IOM and CPM filter policies.
Auto-generation of Filter-policy Address Prefix Match Lists
It is often desired to automatically update a filter policy when the configuration on a router
changes. To allow such a touch-less filter policy management, SROS allows auto-generation of
address prefixes for IPv4 or IPv6 address prefix match lists based on operator-configured criteria.
When the configuration on a router changes, the match lists address prefixes are automatically
updated and, in-turn, all filter policies (CPM or IOM) that use these match lists are automatically
updated.
Entry K
match: IPv4 Prefix List A
CPM Filter
IOM Filters
OSSG730
Entry M
match: IPv4 Prefix List A
IPv4 Prefix 1
IPv4 Prefix 2
IPv4 Prefix N
IPv4 Prefix List A