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Questions tagged [forwarding]

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How can the IP masquerading forwarding through a VPN gateway be configured to access the WAN router the gateway is attached to?

I have a gateway machine on my network running a VPN which routes outgoing traffic through a router, but the masquerading rules prevent the machines on the network from connecting directly to the ...
2
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1answer
44 views

In X11 SSH forwarding, keyboard isn't working properly (Only Ctrl + .. and numeric keypad works!)

I'm using Ubuntu 18.04 desktop at the office. In order to work with server, we're required to connect to a remote Windows 8 machine, and then open SSH connect to an Ubuntu 16.04 server from here. ...
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0answers
48 views

VOIP worked with Mint 19.1 & kernel 4.4, fails w/ kernel 4.8

With Linux Mint 19.1, kernel 4.15, I connect to the Internet using WiFi, and want to share the Ethernet connection with a Grandstream IP Phone. I have done: click | network connection | wired ...
0
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1answer
30 views

Can't access SNMP stack on rasp pi through router from WAN

Background I am running the following On my laptop the very latest version of arch linux with all the latest updates. It is from this laptop that I am querying an SNMP stack on a rasp pi $ uname -...
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0answers
48 views

Linux iptables forwarding

I've 3 machines : 1 server with LAN card without internet direct access 1 Windows host with WiFi connection for Internet and 1 LAN port 1 linux virtual machine on the Windows host [...
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2answers
41 views

How to check if a packet reached an interface in a multi-interface context?

Consider the following topology: I am sending ICMP (ping) packets from host B to 10.0.1.1. They reach the target and the target answers with a reply. The connectivity works fine. When running, on ...
0
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1answer
79 views

Masquerade rule with netfilter-persitent

I use netfilter-persistent to manage a firewall. I would like to share a connection between two interfaces using masquerading (example, or another). When I run those operations by invoking iptables ...
0
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2answers
396 views

How to redirect website in restricted network through ssh tunnel

I have established a reverse ssh tunnel into a restricted network to an aws server, i.e. to access it, I ssh into the aws server and from there I get access to the machine in the restricted network on ...
2
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1answer
14 views

Simple audio forewarding scheme

laptop(1) - wifi router(2) - wifi enabled PC(3) - speakers(4) (1) is a portable laptop, running some graphical interface. It has ssh access to (3) set up. (3) is an old machine, and thus running ...
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0answers
127 views

Purpose of UFW Allow All Rules in FORWARD chain?

What's the purpose of the allow all rules put into the FORWARD chain by UFW? They're currently messing up the 5 ACCEPT rules I've put in place underneath. Unless there's some specific valid reason ...
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0answers
77 views

WSL: Redirect links to host

As Windows is missing a nice twitter client I'm using WSL, with X11 forwarding to get Corebird running on my Windows 10 host. The question is: Is it possible to redirect the click on a link within ...
1
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2answers
50 views

Does OpenSSH >=7.2 support local-side tilde expansion for remote Unix socket forwarding

I am trying to forward a gpg-agent Unix socket to a remote machine. I have tried the following two versions of the remote forwarding command: A: ssh -vvv -N -R ~/.gnupg/S.gpg-agent:~/.gnupg/S.gpg-...
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1answer
987 views

Can't forward traffic from eth to TUN/TAP

I'm trying to forward traffic from a physical interface enp5s0 to a virtual one tun0. The goal is to make tun0 receive essentially all packets from enp5s0. First, I enable forwarding with a command ...
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0answers
440 views

IPv6 forwarding doesn't work

I have three Virtual Machines: A, B, C. Machine A and Machine C connected to each other through the B. Their config: A's IP: 2000::ffff:50a:b0b/120 C's IP: 2000::ffff:50a:d0d/120 Machine B has ...
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0answers
68 views

Two-way external server config with Postfix [closed]

I have a private network with an email server, basically for an intranet service. I also have a server I want to use as a relay to send and receive mail for the intranet mail server. I've seen many ...
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0answers
13 views

Forward ARP packets to an analyzing machine with pf (OS X), from en1 to en0

I have a machine that is outside a local network. The network is done via WiFi router. The machine is connected to one of the computers in network. So it doesn't see the network's ARP packets. I can ...
0
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1answer
238 views

trouble setting proper forwarding rules in `iptables` with custom ip address for network sharing

I am having issues setting up a bridge for my raspberry pi. My setup is: I have a laptop running fedora 27 workstation which is connected to the internet over wifi. I have a Raspberry Pi Zero W ...
0
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2answers
425 views

Iptables remote PC as gateway (all traffic forwarding)

Here is a problem: I have complete ssh access to two machines on the local intranet. On machine two quick and reliable internet access. I want to forward all outgoing traffic from machine PC1 via PC2 ...
1
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1answer
437 views

Forward traffic to virtual interface based on source IP address dynamically using iptables

I'm experimenting DNS server setup that reply different results based on source IP address. and the same time I need to dynamically change what interface external source ip should forward, eth0 ...
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0answers
41 views

how to to bridge two networks and packet alteration

I am trying to bridge two networks (i.e. 20.20.10.0/24 and 20.20.20.0/24). I have a machine (Ubuntu 16.04) connected to both networks and my ultimate goal is this machine to act as a bridge between ...
2
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0answers
457 views

Internet access in LXC container with nftables

I'm currently trying to give an LXC container internet access using nftables, but I don't seem to get it right whatsoever. The setup is the following: The host has a WAN interface (enp1s0) and a ...
1
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1answer
354 views

Problem with gateway server configuration on Centos 7

I'm trying to configure a host with Centos 7 and one network interface (eth0) to be a gateway. The problem is that Gateway can forward package, receive the answer but it fails with sending response ...
0
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2answers
941 views

Port forwarding using VPN client

I've already looked here and believe this is on the right track, though I still can't get it to work: Port forward to VPN Client? I have a vps, and on that vps I'm using openVPN. I have a connection ...
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0answers
47 views

Why response packets are not forwarded between interfaces?

I have the following situation on my host: veth5 10.0.0.3 o | ----------------- ...
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2answers
669 views

Sysctl Parameters accept_local and rp_filter Not Working on Dual-NIC Machine

root@host-3:~# uname -a Linux host-3 4.4.35-1-pve #1 SMP Fri Dec 9 11:09:55 CET 2016 x86_64 GNU/Linux root@host-3:~# cat /etc/debian_version 8.9 root@host-3:~# ifconfig eth0 Link encap:Ethernet ...
5
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1answer
4k views

IPTABLES: process a packet locally and send a copy to another host

I have a trouble configuring iptables to do this: some clients send messages to a server. I want that the host server processes the messages locally (host A, as normal) but that additionally for each ...
3
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1answer
704 views

What is kernel ip forwarding? related question

This question is related to the answer & comment in What is kernel ip forwarding? from @LawrenceC post1: So in the above example, if you have an internet connection on NIC 2, you'd set NIC ...
4
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1answer
8k views

Is net.ipv6.conf.all.forwarding=1 equivalent to enabling forwarding for all individual interfaces?

or it is the only way to enable forwarding for IPv6? /proc/sys/net/ipv6/conf# grep '' */forwarding all/forwarding:0 default/forwarding:1 eth0/forwarding:1 lo/forwarding:1 nat64/forwarding:1 tunl0/...
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0answers
98 views

CentOS packet capture device

I want to build a packet capture device for my home network (testing purposes). I have a spare computer with one NIC. I have CentOS. I've used TCPDump before so I plan on using that for now to see ...
2
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2answers
4k views

Port forward- Why is iptables with POSTROUTING rule required?

Supposing I have two servers: -->Server A has the IP XXX.XXX.XXX.XXX -->Server B has the IP YYY.YYY.YYY.YYY What I want is to redirect trafic from server A (port 80) to server B (port 80). A ...
0
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1answer
417 views

Postfix relay to one server from multiple users

I am trying to build a smart host in an Unix system, with Server app, Mail service and an Open Directory for local users. My question is if there is a way to use an email just for forwarding mail ...
3
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1answer
466 views

Is there any way to forward mail from the command line in Linux

I'm looking at the mail command which fires off Heirloom Mail. My procmail failed and it has 55 messages in the queue. I need to forward them out to another email and then process them manually. I'm ...
2
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0answers
230 views

Redirection of traffic from one computer to another

I have two computers on the same lan Comp A: 192.1681.151.15 Comp B: 192.1681.151.19 When I open Wireshark, for all traffic browsed on comp A, I would like Wireshark to capture traffic of comp A and ...
2
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1answer
170 views

Port forwarding for VirtualBox + Tor

I am a little confused, maybe someone can help me. I have configuration like: Router [External IP: 91.111.91.111] -> PC [Nat IP: 192.168.1.20] -> Virtual Machine as a Gateway (Whonix - Tor) [Nat IP ...
2
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0answers
271 views

Redirect traffic to specific website

I am trying to setup something like a captive Portal but get stuck. I have an embedded device which starts a Wireless Access Point. Now I like to forward all traffic to a website on the device. I do ...
3
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1answer
5k views

Limiting IP forwarding between certain interfaces/networks

I currently have ipv4.ip_forward enabled to route packets between multiple interfaces. I am now scaling up the system to 8 interfaces, but I want to limit the routing between interfaces/addresses. ...
4
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2answers
28k 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
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1answer
467 views

Best Graphics over X11 Forwarding

I am currently using Exceed to handle individual X windows being displayed back to my Windows machine and this works flawlessly. I'm using Windows as my Window manager, but I have also experimented ...
3
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1answer
969 views

Exim4 forwarding all emails of domain type to a specific email address

Recently I switched from shared web hosting to DigitalOcean VPS where I have Debian GNU/Linux 8 (jessie) running. In the web hosting I had the option to forward all emails (*@domain.com -- anything as ...
1
vote
1answer
1k views

lxc container <-> external internet, what I missed?

I have Ethernet on my machine (enp0s10) that connected to real network, and I have lxcbr0 Ethernet bridge which gather lxc containers. And I want to make available one of lxc containers. So I wrote: ...
0
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1answer
309 views

NAT for second interface on private network

I have the following configured for my two network interfaces. eth1 10.93.90.1 (Production Network) eth0 192.160.0.1 (Private Network/Labb Network) I want to configure eth0 with NAT so I can ...
3
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1answer
3k views

IP forwarding through ssh tunnel

The situation involves 3 machines: A Some laptop connected somewhere to the Internet via any mean B A server connected to the Internet through a standard ISP (static IP provided by dyndns: myserver....
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0answers
160 views

How to preserve mime type in CUPS forwarding?

I installed a small CUPS printer which accepts only application/postscript and converts this into a bitmap. Using a generic postscript printer driver I can directly print to this device without ...
3
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0answers
154 views

Can I use iptables to forward between interfaces without setting /proc/sys/net/ipv4/ip_forward?

Can I use iptables to forward between interfaces without setting /proc/sys/net/ipv4/ip_forward? I want a secure default of not forwarding anything and then specifying exactly what should be forwarded....
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2answers
1k views

Linux iptables ssh port forwarding (martian rejection)

I have a Linux gateway performing NAT for my home network. I have another network which I'd like to transparently forward packets to, but only to/from specific IP/ports (ie. not a VPN). Here's some ...
3
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0answers
190 views

SSH - Unable to access local forward from another host

I have a VPS with 2 public IPs (assume 1.1.1.1 and 1.1.1.2) I am trying to do a local tunnel to my router on my VPS bound to the second IP, and then access it via another machine. I do the following -...
3
votes
1answer
5k views

Pass a value for an input prompt

I do unzip my.zip and if files already exists it asks replace myfile.ext [y]es, [n]o, [A]ll, [N]one, [r]ename: How can I force input for when the command prompts for input? I am aware unzip may have ...
1
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1answer
586 views

iptables inside bridge

if i have: eth0 (no address) wlan0 (no address, providing wifi-hotspot by 'hostapd') br0 (local IP, bridging eth0+wlan0) eth1 (public IP, providing internet to above by net.ipv4.ip_forward=1) ...
5
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1answer
943 views

unable to connect to forwarded port over ssh

I have two servers. Server 1 has access to an Oracle instance on a server I have permission to hit but not login to via SSH. I would like to use SSH port forwarding to connect from server 2 to server ...
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0answers
804 views

openvpn: iptables not forwarding

I have the following topology: And I'm following the iptables rules listed on https://community.openvpn.net/openvpn/wiki/BridgingAndRouting Here's the output of iptables -L -v Chain INPUT (policy ...