firewalld / iptables Consulting & Hardening

Firewalls are the first line of defense on Linux. Zwiegnet provides expert design, implementation, optimization, and troubleshooting of firewalld (preferred on modern distros) and legacy iptables — including seamless migration to nftables for better performance and future-proofing.

Our firewall services include:

• firewalld Zone & Rule Design – Custom zones (public, internal, dmz, trusted), rich rules, services/ports, and source-based access control.
• iptables / nftables Advanced Configuration – Complex chains, mangle table, NAT (SNAT/DNAT), connection tracking, and performance-optimized rulesets.
• Migration iptables → nftables / firewalld – Smooth transition from legacy iptables to modern nftables or firewalld with rule validation and minimal downtime.
• Logging & Monitoring – Auditd integration, ulogd, firewalld rich logging, and centralized logging (rsyslog → SIEM) for compliance and forensics.
• Security Hardening – Rate limiting, anti-spoofing, DDoS mitigation, fail2ban integration, and compliance with PCI-DSS, HIPAA, NIST standards.
• High Availability & Clustering – Sync rules across nodes with keepalived/VRRP, conntrackd for stateful failover, and multi-node firewall setups.
• Performance Tuning – Optimize for high-throughput environments, conntrack tuning, rule ordering, and benchmarking (iperf, stress testing).
• Troubleshooting & Recovery – Diagnose blocked traffic, NAT issues, state table overflows, and rapid rule rollback/recovery.

Ideal for: enterprises, financial institutions, healthcare providers, e-commerce, SaaS platforms, and any organization requiring robust, high-performance, and compliant Linux firewall protection.

Located between Madison and Milwaukee, Wisconsin since 2009 — direct access to Linux firewall specialists with deep experience in firewalld, iptables, and nftables.