You want to add sites to the bypass list in the Symantec Web Security Service (WSS), or review the list of bypassed sites.
IMPORTANT: Bypassed sites only apply to locations that use the Explicit Proxy and Unified Agent / WSS Agent (v4.4+) access methods to connect to WSS. Symantec Endpoint Protection's (SEP) WSS Traffic Redirection (WTR) is considered an explicit access method. Bypassed sites will not be effective for IPSEC (see notes below on how to bypass traffic for IPSEC connections).
Notes: