Protected traffic is tunneled through the Symantec Web Security Service (WSS). You want to know which IP addresses traffic from WSS comes from.
The egress IP address seen by web servers is no longer the egress IP address of your own network.
The egress and ingress IP addresses are now consolidated into a single article. Please see https://knowledge.broadcom.com/external/article/167174/web-security-service-wss-ingress-and-egr.html for the list of all the ingress and egress IP addresses.