caddyserver/caddy · error

invalid IP address: '%s': %v

Error message

invalid IP address: '%s': %v

What it means

Error "invalid IP address: '%s': %v" thrown in caddyserver/caddy.

Source

Thrown at modules/caddytls/matchers.go:382

		}
		return false
	}
	return (len(m.cidrs) == 0 || m.matches(ipAddr, m.cidrs)) &&
		(len(m.notCidrs) == 0 || !m.matches(ipAddr, m.notCidrs))
}

func (MatchRemoteIP) parseIPRange(str string) ([]netip.Prefix, error) {
	var cidrs []netip.Prefix
	if strings.Contains(str, "/") {
		ipNet, err := netip.ParsePrefix(str)
		if err != nil {
			return nil, fmt.Errorf("parsing CIDR expression: %v", err)
		}
		cidrs = append(cidrs, ipNet)
	} else {
		ipAddr, err := netip.ParseAddr(str)
		if err != nil {
			return nil, fmt.Errorf("invalid IP address: '%s': %v", str, err)
		}
		ip := netip.PrefixFrom(ipAddr, ipAddr.BitLen())
		cidrs = append(cidrs, ip)
	}
	return cidrs, nil
}

func (MatchRemoteIP) matches(ip netip.Addr, ranges []netip.Prefix) bool {
	return slices.ContainsFunc(ranges, func(prefix netip.Prefix) bool {
		return prefix.Contains(ip)
	})
}

// UnmarshalCaddyfile sets up the MatchRemoteIP from Caddyfile tokens. Syntax:
//
//	remote_ip <ranges...>
//
// Note: IPs and CIDRs prefixed with ! symbol are treated as not_ranges

View on GitHub (pinned to 50e54ee279)

Solutions

1. Correct the IP address in the configuration; it must be a valid IPv4 or IPv6 address.

When it happens

Trigger: Thrown at modules/caddytls/matchers.go:382 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/a7fe6345b5450706. Report an issue: GitHub.