}

nextTest:
	for i, testCase := range testCases {
		listener, errs := newHTTPListener(context.Background(),
			testCase.serverAddrs,
			TCPOptions{},
		)
		for _, err := range errs {
			if err != nil {
				if strings.Contains(err.Error(), "The requested address is not valid in its context") {
					// Ignore if IP is unbindable.
					continue nextTest
				}

	dups := make(map[string][]string)
	for name, addr := range want {
		if _, ok := dups[addr]; !ok {
			dups[addr] = make([]string, 0)
		}
		dups[addr] = append(dups[addr], name)
	}

nextWant:
	for name, wantAddr := range want {
		if haveAddr, ok := have[name]; ok {
			if haveAddr != wantAddr {
				t.Errorf("unexpected MAC address for %q - %v, want %v", name, haveAddr, wantAddr)
			}
			continue