EvidenceSheet

A.8.21 Security of network services

Identify, implement and monitor security mechanisms and service levels for network services.

18
artefacts
4
held by a system
6
at each review
hard
to go live
Policy repository / GRC workspace
where the evidence lives
teal = a system already holds it · olive = produced at each review

system holds itEvidence a system already holds

  • Exported firewall rule sets with change timestamps · Cloud console / configuration management
  • IDS/IPS configuration snapshots · Cloud console / configuration management
  • VPN tunnel configuration files and encryption parameters · Cloud console / configuration management
  • Incident response tickets generated from network alerts · SIEM / log platform

periodic reviewEvidence produced at each review

  • Asset tagging records linking services to responsible owners · Cloud console / configuration management
  • Alerting dashboard screenshots highlighting critical events · SIEM / log platform
  • Signed SLA contracts with cloud and telecom providers · Vendor register / contract repository
  • Quarterly SLA performance reports · Vendor register / contract repository
  • Records of penalties or compensation applied for SLA breaches · Vendor register / contract repository
  • Post‑implementation review reports documenting outcomes · Ticketing / ITSM

governing documentDocuments that govern the control

  • Network Service Register showing all internal and external services · Policy repository / GRC workspace
  • Topology diagram mapping services to network segments · Policy repository / GRC workspace
  • Secure protocol usage policy document · Policy repository / GRC workspace
  • Centralised syslog archives for routers, switches and firewalls · Policy repository / GRC workspace
  • Network traffic analysis reports for the last quarter · Policy repository / GRC workspace
  • Submitted change request forms for network service modifications · Policy repository / GRC workspace
  • Approved implementation plans with risk assessments · Policy repository / GRC workspace
  • Rollback procedure documentation for critical services · Policy repository / GRC workspace

First move

Mostly documents and reviews. Pull the 4 system-held artefacts from your Cloud console / configuration management on a schedule; put the documents under version control with an owner and review date, and log each review as a dated record with a named reviewer.

Common gaps auditors find

Do this for your whole sheet

Paste the rows you run your controls from and get this mapping for every control at once, with the periodic-review ones flagged and a first move per row. No account for the first run.

Build my evidence sheet

A.8.20 Networks security · A.8.22 Segregation of networks