SNMP Counters Have Their Own Squid Access Rules

Authorize Squid's monitoring interface at snmp_access rather than adding an HTTP request permission.

The monitoring host can reach Squid, and an allow rule names its community. SNMP queries still fail. Check which access directive consumes that ACL.

http_access evaluates HTTP proxy requests. It does not authorize the SNMP agent. Squid versions providing the agent use snmp_access for that separate decision.

acl monitor_host src 192.0.2.44/32
acl monitor_community snmp_community approved_monitor
snmp_access allow monitor_host monitor_community
snmp_access deny all

This is a monitoring-authorization excerpt, not a complete agent setup. The build must include SNMP support, the deployed release must provide the feature, and its agent port and network access must be configured.

A configuration GUI can create a syntactically valid rule in the wrong section. Read the generated directive rather than relying on the ACL's friendly name. An object called “SNMP community” does not make every place it is referenced an SNMP permission.

Keep the monitoring source restricted. A successful HTTP proxy request and an accepted SNMP query answer different questions, even when they reach the same machine.

Artiglyn mynjee