The Layer 4 Redirect Logging feature allows ISG to capture records of the creation and deletion events for Layer 4 redirect
translation entries. These records can identify users who have applications that do not react to HTTP redirect.
The ISG router acts as an exporter of the Layer 4 redirect logging information, sending a UDP packet periodically to the
configured external collector. The packet contains all of the Layer 4 redirect logging records, in the NetFlow version 9 export
format, for IPv4, IPv6, and dual-stack sessions. The ISG router tracks every creation and deletion event for Layer 4 redirect
translation entries on the router. A packet containing the logging records is generated and sent to the external collector
after the first of one of the following events occurs:
A predefined amount of Layer 4 redirect logging data has accumulated in the local buffer.
A predefined amount of time has passed without the router sending any data records to the collector, and there are data records
in the local buffer to be sent.
If more than one type of logging feature is configured on the same router (for example, network address translation (NAT)
or Firewall), the number of events that can be generated at one time is shared among all of the logging features. Logging
requests are served on a first-come first-serve basis.
Any external collector that supports the NetFlow version 9 or IP information export (IPFIX) protocol can be used to process
Layer 4 redirect logging data exported by the ISG router.