Cntlm Has a Listening Address and a Parent Address
Map a Cntlm configuration to the local application endpoint, the authenticated parent proxy and the account used between them.
Username employee
Domain OFFICE
Proxy proxy.office.example:8080
Listen 127.0.0.1:3128
Gateway no
Replace these values with the corporate account and endpoint. Proxy is Cntlm's authenticated parent. Listen is the endpoint local applications use: http://127.0.0.1:3128 in this example. Pointing the application at the parent instead bypasses the intended delegation to Cntlm.
For NTLMv2, configure Auth NTLMv2 and the corresponding PassNTLMv2 hash. Cntlm's -H mode generates hashes using the intended username/domain; some depend on those identities. Replace the stored value when that password changes.
The hash remains an authentication secret. Protect it and configuration backups rather than sharing it with the application-facing address.
This loopback listener limits the example to local clients. To serve other machines, deliberately choose a reachable bind and matching access policy. Those clients must reach Cntlm's actual listener, not copy a localhost address referring to themselves.