I have stumbled upon a interesting problem in our application. When testing our app in a Linux VM that is unable to get a IPv4 address, LWP fails to connect to localhost. This app has the webserver running and Firefox is able to connect to it fine.

The VM: Stock CentOS 6.4 Desktop in Virtual Box on Corporate Win 7 with the following network adapters:

When I bring up a network that has a IPv4 connection, it magically starts working. I take it down and LWP stops working. However, Firefox happily works anyways. Then when I take down all eth interfaces, it works again.

Here is the boiled down test script:

#!perl -w
use strict;
use LWP;

my $browser = LWP::UserAgent->new();
my $response = $browser->get("http://localhost:8080/index.html");
if($response->is_success()) {
  print "Success\n";
} else {
  print "Failure\n";
}
print "Response: ".$response->as_string();

[download]
We have had a few people look into this and it has us stumped. All the system tools for networking still work for us.

In reply to LWP connecting to LWP issue when no eth has ipv4 address by admiral_grinder

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