An undefined event
is triggered when the NetScaler cannot evaluate a policy, usually because it
detects a logical or other error in the policy or an error condition on the
NetScaler. When the rewrite policy evaluation results in an error, the
specified undefined action is carried out. Undefined actions configured at the
rewrite policy level are carried out before a globally configured undefined
supports following three types of undefined actions:
rewrite processing, but does not alter the packet flow. This means that the
NetScaler continues to process requests and responses that do not match any
rewrite policy, and eventually forwards them to the requested URL unless
another feature intervenes and blocks or redirects the request. This action is
appropriate for normal requests to your Web servers, and is the default
- Resets the
client connection. This means that the NetScaler tells the client that it must
re-establish its session with the Web server. This action is appropriate for
repeat requests for Web pages that do not exist, or for connections that might
be attempts to hack or probe your protected Web site(s).
drops the request without responding to the client in any way. This means that
the NetScaler simply discards the connection without responding to the client.
This action is appropriate for requests that appear to be part of a DDoS attack
or another sustained attack on your servers.
events can be triggered for both request and response flow specific policies.