Required ports: UDP port 1701, UDP 500 and ESP for IKE, UDP 500 and 4500 for NAT-T; Transport and authentication protocols: L2TP (Layer 2 Tunneling Protocol) IPSec (Internet Protocol Security) IKE (Internet Key Exchange) ESP (Encapsulating Security Payload) Authentication: MD5, SHA-1, SHA2-256, SHA2-384, SHA2-512

本項ではTCPやUDPにおけるポート番号の一覧を示す。. コンピュータネットワークにおいて、インターネット・プロトコル・スイートのトランスポート層にあたるTransmission Control Protocol (TCP) やUser Datagram Protocol (UDP) では、他のプロトコル同様、ホスト間通信のエンドポイントを指定する際に数字の port 1701/tcp (L2TP) port 1194/udp (OpenVPN) QNAP NAS uses port 1723/TCP for PPTP VPN. It can also use 1194/UDP (OpenVPN), and a number of other ports, as follows: 80 Dec 07, 2005 · To allow Internet Key Exchange (IKE), open UDP 500. To allow IPSec Network Address Translation (NAT-T) open UDP 4500. To allow L2TP traffic, open UDP 1701. Here’s the Cisco access list: (gre=Protocol ID 47, pptp=1723, isakmp=500) access-list OUTSIDE permit gre any host OUTSIDEIP access-list OUTSIDE permit tcp any host OUTSIDEIP eq pptp UDP 1701. Point-to-Point Tunneling Protocol (PPTP) TCP/UDP 1723. Remote Desktop Protocol (RDP) TCP/UDP 3389. Terminal Access Controller Access-Control System (TACACS

The UI NG uses is a global router model template. Most of the UI features are embeded in the UI and then depending upon model of product, various features are hidden depending upon model product feature support.

Guaranteed communication over port 1701 is the key difference between TCP and UDP. UDP port 1701 would not have guaranteed communication in the same way as TCP. Because protocol TCP port 1701 was flagged as a virus (colored red) does not mean that a virus is using port 1701, but that a Trojan or Virus has used this port in the past to communicate. I recently set up a VPN back into my network (for use on public wi-fi, keep they prying eyes away). Everything was working and now it is not. I checked the access to the port via the internet and they are now closed. Is VZ blocking UDP 500, 1701 and 4500 now.

Protocol: UDP, port 500 (for IKE, to manage encryption keys) Protocol: UDP, port 4500 (for IPSEC NAT-Traversal mode) Protocol: ESP, value 50 (for IPSEC) Protocol: AH, value 51 (for IPSEC) Also, Port 1701 is used by the L2TP Server, but connections should not be allowed inbound to it from outside.

2. L2TP port (UDP 1701) is not blocked by your firewall. iv. If interested in IKEv2 based VPN tunnel, make sure. IKE port (UDP port 500, UDP port 4500) is not blocked. v. If interested in SSTP based VPN Tunnel, make sure. SSTP protocol port ( tcp 443 ) is not blocked. Apr 15, 2019 · (IP Protocol TYPE 50) or is UDP 500 and 4500 enough? (some even say UDP 1701 could be necessary for IKEv2) Reply. Richard M. Hicks / August 13, 2019. Feb 28, 2014 · Port Configuration: Utilizes UDP 500, Protocol 50, UDP 1701 and UDP 4500. L2TP/IPSec provides a highly secure and reliable connection. L2TP is an advanced protocol when compared to PPTP and is combined with IPSec in order to obtain better security. The speed may be lower than PPTP but Internet speed varies based on a number of factors. ip nat inside source static udp 1701 1701 extendable ip nat inside source static tcp 1723 1723 extendable ip nat inside source static udp 4500 4500 extendable For L2TP you need ports 500 (UDP), 1701 (UDP), and 4500 (UDP). Forward these ports to the same ports internally. For PPTP, it would be ports 500, 1723 (TCP), and 4500, also forward the same internally. I don't know where it said to forward any UDP port to 1701, so I'm pretty sure that's your issue. UDP often uses ports 500, 1194, or 4500. One way that they detect VPNs is through the UDP connection to one of these known ports. Additionally, some ISPs monitor traffic for UDP connections. If your ISP detects UDP, they may cap your bandwidth. TCP typically uses ports 1701, 1723, and 443. My setup (which previously worked fine with the EE router), was to set up port forwarding rules for UDP 1701, 500 and 4500 to forward to the same ports on my Synology NAS, for use with it's L2TP/IPSec VPN server, and use DDNS to allow the router's IP to be found from anywhere.