netbirdio/netbird · error

create chain %s: %w

Error message

create chain %s: %w

What it means

Error "create chain %s: %w" thrown in netbirdio/netbird.

Source

Thrown at client/firewall/iptables/router_linux.go:1054

	}

	r.updateState()
	return nil
}

// ensureNATOutputChain lazily creates the OUTPUT NAT chain and jump rule on first use.
func (r *router) ensureNATOutputChain() error {
	if _, exists := r.rules[jumpNatOutput]; exists {
		return nil
	}

	chainExists, err := r.iptablesClient.ChainExists(tableNat, chainNATOutput)
	if err != nil {
		return fmt.Errorf("check chain %s: %w", chainNATOutput, err)
	}
	if !chainExists {
		if err := r.iptablesClient.NewChain(tableNat, chainNATOutput); err != nil {
			return fmt.Errorf("create chain %s: %w", chainNATOutput, err)
		}
	}

	jumpRule := []string{"-j", chainNATOutput}
	if err := r.iptablesClient.Insert(tableNat, "OUTPUT", 1, jumpRule...); err != nil {
		if !chainExists {
			if delErr := r.iptablesClient.ClearAndDeleteChain(tableNat, chainNATOutput); delErr != nil {
				log.Warnf("failed to rollback chain %s: %v", chainNATOutput, delErr)
			}
		}
		return fmt.Errorf("add OUTPUT jump rule: %w", err)
	}
	r.rules[jumpNatOutput] = jumpRule

	r.updateState()
	return nil
}

View on GitHub (pinned to 93e97f4bf1)

When it happens

Trigger: Thrown at client/firewall/iptables/router_linux.go:1054 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of netbirdio/netbird@93e97f4bf1 (2026-08-16). Data as JSON: /api/errors/3797d0be0d606ca0. Report an issue: GitHub.