L2TP 隧道设置和终止 - Cisco

L2TP/IPsec¶ L2TP/IPsec is a common VPN type that wraps L2TP, an insecure tunneling protocol, inside a secure channel built using transport mode IPsec. L2TP/IPsec is supported starting with pfSense® software version 2.2-RELEASE. This article will explain how to configure the service and setup clients. set vpn l2tp remote-access client-ip-pool start 192.168.100.240 set vpn l2tp remote-access client-ip-pool stop 192.168.100.249 set vpn l2tp remote-access dns-servers server-1

set vpn l2tp remote-access dns-servers server-2
set vpn l2tp remote-access outside-address
set vpn l2tp remote-access mtu commit ; save Feb 25, 2016 · L2TP’s double encapsulation feature makes it rather secure, but it also means it’s more resource-intensive. L2TP normally uses TCP port 1701, but when it’s paired up with IPSec it also uses UDP ports 500 (for IKE – Internet Key Exchange), 4500 (for NAT), and 1701 (for L2TP traffic). The L2TP data packet structure is as follows: IP Header Jan 07, 2019 · /ip firewall filter add action=accept chain=input comment="L2TP VPN" dst-port=500,1701,4500 \ in-interface=ether1-wan protocol=udp src-port="" add action=accept chain=input in-interface=ether1-wan protocol=ipsec-esp add action=accept chain=input in-interface=ether1-wan protocol=ipsec-ah add action=accept chain=forward dst-address=172.19.190.0/24 src-address=\ 172.19.187.0/24 add action=accept The UDP ports 500, 1701, and 4500 should be open in port forwarding rules (at Network Center > Port Forwarding) and firewall rules (at Network Center > Security) of the Synology Router. And from Synology support: You need to make sure to port forward the required ports to the new L2TP/IPEC network, to allow external access:

L2TP是一种工业标准的Internet隧道协议，功能大致和PPTP协议类似，比如同样可以对网络数据流进行加密。不过也有不同之处，比如PPTP要求网络为IP网络，L2TP要求面向数据包的点对点连接；PPTP使用单一隧道，L2TP使用多隧道；L2TP提供包头压缩、隧道

RFC 3193 Securing L2TP using IPsec November 2001 If the responder chooses not to move to a new port number, the L2TP tunnel setup can now complete. 4.2.4. Responder chooses new Port Number The responder MAY choose a new UDP source port to use for L2TP tunnel traffic. This decision MUST be made before sending the SCCRP. I am trying to use it as my VPN, but when I set up port forwarding on the router I am not having any luck. It appears that I am forgetting something. I have tried ip nat inside source static udp 192.168.xxx.xxx 500 interface Fa0/0 500 for all three ports (500/1701/4500) needed for L2TP, but I cannot seem to connect. Any advice would be appreciated.

VPN端口号：PPTP、L2TP - XShell.NET - 业界技术 …

centos7 配置PPTP、L2TP、IPSec服务 - LeeQi92 - …