The recent OpenVPN service abnormal quit many times, because the original in order to troubleshoot problems record a large number of debug log, resulting in problems when you want to locate the problem is very difficult, the instant log was brushed off, the process dropped, instantaneous start, instantaneous and dropped, resulting in a lot of orders lost! Because the day file records too much useless information, dare not to search the log to locate t
The recent OpenVPN service abnormal quit many times, because the original in order to troubleshoot problems record a large number of debug log, resulting in problems when you want to locate the problem is very difficult, the instant log was brushed off, the process dropped, instantaneous start, instantaneous and dropped, resulting in a lot of orders lost! Because the day file records too much useless information, dare not to search the log to locate t
The difference between an OpenVPN internal route and a system route is that the system route completely follows the longest prefix matching principle. After finding the route, the data packet is forwarded from the corresponding Nic interface. Although the routes inside OpenVPN ultimately decide whether to forward and where to forward data packets, this "whether to forward" and "where to forward" is very dif
OpenVPN client configuration tutorial in Ubuntu generally, Linux servers that provide Web Services seldom need to connect to OpenVPN, but personal Linux computers often need to connect to OpenVPN. For example, if you use Linux as the development environment, you need to connect to the company's OpenVPN. This document u
OpenVPN is the first choice for VPN servers. There are two solutions for how openVPN breaks through the firewall blocking. One is to use the http-proxy that comes with openVPN, second, use HttpTunnel
1. the http-proxy provided by liopenvpn breaks through the firewall blockingOpenVPN itself can use an http proxy. That is to say, the
1.
Environment 1.1. server environment
Centos6, kernel version: 2.6.32-71. el6The IP address is 192.168.122.180, and the tunnel IP address is 10.8.0.1.
Kernel must support Tun devices and must load iptablesCheck whether Tun is installed:
# Modinfo Tun
Filename:/lib/modules/2.6.32-71. el6.i686/kernel/Drivers/NET/TUN. KoAlias: Char-Major-10-200License: GPLAuthor: (c) 1999-2004 Max kranyansky maxk@qualcomm.comDescription: Universal tun/TAP Device DriverSrcversion: 7d2aaef89c71c83bbffa0deDe
Use openvpn + linux to quickly establish an enterprise VPN
Openvpn introduction http://openvpn.sourceforge.net/, not much said.
Openvpn can work in two modes:
One is the IP Route mode, which is mainly used for point-to-point
One is the Ethernet-based Tunnel Bridge mode, which is applicable to point-to-point and multi-point networks with multiple branches
The conf
Details of the Linux neighbor subsystem: confirm-OpenVPN server mode MAC address learning, confirm-openvpnmacIn the article parsing the aging time principle of ARP cache implemented by Linux, I analyzed the conversion of the neighbor subsystem of IPv4 on the Linux protocol stack and again pasted the state machine Conversion Diagram, but this figure is more detailed, because it has an external input, that is, confirm:
Note that if the socket or routi
By simply using the openvpn proxy, all traffic on the local machine will go through the Remote VPN Server. However, when we roll over the wall, it is generally the traffic webpage, that is, as long as the http traffic goes through the VPN. Openvpn combined with squid's http forward proxy can provide the wall-over function for Web browsing, while other traffic such as QQ and thunder still follows the normal
Configure openvpn in Ubuntu
First, make sure that the apt-Get of ubuntu can find the openvpn package.Sudo apt-Get update
Install openvpn packageSudo apt-Get install openvpn
Create an openvpn configuration file. The example can be found in the following path:/Usr/share/doc/
OpenVPN Increase the script for logging user log
Cat connect.sh
#!/bin/bash
time= ' Date +%f '
if [-f/etc/openvpn/log/openvpn_$time.log];then touch
/ Etc/openvpn/log/openvpn_$time.log
echo "' Date ' +%f%h:%m:%s ' User $common _name trust_ip $trusted _ip is login, REMOTE_IP is $ifconfig _pool_remote_ip, Mask is $route _netmask_1 ">>/etc/
Openvpn is actually used for transmission at the application layer. You can select UDP/TCP as the transmission protocol. UDP is more commonly used. The reason is described in this article.
Why openvpn network?
If I want to access the network resources of the Organization at home, VPN is a good choice, but in general, setting up a VPN requires a VPN Server, that is, at least one real IP address, this is not
VPN protocols: PPTP, L2TP, and OpenVPN1. Concepts of PPTP, L2TP, and OpenVPN Tunneling Protocols 1. Default port number of PPTP (Point to Point Tunneling Protocol): 1723 PPTP, or PPTF Protocol. This protocol is a new enhanced security protocol developed on the basis of the PPP protocol. It supports multi-protocol Virtual Private Network (VPN) and can pass the password authentication protocol (PAP) and Extended Authentication Protocol (EAP) to enhance
First, the working principle of OpenVPN
VPN technology establishes a private tunnel on the public network through key exchange, encapsulation, authentication and encryption, which guarantees the integrity, privacy and effectiveness of the transmitted data. OpenVPN is a new open source project emerging in recent years, which realizes a sslvpn solution.
Traditional SSL VPN through the port proxy method, the
After completing the OpenVpn Bridge Mode experiment under UbuntuServer10.04, this experiment on the routing mode involves two modes: the bridging mode and the routing mode, let's take a look at the differences between the two modes. The above content is available on the Internet. I just organized them into tables to make it easier to compare and understand. Experiment environment: (1) topology: (2) The two routers are simulated using the Dynamips simu
First, what is OpenVPN Static Key
According to the official document, the Static Key approach is a point-to-point (point-to-point) VPN.
Second, the advantages of OpenVPN Static Key
1. Easy installation2, easy to use, Windows, OS X, Linux can be used by the official client3, adopt the UDP way, the connection is more stable
Third, the OpenVPN Static Key's disad
Article title: use Openbsd and Openvpn to quickly establish an enterprise VPN. Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
Use openbsd + openvpn to quickly establish an enterprise vpn
Openvpn can work in two modes:
One is
OpenVPN Optimization-Establishment of TLS handshake Control CHannelAn optimization of the OpenVPN data tunnel is in progress. After referring to the concept and idea of the "giant frame", I carefully considered the design and implementation of the TCP/IP protocol stack, so I come up with a possible error, but at least it is very practical in my scenario: although the upper-layer protocol sends data, it does
Company demand: Need to build a OpenVPN in the Japanese server, and then through the proxy way to visit foreign sites.
Server IP:
[root@li493-137 ~]# Ifconfig
Eth0 Link encap:ethernet hwaddr f2:3c:91:ae:0a:55
inet addr:57.17.20.30 bcast:57.17.20.255 mask:255.255.255.0
Inet6 ADDR:2400:8900::F03C:91FF:FEAE:A55/64 Scope:global
Inet6 ADDR:FE80::F03C:91FF:FEAE:A55/64 Scope:link
Up broadcast RUNNING multicast mtu:1500 metric:1
RX packets:4620022758
OpenVPN DoS Vulnerabilities (CVE-2014-8104)
Release date: 2014-12-01Updated on: 2014-6 6
Affected Systems:OpenVPN OpenVPN Access Server Description:Bugtraq id: 71402CVE (CAN) ID: CVE-2014-8104
OpenVPN is an open-source ssl vpn toolkit.
In versions earlier than OpenVPN 2.3.6 and earlier than
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