owasp-amass/amass · error

is not a valid IP address or range

Error message

%s is not a valid IP address or range

What it means

Set parses each whitespace/comma-separated token in an amass scope input as either an IP range (via parseRange) or a single IP (via net.ParseIP). If a token fails both, this error is returned naming the offending token. It indicates malformed scope input that is neither a CIDR-compatible range nor a valid IP literal.

Solutions

1. Check the named token in your scope input and fix the typo or remove the invalid entry
2. Use only valid IP literals or 'start-end' ranges in IP scope entries; use the domains section for hostnames
3. Validate tokens with net.ParseIP or a tool like `ipcalc` before adding them to the scope

Example fix

// before
scope.Set("10.0.0.1, example.com")
// after
scope.Set("10.0.0.1") // IPs and ranges only; hostnames belong in the domains scope

for _, ip := range strings.FieldsFunc(input, func(r rune) bool { return r == ',' || r == ' ' || r == '\t' || r == '\n' }) {
	if strings.Count(ip, "-") == 0 && net.ParseIP(ip) == nil {
		return fmt.Errorf("invalid scope entry: %q", ip)
	}
}

func isValidIPToken(s string) bool { return net.ParseIP(s) != nil }

if err := scope.Set(input); err != nil {
	var bad string
	if _, err2 := fmt.Sscanf(err.Error(), "%s is not a valid IP address or range", &bad); err2 == nil {
		log.Printf("removing invalid scope token %q", bad)
	}
}

When it happens

Trigger: Calling Config.Set (or the scope population path that calls it) with a token that parseRange rejects and net.ParseIP cannot parse, e.g. '10.0.0.256', 'not-an-ip', '10.0.0.1-abc', or a stray hostname in an IP scope list.

Common situations: Hand-edited scope config files with typos, pasting domain names into an IP scope, IPv6 shorthand mistakes, or copy-paste artifacts like trailing punctuation.

Understand the failure class

Background: "Invalid value" and "allowed values are" config errors: what your library rejected and how to fix it — this error's family across 41 libraries.

Related errors

• is not a valid IP
• invalid IP address in resolvers file
• invalid key delimiter
• is not a valid IP range
• active enumeration cannot be performed without DNS…

AI-assisted analysis of owasp-amass/amass@79299dce87 (2026-09-06). Data as JSON: /api/errors/c2739417d204a944. Report an issue: GitHub.

Appendix: source

Thrown at config/scope.go:356

	return strings.Join(ipaddrs, ",")
}

// Set implements the flag.Value interface.
func (p *ParseIPs) Set(s string) error {
	if s == "" {
		return fmt.Errorf("IP address parsing failed")
	}

	ips := strings.Split(s, ",")
	for _, ip := range ips {
		// Is this an IP range?
		err := p.parseRange(ip)
		if err == nil {
			continue
		}
		addr := net.ParseIP(ip)
		if addr == nil {
			return fmt.Errorf("%s is not a valid IP address or range", ip)
		}
		*p = append(*p, addr)
	}
	return nil
}

func (p *ParseIPs) appendIPs(addrs []net.IP) error {
	for _, addr := range addrs {
		*p = append(*p, addr)
	}
	return nil
}

func (p *ParseIPs) parseRange(s string) error {
	twoIPs := strings.Split(s, "-")

	// If s is not a range, try parsing it as a single IP
	if twoIPs[0] == s {

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