gre tunnel basics

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  • MikroTik Site to Site GRE Tunnel Configuration with IPsec

    VPN (Virtual Private Network) is a technology that provides a secure tunnel across a public network. A private network user can send and receive data to any remote private network using VPN Tunnel as if his/her network device was directly connected to that private network. MikroTik provides GRE (Generic Routing Encapsulation) tunnel that is used to create a site to site VPN tunnel. GRE tunneling protocol which can encapsulate a wide variety of protocols creating a virtual point-to-point link was originally developed by Cisco. GRE is a stateless tunnel like EoIP and IPIP. That means if the remote end of the tunnel goes down, all traffic that was routed over the tunnels will get blackholed. To solve this problem, RouterOS have added ‘keepalive’ feature for GRE tunnels. By default keepalive is set to 10 seconds and 10 retries. GRE adds an outer header mentioning the entry point of the tunnel (SourceIP) and the exit point of the tunnel (DestinationIP) but the inner packet is kept unmodified. GRE tunnel only encapsulates IP packets but does not provide authentication and encryption. GRE tunnel with IPsec ensures IP packet encapsulation as well as authentication and encryption. IPsec usage makes your packets secure but [...]

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    MikroTik Bandwidth and Resource Monitoring with Graphs |   January 31, 2018

    “Am I getting my committed bandwidth?” is a common question to any network administrator. This question may arise either from your customer or from your owner if you are an employee of any organization. If you feel boring hearing this question and want to establish a system where your customer will be able to inspect his bandwidth usage, MikroTik Graphing is your best friend. MikroTik Graphing can be used to display graphics for traffic which is passed through interfaces and [...]

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    Hardening MikroTik RouterOS by Limiting Login Services |   February 6, 2021

    MikroTik RouterOS is usually used as a bridge between WAN and LAN network. WAN network is always an insecure network because attackers always try to hack your RouterOS so that they can compromise it for their own benefit. As a network administrator of MikroTik RouterOS, we should always take anti hacking steps to secure our MikroTik RouterOS. There are a lot of security tasks those we should take care to secure our MikroTik RouterOS. Among these security tasks, we will [...]

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    How to Mount USB Device in CentOS 7 (NTFS and Linux FS) |   February 18, 2019

    USB Hard Disk Drive or USB Flash Drive (Pen drive) is a popular external device that can be used to backup data or transfer data from one device to other device. In GUI (Graphical User Interface) Operating System such as Window or GNOME Desktop in Linux can automatically mount USB device and can show data in it if the File System of that device is supported. But all users do not like or always do not have GUI mode of [...]

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    MikroTik L2TP/IPsec VPN Configuration (Connecting Remote Client) |   February 26, 2018

    VPN (Virtual Private Network) is a technology that provides a secure and encrypted tunnel across a public network and using this VPN tunnel a private network user can send and receive data to any remote private network as if his/her network device was directly connected to that private network. MikroTik L2TP server is one of the most popular VPN services. It provides a secure and encrypted tunnel across public network for transporting IP traffic using PPP. L2TP/IPsec is more secure [...]

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    MikroTik Site to Site OpenVPN Server Setup (RouterOS Client) |   April 9, 2018

    VPN (Virtual Private Network) technology provides a secure and encrypted tunnel across a public network. So, a private network user can send and receive data to any remote private network through VPN tunnel as if his/her network device was directly connected to that private network. MikroTik OpenVPN Server provides a secure and encrypted tunnel across public network for transporting IP traffic using PPP. OpenVPN Server uses SSL Certificates. So, OpenVPN Tunnel is a trusted tunnel to send and receive data [...]

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    WireGuard VPN Setup in MikroTik RouterOS7 with Windows OS |   August 14, 2022

    VPN (Virtual Private Network) is one of the most popular services in MikroTik RouterOS. A lot of VPN services (IPsec, EoIP, OpenVPN, PPTP, L2TP, IPIP etc.) are available in MikroTik RouterOS but in RouterOS7, a new VPN service named WireGuard has been introduced which is extremely simple yet first, secure and modern VPN. WireGuard uses cryptography to make it secure. In RouterOS7, WireGuard can be used either Client-Server (Road Warrior) VPN tunnel or site to site VPN tunnel. Using Client-Server [...]

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    LVM Management in CentOS/Red Hat 7 Linux |   March 15, 2019

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