example ipv6 netmask that is not in prefix length form
<p><code>FE80:0000:0000:0000:0202:B3FF:FE1E:8329/128</code> is an IPv6 address with netmask.</p>

<p>For IPv4, the netmask could be given as <code>/24</code> or <code>255.255.255.0</code>, either format.</p>

<p>How can I represent <code>/128</code> that is not a prefix length ?
Like, <code>255.255.255.0</code> is not a prefix length.</p>

<p>One way to verify is to use this site:</p>

<p><a href="https://www.ultratools.com/tools/ipv6CIDRToRangeResult?ipAddress=FE80%3A0000%3A0000%3A0000%3A0202%3AB3FF%3AFE1E%3A8329%2F128" rel="nofollow">https://www.ultratools.com/tools/ipv6CIDRToRangeResult?ipAddress=FE80%3A0000%3A0000%3A0000%3A0202%3AB3FF%3AFE1E%3A8329%2F128</a></p>

<p>It should not give error.</p>