Refreshing Policies
When a policy file is changed (such as adding, deleting an entry,
adding/deleting/modifying a statement), the information in the policy database does not
change until the policy is refreshed. The user must refresh the policy so that the latest
copy of policy is used. When the policy is refreshed, the new policy file is read,
processed, and stored in the server database.
Any
clients that use the policy are updated.
-
To refresh the policy, enter the command:
refresh
policy policy_name
For ACL policies only, during the
time that an ACL policy is refreshed, packets on the interface are blackholed, by default.
This is to protect the switch during the short time that the policy is being applied to
the hardware. It is conceivable that an unwanted packet could be forwarded by the switch
as the new ACL is being set up in the hardware. You can disable this behavior.

Note
Performing a refresh on multiple ports requires the original and
modified policy to coexist at the same time in the intermittent state. If this is not
possible due to slice limitations, the refresh will fail with "ACL slice full"
error.
-
To control the behavior of the switch during an ACL
refresh, enter the commands:
enable access-list refresh
blackhole
disable access-list refresh blackhole
In releases previous to ExtremeXOS 11.4, when ACLs were
refreshed, all the ACL entries were removed, and new ACL entries
were created to implement the newly applied policy.
Beginning in release 11.4, the policy manager uses Smart Refresh to
update the ACLs. When a change is detected, only the ACL changes needed to modify the
ACLs are sent to the hardware, and the unchanged entries remain. This behavior avoids
having to blackhole packets because the ACLs have been momentarily cleared. Smart
Refresh works well up for up to 200 changes. If the number of changes exceeds 200, you
will see this message: Policy file has more than 200 new rules. Smart refresh can not be
carried out. Following this message, you will see a prompt based on the current
blackhole configuration. If blackhole is disabled you will see the following
prompt:
Note, the current setting for Access-list Refresh Blackhole is Disabled. WARNING: If a full refresh is performed, it is possible packets that should be denied may be forwarded through the switch during the time the access list is being installed.
Would you like to perform a full refresh?
If blackhole is enabled, you will see the following prompt:
Note, the current setting for Access-list Refresh Blackhole is Enabled.
Would you like to perform a full refresh?
To take advantage of Smart Refresh, disable access-list
refresh blackholing.

Note
Smart refresh is
not performed for policies if the number of entries in the policy
change during refresh.