Why does deploying LTM into an existing network immediately improve security?

LTM does not restrict traffic to specific ports by default; port-based filtering depends entirely on the virtual server configuration the administrator creates.

LTM does not automatically inspect all traffic for DDoS attacks; that capability requires the Advanced Firewall Manager module or explicit profile configuration.

BIG-IP LTM operates as a full proxy with a whitelist-based default model in which no traffic passes to backend resources until an administrator explicitly defines virtual servers, pools, and associated policies. Any traffic that does not match a configured virtual server is silently dropped, immediately reducing the attack surface when LTM is inserted into an existing network. This default-deny behavior requires zero additional configuration to take effect.

LTM does not enforce user authentication before allowing application access by default; authentication requires explicit Access Policy Manager configuration.

LTM does not limit resource access to LAN administrators; access control is governed by virtual server definitions and policies, not by administrator role.