RootCAs:                  rootCAs,
			PreferServerCipherSuites: true,
			MinVersion:               tls.VersionTLS12,
			NextProtos:               []string{"http/1.1", "h2"},
			ClientSessionCache:       tls.NewLRUClientSessionCache(64),
			CipherSuites:             crypto.TLSCiphersBackwardCompatible(),
			CurvePreferences:         crypto.TLSCurveIDs(),
		}
		// This is only to support client side certificate authentication

	}

	tlsClientConfig := tls.Config{
		RootCAs:            s.RootCAs,
		CipherSuites:       s.CipherSuites,
		CurvePreferences:   s.CurvePreferences,
		ClientSessionCache: tls.NewLRUClientSessionCache(tlsClientSessionCacheSize),
	}

	// For more details about various values used here refer
	// https://golang.org/pkg/net/http/#Transport documentation
	tr := &http.Transport{

		SRVRecordName: getCfgVal(SRVRecordName),
		TLS: &tls.Config{
			ServerName:         host,
			MinVersion:         tls.VersionTLS12,
			NextProtos:         []string{"h2", "http/1.1"},
			ClientSessionCache: tls.NewLRUClientSessionCache(100),
			CipherSuites:       crypto.TLSCiphersBackwardCompatible(), // Contains RSA key exchange
			RootCAs:            rootCAs,
		},
	}

	// Parse explicitly set enable=on/off flag.