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Questions tagged [gre]

Generic Routing Encapsulation (GRE) is a tunneling protocol, developed by Cisco.

Generic Routing Encapsulation (GRE) is a tunneling protocol, developed by Cisco.

131 questions
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3 answers

Cannot Delete GRE Tunnel

I am configuring a GRE tunnel in Linux 2.6.26 and I've been facing a very strange problem for which I could not find any solution. I have created a GRE tunnel called gre0, but no matter what I do, I am simply unable to delete this tunnel. The…
alecov
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1 answer

GRE tunnel TTL number

Here is the setting on server A: iface serverA_gre0 inet tunnel address 172.24.0.85 mode gre endpoint x.x.x.x dstaddr 172.24.0.86 netmask 255.255.255.252 ttl 255 Setting on server B: iface…
Thomas G. Lau
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1 answer

PPTP connection fails with errors 800/806

I've got a client (Server 2008 R2) that won't connect to our production environment PPTP VPN server (Server 2003, running RRAS). The server is behind a firewall that has TCP1723 open as well as GRE. Other clients at our office are able to connect…
Mark S. Rasmussen
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4
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1 answer

Multiple GRE tunnels on the same host, only one routes incoming packets

I'm having a routing problem on CentOS 6.2 (kernel 2.6.32-220) Here's the setup: One host is on my local network. It's talking to two nearly identical hosts at a remote location. The two remote hosts are on all the same networks, acting as…
Rick Koshi
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0 answers

How to route server_A's internet traffic through server_B using a GRE Tunnel?

I have two Linux servers. I want to use a GRE tunnel to route all internet traffic from ClientBox through a tunnel to GatewayBox, so that, to the rest of the internet, my ClientBox appears to be GatewayBox, and so that I can use GatewayBox's…
socksilly
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3
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3 answers

Allow GRE (IP protocol 47) over Linux router NAT for a subnet

I have network setup as shown below: The VPN server running is windows 2012 server default VPN, which uses GRE protocol. I am able to have VPN connection to that remote vpn server, from my intranet single IP only. But I am not able to connect for…
Shyamkkhadka
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1 answer

How to setup a GRE 3 host mesh without loops and forwards with OpenVSwitch?

I'm setting up a quite simple 3 host Proxmox (Debian) HA cluster. All VMs should be in the same subnet and when one fails over to another host inside the VM no reconfiguration should be required and connectivity to all VMs on the remaining hosts…
Jey DWork
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3
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1 answer

Poor IPsec over GRE performances

I have set up an IPsec over GRE connection with a remote host, both are NetBSD 6.1 based. The "client" is connected to the Internet through a 400Mbps fiber connection. The "server" is located on a 10Gbps network. Both machines have 1Gbps NICs which…
iMil
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3
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1 answer

Multicraft: Port Forwarding through a GRE Tunnel

For the past week I've been attempting to protect a server from DOS attacks by utilizing a GRE tunnel from a VPS to a dedicated machine without much success. Visual: User --> VPS --> Dedicated Server I've followed several guides BUYVM and Minecraft…
Brian McDonald
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1 answer

How GRE traffic finds way after arrive GRE remote end points (in open vswitch)?

I'm quite new to both network and open vswitch, I'm not sure whether this question is more relevant to open vswitch(ovs) or gre. belows are ovs settint commands. There are two hosts. Each host has two bridge br1 and br2. br2 has the gre tunnel…
jinhwan
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4 answers

How to setup an IPSec / GRE tunnel on Windows Server 2008

I have a Windows Server 2008 that has a single network interface configured with a public IP address. My business partner has a private network. From my server, I need to access all the devices on his private network, and those devices must be able…
qbeuek
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1 answer

Reading back Linux gre[tap] local/remote address

With iproute2 on Linux, gre/gretap interfaces are setup with ip link add, which for GRE needs remote and optionally local attributes specifying the endpoints. However, I can't find any way to read back these attributes. ip link show doesn't show…
R.. GitHub STOP HELPING ICE
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1 answer

Get IP over DHCP for GRE-tunnel

I need to create a GRE tunnel from a client to a server. This is my setup. Setup: ________________________________ _________________________________ ______________________________ |Server | | |Router | …
Kev Inski
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1 answer

Bonding over OpenVPN, for fault tolerance

I have two OpenVPN server, and two machines connecting to them. Server 1 openvpn address: 10.158.1.1 Server 2 openvpn address: 10.158.2.1 Machine 1 has address 10.158.1.11 on server 1, 10.158.2.11 on server2. Machine 2 has address 10.158.1.12 on…
WorK
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1 answer

Public to Public IP GRE

I've managed to setup a GRE tunnel between two servers using BuyVM's very great guide (also used a guide via ServerFault) It simply works. I can ping internally So. To get into perspective: A = 1.1.1.1 B = 2.2.2.2 DDOS PROTECTED IP: C =…
Kevin Als
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