3Com MSR 50 Series Configuration Manual page 732

732 C 50: IP 6 U
HAPTER V NICAST
P R C
OLICY OUTING ONFIGURATION
There are six types of apply clauses: apply ipv6-precedence, apply
output-interface, apply ipv6-address next-hop, apply default
output-interface, apply ipv6-address default next-hop, and apply
destination-based-forwarding. You can specify only one apply clause for each
type in a policy. In the case that a packet satisfies all if-match clauses on a node,
the priorities of these types of apply clauses are ranked as follows:
apply ipv6-precedence: If configured, this clause will always be executed.
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apply output-interface and apply ipv6-address next-hop: The apply
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output-interface clause takes precedence over the apply ipv6-address
next-hop clause. This means that only the apply output-interface clause will
be executed when both are configured.
apply default output-interface and apply ipv6-address default next-hop:
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Alike, the apply default output-interface clause takes precedence over the
apply ipv6-address default next-hop clause. This means that only the apply
default output-interface clause is executed when both are configured. Either
of these two clauses is executed only when neither outgoing interface nor next
hop is available for the packets, and the destination address does not have a
corresponding route in the routing table.
apply destination-based-forwarding: Enables IPv6 destination based
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forwarding. If this clause is configured, denied packets can still be forwarded
through matching a route in the routing table. If not, denied packets are
discarded.
There is an AND relationship between if-match clauses on a node. That is to say, a
packet must satisfy all matching rules specified by all if match clauses for the
node before the action specified by the apply clause is taken. There is an OR
relationship between nodes of a policy. That is, if a packet matches a node, it
passes the policy.
When configuring policy nodes, you need to specify the match mode as permit or
deny:
permit: Specifies the match mode as permit for a policy node. If a packet
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satisfies all rules defined by if-match clauses on the policy node, the apply
clauses are executed. If not, the packet will go to the next policy node for a
match.
deny: Specifies the match mode as deny for a policy node. When a packet
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satisfies all rules defined by if-match clauses on the policy node, the packet
will be denied and will not go to the next policy node for a match.
A packet satisfying the match rules on a node of a policy will not go to the other
nodes. If the packet does not satisfy the match rules of all nodes of the policy, the
packet cannot pass the policy and will be forwarded through the routing table.
You can define five next hops or five outgoing interfaces at most for an IPv6 policy,
implementing load balancing based on data steams.
Follow theses steps to define an IPv6 policy: