What are some of the best practices for APM CE (CEM) Web Server Filters?

Document ID : KB000048068
Last Modified Date : 14/02/2018
Show Technical Document Details


This provides a rough framework to follow when implementing web server filters.


Here are some guidelines to follow when creating web server filters.

  • Always let your span/tap/aggregator do the filtering if possible. This will reduce the load on the TIM.
  • An important step is determining where the TIM is placed and which IP Addresses are visible to the customer:

    • If the TIM is before the firewall/load balancer and If a firewall/load balancer is in front of a web server, then use the IP address of the firewall(s)/load balancer(s).
    • If the TIM is after the firewall/load balancer or there is no firewall/load balancer, then use the web server(s) IP address(es).

  • Keep a snapshot of the web server filter current settings
  • To minimize traffic, make multiple filters of the same IP addresses to limit web server traffic to specific ports rather than setting to Port 0 (all traffic) in one filter.
  • Use the IP address that the customer sees from their web browser which is typically the virtual rather than the physical IP address.