'Verify connnectivity between virtual host and virtual-physical \'external\' host'

def testExternalPing(self):

    p = pexpect.spawn(('python    -m    mininet.examples.hwintf    %s' % self.n0.intf()))
    p.expect(self.prompt)
    expectStr = '(\\d+)    packets    transmitted,    (\\d+)    received'
    m = re.search(expectStr, self.h3.cmd('ping    -v    -c    1    10.0.0.1'))
    tx = m.group(1)
    rx = m.group(2)
    self.assertEqual(tx, rx)
    p.sendline('h1    ping    -c    1    10.0.0.3')
    p.expect(expectStr)
    tx = p.match.group(1)
    rx = p.match.group(2)
    self.assertEqual(tx, rx)
    p.expect(self.prompt)
    p.sendline('exit')
    p.wait()
