The tag has no usage guidance.

learn more… | top users | synonyms (1)

0
votes
0answers
27 views

Can Linux decapsulate double GRE encapsulation?

For an application when the packets arrive at the receiving host, those packets are double GRE encapsulated (IP Hdr + GRE Hdr + IP Hdr + GRE Hdr + payload packet). I am wondering if Linux kernel in ...
1
vote
1answer
43 views

TCP over TUN: SYN/ACK is received, but no ACK is generated, and socket remains in SYN_SENT state

I am tunneling an outgoing TCP connection over a TUN interface set up by a program I wrote. The TUN interface basically just relays the packets to/from a proxy server, with minimal modifications (...
0
votes
2answers
145 views

iptables forward traffic to vpn tunnel if open

I've used the following guide to set up my raspberry pi as an access point: Raspberry Pi 3 as wifi access point I'm forwarding wlan0 to eth0 and NATing all my traffic. Works great! sudo iptables -t ...
0
votes
0answers
36 views

wget probelm with a tunnel connection using ssh

I know this is not a new question, but I have researched a bit and so far none of the answers I've seen gave me the answer. I have this situation: I´m working on a campus where the network is highly ...
0
votes
0answers
150 views

tun2socks (badvpn) - having trouble with setup

I am attempting to use tun2socks/badvpn to force all traffic through the tun device, but am having some issues. From wireshark, it appears that traffic is indeed going out properly, but not coming ...
0
votes
1answer
66 views

Reroute mysql connection through external machine

I want (as a first step towards an external mysql proxy) reroute traffic from the local connection of mysql (on a VM) to an external proxy (on the host) which then routes it back to the VM which will ...
2
votes
0answers
55 views

Why could policy routing on iptables marks applied in FORWARD or OUTPUT chains be inconsistent?

I am routing HTTPS connections down a SSH tunnel (-w) using iptables marks and iproute2 rules, the reasons I need to do it this way are contrived, to say the least, so most alternate solutions may not ...
0
votes
0answers
68 views

How to tunnel proxies on openwrt

Currently I have setup wifi access point on openwrt. I wonder how do I tunnel proxies and route all traffic through the tunnel. client=>proxy1=>proxy2=>google server I want to create kind of proxy ...
1
vote
0answers
24 views

Can I change owner of a tunnel after creating it?

I've been trying to finagle pytun to do my bidding in creating persistent ssh tunnels, but I very much do not want these to be owned by root and unless I modify the python package myself (which as a ...
1
vote
1answer
46 views

Confirming that a reverse ssh tunnel has been established

I have a reverse ssh tunnel established between a client and a server computer. The client connects on the server on port 22, and creates a reverse ssh tunnel on port 4030. After the client computer ...
-1
votes
4answers
179 views

Ssh into a remote server, but my organization has blocked port 22

I am using Redhat Openshift server to deploy my webapps. To access the contents of my application I have to ssh into their server. Example ssh 56555ff90abcdefbf6e000077@appname.rhcloud.com ...
0
votes
0answers
28 views

How to get informed about EVERY incoming ssh connection (e.g. with no remote command specified)

The case I'm used to set up automatic reverse ssh tunnels to remote computers via my server with cron. Usually I use the following entry: @reboot sleep 300 && ssh -MNf -R xxx22:host:22 user@...
2
votes
1answer
157 views

Why doesn't FTP work through my ssh tunnel?

Computer A (assumed that ip is 44.44.44.44)can ftp the host 130.89.148.12. ftp 130.89.148.12 Connected to 130.89.148.12. 220 ftp.debian.org FTP server Name (130.89.148.12:debian8): anonymous 331 ...
0
votes
2answers
81 views

set up secure connection over SSH

I'm setting up a server application which requires to establish a secure connection over SSH2, e.g. a client must open SSH2 connection to the server to reach specific application: % ssh -s -p5000 my....
0
votes
0answers
21 views

ip-tunnel: “Tunneling with a fixed ttl always makes pmtu discovery” - why?

The manual page for ip-tunnel says: ...fixed ttl is incompatible with [no PMTU discovery] option: tunneling with a fixed ttl always makes pmtu discovery. What is the reason for this? I do not see ...
1
vote
0answers
32 views

Having troubles connecting through tunnel to a server [closed]

Since yesterday I'm failing connection to my server partition on my school server. To access to my server I need to pass through a tunnel that require a password and connect me to the server. This ...
0
votes
1answer
80 views

Is port forwarding always used in proxy server, gateway and tunneling?

It seems to me that proxy server, gateway and tunneling all forward traffic that they receive to the actual destinations. So is port forwarding always used in proxy server, gateway and tunneling, or ...
2
votes
1answer
1k views

ssh into a server which is connected to a VPN service

I have a virtual private server, which I would like to run a web server while my server is connected to a VPN service When the VPN connection to my provider is not up, I can do anything I want with ...
3
votes
1answer
94 views

“ssh -L <port>” only working from local machine

I mean if I've got something like this: ssh -L 9000:itc.ua:80 andy@localhost It will open port 9000 on my local machine and when I hit http://localhost:9000 in Firefox it will forward to itc.ua:80 ...
2
votes
1answer
278 views

Tunnel all network traffic through another Linux server

I have two VMs both running Ubuntu 14.04, one is connected to the internet and accessible publicly but the second one is not. Now whenever I want to install something or run apt-get update, it does ...
2
votes
2answers
101 views

Using reverse SSH tunneling in one step instead of two steps (with -X)

Suppose we have three hosts: miki - my computer behind a NAT vps0 - my VPS mum - computer of my mother, behind a different NAT. The task is to connect from my computer to my mum and keep X11 ...
1
vote
1answer
148 views

SSH Tunneling - Local and Remote Use Cases

I just learned the basics of SSH tunneling from googling. I saw this interesting question: How does reverse SSH tunneling work? But I still find it a bit confusing, more specifically on the user@...
2
votes
0answers
117 views

More than 255 Linux GRE tunnels

Is it possible to set up more than 255 GRE tunnels in Linux? It seems that 255 is the default maximum, but is there any way to increase the limit?
1
vote
0answers
37 views

Why is a Linux Tun interface not returning ICMPv6 Echo replies?

I wrote a program which connects to a TUN interface and replies to ICMPv6 Echo Requests. Even though I can successfully observe the echoes and replies with tcpdump on the TUN interface, it appears ...
3
votes
0answers
25 views

How to unwrap a tunneled packet in iptables/netfilter and process the tunneled packet

I have a specific question regarding the Linux netfilter/iptables interaction. Let's say I have an IP packet P1 inside of another IP packet P2 (that is, P1 is tunneled). Now, the question is as ...
1
vote
0answers
55 views

Tunslip deactivates WiFi in raspberry pi B+ board

I'm using Contiki operating system with Cooja to simulate a sensor node network. And I'm trying to capture the ip packets it's sending in a Raspberry Pi B+ board (through USB) using tunslip6 and a ...
4
votes
0answers
348 views

Restart a specific reverse ssh tunnel?

I have multiple machines in the wild that open reverse ssh connections to my server. Each machine out there is using a different reverse ssh port, which I use to differentiate between the machines. I ...
3
votes
1answer
2k views

Please help me to understand these tun0 addresses

I have already done some searching and more or less understand what a tun0 interface does. I got the following from various sources, Packets sent by an operating system via a tun/tap device are ...
1
vote
0answers
140 views

It is possible to make an IPSEC VPN Bonding?

I wanted to know if It is possible to bound two IPSEC tunnels ? I've already done a VPN bonding of SSH tunnels, but It will be better if I use IPSEC.
0
votes
1answer
276 views

How do I tunnel traffic through a VPN and then through another machine

I recently started working from home using a laptop (A) that connects to a corporate network over a VPN. The VPN end point (B) on the corporate side then has two ports, 3389 for RDP and 22 for ssh, ...
1
vote
0answers
186 views

SFTP connect through an other server

I want to connect to my account in a server of my university. When I’m there I only have to do ssh user@FinalServer/home/user or create a folder using sftp://user@FinalServer/home/user But the ...
2
votes
1answer
795 views

Loading kernel modules that were compiled for another kernel failed

I want to load kernel modules, ip_gre.ko and gre.ko, on a embedded-device running embedded-linux to make that device to support GRE protocol. Since I do not want to change Embedded-linux device's ...
0
votes
1answer
142 views

Redirect traffic through the server

My task is to redirect traffic (port range) through the server. Here is the schema: Why NAT is not appropriate here: If NAT is set to "Tunnel Server", then all users will be assigned the same IP. ...
0
votes
1answer
229 views

GRE not Forwarding origin IP

I've followed the BuyVM Guide found here on creating a GRE Tunnel to protect my main server against DDOS attacks (http://wiki.buyvm.net/doku.php/gre_tunnel) I've followed through this whole guide ...
1
vote
1answer
44 views

Access network of PC2 from virtualbox installed on PC1

I am going to attend one seminar where I need to bring laptop with installed Virtualbox and Windows 7 running inside it. My laptop is too old to handle Virtualbox with Windows 7 and native Linux ...
2
votes
0answers
101 views

debugging iptables when tunneling one VPN through another

I seek to tunnel one SSL VPN (F5, running on my debian laptop==client) through another (OpenVPN, running on a debian linode==server), but lose all client networking (including, e.g., ping) after the ...
1
vote
0answers
89 views

Transparent proxy to other IP of thousand ports

I was bought a service that only allow a IP, the IP that i say, only one, but I need use this from more IP's. I think that I can install in this computer a system to do a transparent proxy for ...
1
vote
1answer
343 views

Resolving DNS through HTTP/HTTPS

Is there a way to resolve DNS through HTTP/HTTPS, the case was: my ISP redirecting every DNS request to their own DNS and poisoning the DNS records. all I need is a software that could resolve ...
2
votes
0answers
695 views

how to open up socks/SSH on different network interfaces?

iptables -A PREROUTING -i usb0 -t mangle -p tcp --dport 8080 -j MARK --set-mark 1 iptables -L Chain INPUT (policy ACCEPT) target prot opt source destination Chain ...
1
vote
1answer
130 views

Why does my tunneled IPv6 connectivity drop after a short period of time?

I correctly setup a Hurricane Electric tunnel on a CentOS 6.5 VPS server (KVM). I use CSF (ConfigServer Security & Firewall) which acts as a wrapper for iptables and ip6tables, the default ...
1
vote
0answers
206 views

Establish IPSEC Tunnel between two Ubuntu 12.04 PCs over LAN

I have two ubuntu 12.04 32 Bit PCs between which I want IPSec Tunnel to be setup. I have setup ipsec in both systems and ipsec verify runs fine on both. Since I have no prior experience of openswan, I ...
2
votes
1answer
2k views

Forwarding packets from loopback interface with policy-based routing

I have the following iptables rule: iptables -t mangle -A PREROUTING -p udp -m udp --dport 10000 -j MARK --set-xmark 0x4/0xffffffff which sets fwmark 4 on all udp packets with destination port ...
1
vote
1answer
1k views

VNC & SSH : local (win-putty) -> hop (linux) -> remote (linux)

I'm gettin a headache trying to access a remote VLC & SSH. This is the situation : Local : Win box behind NAT, dynamic IP. I want to connect from here. Hop : Linux box, static IP server Remote :...
1
vote
0answers
134 views

How to get information from sshd about established remote tunnels

I have a server running on which from many different places people log on via ssh and open remote ssh-tunnels to other places behind different firewalls. Now I want to try to get an overview, which ...
1
vote
1answer
1k views

Bridged TAP interface to virtualbox

I need bridged TAP interface on client side of my VPN to virtual machine. I use VirtualBox 4.3.12. But in Adapter Network options in Attached to: Bridged adapter I do not see my TUN adapter. I have ...
1
vote
0answers
413 views

Packets sent through TUN interface not routed

I have a C program attached to a TUN interface. In my C program, I'm building packets and writing them to the TUN interface. Now to check if packets are really sent from my TUN interface I use ...
1
vote
0answers
181 views

Local Client/Server communication using TUN interfaces

I want to establish a local communication between a client and a server using TUN interfaces. The client program will be attached to interface TUN1 and we suppose that it has IP address @IP1. The ...
1
vote
0answers
794 views

IPsec Tunnel mode - RoadWarriors configuration

I've the need to configure IPsec tunnel mode between a gateway with static NAT (let's say its public IP is 172.31.0.105) and a number of clients that are behind dynamic NAT. Reading through some ...
3
votes
1answer
106 views

What is the best way to create remote tunnel?

I have 3 Linux servers: 10.0.0.0/24 - (10.0.0.10) Linux server inside my LAN. 20.0.0.0/24 - (20.0.0.10) Linux server with HTTP Apache server 50.50.50.50/32 - Server on Amazon AWS which see ...
2
votes
1answer
135 views

Kernel optimiziations for ioctl AF_INET operations

Our server solution handles many tunnel operation requests (add/update/delete) using the ioctl interface, and the AF_INET address family socket. Aprox. numbers are 100 operations/minute with over 8k ...