This was actually the first thing I thought of. But then I read the documentation for IO::Socket::INET, which states:

In addition to the key-value pairs accepted by IO::Socket, IO::Socket::INET provides.

PeerAddr     Remote host address          <hostname>[:<port>]
PeerHost     Synonym for PeerAddr
PeerPort     Remote port or service       <service>[(<no>)] | <no>
LocalAddr    Local host bind address      hostname[:port]
LocalHost    Synonym for LocalAddr
LocalPort    Local host bind port         <service>[(<no>)] | <no>
...
[download]

So what is the difference between specifying the host and port as separate options, or using a string like '1.2.3.4:8080' (as in jk2addict's original example] as the argument to LocalAddr?

JJ