Batfish vs Invariant

Batfish is an open-source tool for analyzing network device configurations and validating network behavior. It works from configuration files, so core analysis does not require direct access to network devices. Teams can inspect deployed configurations and check planned changes before deployment. Checks cover undefined references, MTU and AAA settings, template compliance, sensitive-service reachability and expected traffic paths. Batfish can test whether end-to-end reachability survives any single-link or single-device failure, compare current and planned reachability, assess ACL or firewall changes and evaluate functional equivalence across vendors. Pybatfish provides a Python 3 SDK, and example Jupyter notebooks are available. An all-in-one Docker container bundles Batfish and notebooks. It runs on operating systems supporting Docker. Documented support includes Arista, AWS, Azure, Cisco, Juniper, Palo Alto Networks and SONiC, while Aruba, Dell Force10 and Foundry have limited support.

Invariant validates network configurations against connectivity and security rules in a cross-vendor digital twin. It builds the model from configuration files, so direct access to routers or switches is not required. Users define policies in YAML and evaluate them against network snapshots, including proposed changes before deployment. Results can report policy violations and failures affecting critical flows. Scheduled network scans can trigger incident alerts with virtual traceroutes and virtual route-table differences. The service lists Cisco, Juniper, Palo Alto, and AWS among supported vendors, and integrations including Jenkins, GitHub Actions, LibreNMS, Netmiko, Aerleon, Capirca, IPAM, and SIEM workflows. A CLI, SDK, and API support automation. Listed protocols include BGP, OSPF, IPSec, NAT, policy-based routing, VPN, ACL, and VLAN. Invariant offers hybrid deployment and web/API access. The Basic account is free, billed as a free Basic account with effectively no usage limits. Higher tiers add SSO, larger device counts, and preview features.