Questions tagged [gre]
Generic Routing Encapsulation (GRE) is a tunneling protocol, developed by Cisco.
124
questions
1
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0answers
32 views
Centos GRE Tunnel
I have two servers. Centos 7 installed on both.
Main Server: 45.x.x.yy/32
Slave Server: 185.x.x.yy/32
I want to use the ip address of the Slave Server on the master server by establishing a GRE Tunnel ...
0
votes
0answers
23 views
Pfsense GRE to Proxmox Openvirtualswitch gateway not going up
So, I run pfsense on Hetzner Cloud and proxmox on Hetzner Cloud. Both are VMs. The Hetzner network is very restricted. I found a solution: GRE tunnels.
The following setup works:
pve machine = 10.0.0....
0
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1answer
41 views
Routing one machine's traffic through GRE tunnel to a remote NAT
I had to solve the following dilemma for a friend and thought I'd document how we did it here...
Here's the situation:
His home network 192.168.1.0/24 and it sits behind a Linux router that performs ...
0
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0answers
44 views
GRE Tunnel subnet /29
I watched this tutorial: https://www.lowendtalk.com/discussion/156850/howto-tunnel-ddos-protected-ovh-ip-to-vms-in-other-datacenter
And I have problems with the GRE tunnel, I created a VPS on server 2 ...
0
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0answers
31 views
How to route traffic from nat interface through GRE Tunnel? - Debian
I have these two dedicated servers, let's call them A and B;
I've created a GRE tunnel between the two and it works as supposed to.
On server A, I also have a NAT interface configured and it works but ...
-2
votes
1answer
115 views
GRE tunneling using Open vSwitch
I am trying to implement tunneling as described here with the following setup (without any success):
ho1 is a host only interface. I want to connect Nested Guest 11 and Nested Guest 21.
I have read ...
0
votes
1answer
49 views
Use working GRE tunnel as default on remote server
Purpose is to "protect" my backend dedicated server (B) using a front VPS (A) with a GRE tunnel and use the the new stablished interface (GRE1) as default on (B) in order not to leak the ...
0
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0answers
43 views
PPTP & GRE issue iptables/NAT
This is my first post and will try my best to add all the info.
I am trying to accomplish something that i am not sure if it is supported, basically
I have a firewall that is configure to allow ...
0
votes
2answers
91 views
How can I set up a point-to-point IPv6 GRE tunnel encrypted with ipsec between my Mikrotik CCR2004 router and a Linux host running Strongswan?
I need to encapsulate IPv4 in IPv6 for routing purposes. One end is a Linux box running quagga, and the other end is a Mikrotik CCR2004. How?
0
votes
1answer
20 views
EdgeRouter Route Incoming Traffic to another Public Network/Server
I am curious if this is possible in theory? At my colo datacenter, I have a lot of public IP addresses (/21) on a 1GB circuit using an Edge Router 6P (not using BGP). I want to temporarily rent a ...
0
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0answers
103 views
Tunnel keep-alive issue between Cisco and Mik router
I really need your help.
I'm trying to connect a Mikrotik router with a Cisco router with GRE tunnel using Public IPS.
The problem is when I try to configure keep alive between both routers the tunnel ...
2
votes
0answers
73 views
Unable to setup a GRE tunnel between 2 servers
I currently have 2 servers:
Server A: 2.2.2.2
Server B: 3.3.3.3
I want to create a GRE tunnel from server A to server B.
I have ipforwarding enabled on server A:
cat /proc/sys/net/ipv4/ip_forward
1
...
0
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0answers
62 views
A gre tunnel between Mikrotik and Cisco router
I really need your help
I'm trying to connect a Mikrotik router with a Cisco router with GRE tunnel using Public IPS
the problem is when I try to configure keep alive between both routers the tunnel ...
3
votes
1answer
155 views
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 ...
0
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0answers
148 views
Docker container with GRE network incorrect checksum
I have a server with docker, whose containers connect to the internet via a GRE tunnel. My configuration looks like this (bridge network):
{
"Subnet": "10.0.0.128/25",
&...
0
votes
0answers
213 views
Docker network bridge GRE tunnel
I am currently trying to setup a network docker bridge with a GRE tunnel.
I have setup the GRE tunnel fine and the GRE tunnel is working, however, whenever I tried to use docker with it, it wouldn't ...
0
votes
0answers
97 views
Cannot Locate IPIP Tunnel With Specific Remote IP
I have a dedicated machine running on Ubuntu 20.04 with kernel 5.4.0-52-generic. I use something called Docker Gen (running this configuration) to setup IPIP tunnels when a Docker container starts and ...
0
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0answers
49 views
GRE Tunnel - Trasfer /30 subnet to remote KVM host
Tutorial used: click here
Commands used both servers:
Server 1
ip tunnel add gre1 mode gre remote 9.176.110.209 local 212.188.100.58 ttl 255
ip link set gre1 up
ip route add 212.188.103.64/30 dev gre1
...
0
votes
0answers
612 views
Setting up a GRE tunnel on Windows Server 2019
I am trying to etablish an GRE tunnel to my Windows Server 2019, which seems easy enough.
Although things get a bit complicated, as I want my applications to bind to the IP on the other side of the ...
0
votes
1answer
191 views
preventing ipv6 packets from being generated when creating a gre tunnel
I have a veth device, each side of it is in a different network namespace on the same machine. I am creating a gretap tunnel over this veth. when setting the gretap device to up state I can see a lot ...
0
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0answers
117 views
Suppressing ICMP protocol 47 unreachable with userspace GRE implementation
For reasons that would require a lot of irrelevant context to explain, I'm handling GRE packets with a userspace process with a SOCK_RAW/IPPROTO_GRE socket. This is working fine, except that despite ...
0
votes
1answer
167 views
Tunnel Linux traffic to Windows
I have two servers. Windows and Linux. Let's say Linux has the IP 1.2.3.4 and Windows 5.6.7.8. I want all traffic to be forwarded to windows as a tunnel. If I connect with 1.2.3.4:329 I want to ...
0
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0answers
380 views
Forwarding Home Game-Server through GRE Tunnel | Can't ping remote GRE IPs
I am having trouble routing my game-servers through GRE. I do not receive a ping from either side when pinging them. I can ping the local GRE interface; however, I cannot ping the remote GRE interface....
0
votes
1answer
298 views
Packets not getting forwarded on Centos7 between GRE tunnels
I'm have configured GRE tunnels between centos machines and corresponding routing tables on individual centos machines as shown in the image:
I dont have enough reputation to post images
Router1-----...
0
votes
1answer
271 views
Interface bonding on GRE tunnel with nmcli
I have two Ubuntu server-based routers and I'd like to bond (in broadcast mode, since I only care about redundancy) a radio link (where the radio equipment is connected to an Ethernet port) and a LTE ...
0
votes
1answer
174 views
gretap tunnel return traffic not being handled
I'm using iproute2 to add a GRE layer 2 tunnel with a vlan tag as shown below.
ip link add name gre1 type gretap local 10.0.0.2 remote 8.8.8.8
ip link add name gre1.100 link gre1 type vlan proto 802....
3
votes
0answers
424 views
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 ...
0
votes
0answers
79 views
ACK packet lost in GRE tunnel for IPv6 in IPv4
At home (79.1.1.156), my ISP doesn’t provide IPv6 so I’m connecting my server to an external server (95.1.1.126) that has IPv6 access via a GRE tunnel, with this simple setup:
ip tunnel add gretun ...
0
votes
1answer
42 views
Seperate GRE tunnels cannot ping eachother
I have two systems that both tunnel to a core routing server. These systems both have a client address from the same /64 IPv6 prefix. From each client, I can ping the server with no problems and vice ...
0
votes
1answer
353 views
GRE Tunnel Dies in 1 direction
I have built a GRE tunnel over tap0 interface between 2 Centos-7 hosts. I've done this via the following:
Host-A: 10.0.10.5
Host-B: 10.0.20.5
On host A:
ip tunnel add tap0 mode gre remote 10.0.20....
0
votes
1answer
587 views
Route incoming traffic through GRE tunnel
So I have a VPS and Dedi server both running Debian 9.9.
139.99.x.x: VPS
139.89.x.x: DEDI
The Dedi server runs a game server but can't be directly accessible, I want to route all traffic through my ...
0
votes
3answers
546 views
GRE traffic not forwarded to local subnet
I have two debian machines in difference locations and want to enable routing between the two internal subnets via GRE.
My general routing is already working, meaning any internal machine directs ...
0
votes
0answers
2k views
Using iptables NAT to forward GRE tunnel
I have two hosts which need to have a GRE tunnel between them. In between the two I have a relay host which needs to perform NAT and forward the GRE traffic in either direction.
grehostA --- ...
3
votes
3answers
5k views
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 ...
0
votes
1answer
458 views
ERSPAN to IP on Centos host with multi interfaces on the same subnet
I have an interesting configuration and would like some help getting it to work.
On a hardware network monitoring probe, i have 2 physical interfaces. mgmt is the management interface and mon1 is a ...
0
votes
1answer
489 views
Linux GRE Tunnel: Remote Address parameter
The Linux GRE tunnel as two parameters, local address and remote address. Suppose I have two routers, the left one is outside of a NAT and right one is inside NAT, then I want to create a GRE tunnel ...
0
votes
1answer
236 views
GRE perfomance issue on Linux
I got a strange GRE perfomance issue.
The setup is shown bellow.
[host1] --- GRE over Eth 1G --- [linux router] --- Eth 10G --- [host2]
Iperf transfer rate host1>host2 reaches 950Mbps. It encreases ...
0
votes
1answer
372 views
tc qdisc with GRE in openwrt
I'm trying to implement traffic control to GRE interface in an openwrt board.
For this i followed below steps,
Create GRE interface named gre1 in both tunnel end devices.
Tested reachability with ...
2
votes
1answer
1k views
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 ...
0
votes
2answers
3k views
Packet loss in IpSec/GRE tunnel
This is my setup:
+--------------------+ +-------------------+ +--------------------+
| Router B a +-----+ Router+Firewall C | | b Router D |
| 10.10.10.1 -----------...
0
votes
1answer
2k views
GRE Tunneling not working
i've been looking everywhere for a solution to this but have found really nothing. I was wondering if it is possible to forward ports such as 80 through an OpenVPN connection? I am using an OVH VPS ...
2
votes
1answer
1k views
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 ...
2
votes
1answer
1k views
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 ...
1
vote
1answer
2k views
iptables SNAT not working for GRE packets
I am trying to apply SNAT to a PPTP client. The TCP/1723 packets are being SNATed properly but not the GRE ones. Can anyone spot what's wrong?
I have the following iptables configuration:
$ sudo ...
1
vote
1answer
278 views
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....
0
votes
1answer
546 views
Nat over GRE using IPsec VPN tunnel
I’m working on implementing VPN tunnel IPSec GRE from Natted Linux box with Ubuntu.
I have found a very useful article, related to IPSec-GRE tunnel behind NAT, made with Cisco routers. I have ...
1
vote
1answer
811 views
L2TPv3 tunnel private IPs not working
I'm trying to setup L2TPv3 tunnel between 2 servers - CentOS 7 and Ubuntu 16
On CentOS 7 end I have the following:
ip l2tp add tunnel tunnel_id 6000 peer_tunnel_id 5000 encap udp local LOCAL_IP ...
0
votes
1answer
3k views
IPSEC over GRE tunnel on PFSENSE
I have two PFsense routers xxx.xxx.xxx.28 and xxx.xxx.xxx.27 and local networks behind them 192.168.110.0/24 and 192.168.111.0/24. The point is to set up GRE tunnel with IPSEC between these networks. ...
0
votes
1answer
361 views
GRE With scaleway
i'm having some problem here to create a GRE tunneling,
it' theoretically simple, i have 2 clouds, one, with DDoS Protection,
and another, without that.
In my first cloud, it have DDoS, hosted in OVH, ...
1
vote
2answers
5k views
PPTP Passthrough Centos 7/Firewalld router to Windows Server
I have a Centos 7 server running firewalld to allow public services to access internal services on a separate VLAN (dual NICs). I imported a Windows VM but I do not know what rules I need to put in ...
