Disabling Unicast Rpf (Cli Procedure) - Dell PowerConnect J-EX4200-24T Software Manual

Dell PowerConnect J-Series Ethernet Switch Complete Software Guide for Junos OS
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Disabling Unicast RPF (CLI Procedure)

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that unicast RPF is enabled only on interfaces on which unicast RPF is
explicitly enabled, so even though unicast RPF is enabled on all interfaces,
this status is not displayed.
Enabling unicast RPF explicitly on all interfaces makes it easier to know
whether unicast RPF is enabled on the switch because every interface
shows the correct status. (Only interfaces on which you explicitly enable
unicast RPF display the flag that indicates that unicast RPF is enabled.)
The drawback to this approach is that if you want to disable unicast RPF,
you must explicitly disable it on every interface. If unicast RPF is enabled
on any interface, it is implicitly enabled on all interfaces.
Example: Configuring Unicast RPF on a J-EX Series Switch on page 900
Verifying Unicast RPF Status on page 935
Disabling Unicast RPF (CLI Procedure) on page 928
Troubleshooting Unicast RPF on page 941
Understanding Unicast RPF for J-EX Series Switches on page 872
Unicast reverse-path forwarding (RPF) can help protect your LAN from denial-of-service
(DoS) and distributed denial-of-service (DDoS) attacks on untrusted interfaces. Unicast
RPF filters traffic with source addresses that do not use the incoming interface as the
best return path back to the source. If the network configuration changes so that an
interface that has unicast RPF enabled becomes a trusted interface or becomes
asymmetrically routed (the interface that receives a packet is not the best return path
to the packet's source), disable unicast RPF.
To disable unicast RPF on a J-EX4200 switch, you must delete it from every interface on
which you explicitly configured it. If you do not disable unicast RPF on every interface on
which you explicitly enabled it, it remains implicitly enabled on all interfaces. If you attempt
to delete unicast RPF from an interface on which it was not explicitly enabled, the message
warning: statement not found
on which you explicitly enabled it, unicast RPF remains implicitly enabled on all interfaces
of the J-EX4200 switch.
On J-EX8200 switches, the switch does not apply unicast RPF to an interface unless you
explicitly enable that interface for unicast RPF.
displays. If you do not disable unicast RPF on every interface