Brocade Multi-Service IronWare Routing Configuration Guide (Supporting R05.6.00) - Manual (Page 521)

Multi-Service IronWare Routing Configuration Guide 493
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IPv6 ND Prefix Suppress
IPv6 ND Prefix Suppress
Brocade devices support IPv6 ND Prefix Suppress, which is useful in an LAN where multiple hosts
are connected to router(s). Prefix Suppress performs these functions:
• Advertisement of on-link prefix information is suppressed in router advertisement (RA)
messages.
• Hosts are prevented from auto configuring based on the prefix in the RA message.
• DHCPv6 is used for security and accountability.
• Advertisement of identical prefixes by multiple routers is suppressed.
• Global Suppress option suppresses IPv6 addresses defined on an interface from getting
advertised in the RA message.
NOTE
When the user configures the Global Suppress option, an RA is generated with all
deprecated IPv6 address entries that are not advertised in subsequent RA messages.
• Prefix advertisement entry in the RA message is advertised if a duplicate entry exists in
the prefix advertisement list and IPv6 address list
Configuring the suppress option to specific IPv6 addresses defined on an interface generates
deprecated IPv6 address entries (i.e. with
preferred lifetime = 0 hours
and
valid lifetime
= 2 hours
) in RA messages. When a host receives deprecated IPv6 address entries, the address is
forbidden for new sessions although existing sessions can continue using the address.
Deprecated entries are advertised in the following scenarios:
• Suppress option is configured for IPv6 address entries.
• Prefix advertisement entries are un-configured.
• IPv6 address entries are un-configured.
Configuring IPv6 Prefix Suppress
Command syntax for configuring the suppress option for an IPv6 address entry:
(config-if-x)#[no] ipv6 nd address suppress
Command syntax for configuring the suppress option for all IPv6 address entries:
(config-if-x)#[no] ipv6 nd address suppress
Command syntax for Show IPv6 interface output is modified to display individual or globally
suppressed entries:
Router-A# show ipv6 interface ethernet 1/2
MTU is 1500 bytes
ICMP redirects are disabled
ND DAD is enabled, number of DAD attempts: 3
ND reachable time is 30000 Milliseconds
ND advertised reachable time is 0 seconds
ND retransmit interval is 1000 milliseconds
ND advertised retransmit interval is 0 milliseconds
ND next router advertisement will be sent in 2 seconds