All Questions
47
questions
0
votes
2
answers
1k
views
Route traffic on different ports through different network interfaces
My situation is this: I’m setting up a server running at home (Ubuntu Desktop 22.04.3 LTS) to run an email server and a few other online services. As we all know, for my email to work reliably and not ...
- 45
0
votes
0
answers
342
views
Use TPROXY feature of iptables with Ubuntu 22.04
I'm trying to use the TPROXY feature of iptables.
For example :
iptables -A PREROUTING -t mangle -p tcp -i eth0 -j TPROXY --on-port 5000 --tproxy-mark 1
This feature works perfectly on Ubuntu 16.04 (...
- 1
0
votes
0
answers
183
views
Route traffic from VPN to web proxy
I'm struggling for days to do this:
I've got an Openvpn installed on a ubuntu server, I want this traffic to be routed to a web proxy (socks5), so it will look like this :
Device->VPN->Proxy->...
- 1
0
votes
0
answers
352
views
PBR routing doesn't work on Ubuntu 22.04 Server
I'm attempting to configure my server, but it's proving to be impossible. Thus, you are my last hope!
To provide some context, my virtual server (Ubuntu 22.04 server TLS) has 3 network devices ...
- 1
1
vote
2
answers
2k
views
Route all traffic from one server to another
I have two servers.
First one is from a local datacenter. OpenVPN is installed on Ubuntu 22.04. Clients connect to this server and get an IP from 10.8.0.0/8 pool. Clients are configured to redirect ...
- 181
-1
votes
1
answer
140
views
How to read and alter packet info when forwarding
I have two laptops running ubuntu(both 20.04.4 LTS x86_64) and im trying to use one as a router(lets call them laptop1 and laptop2 and laptop2 is acting as a router). So far ive used the ip route ...
0
votes
0
answers
130
views
How do I get ssh to start working?
I turn an unused laptop into an Ubuntu server and everything was working great. I connected to it through ssh on my Windows 10 computer and was able to set up and access Nextcloud to upload all my ...
- 1
0
votes
0
answers
436
views
How to have a same static IP address in all the networks
Imagine, I have an application at office which is bound to use 10.x.x.x IP address once it is installed. The gateway of this address will be 10.x.x.1 and this IP is set as static.
So, when I move the ...
1
vote
1
answer
1k
views
Prevent routing of DHCP traffic
First, I'm aware that similar questions to mine have been asked elsewhere (I've read many of those posts!) but I've not been able to figure out a solution to my problem, so I'm asking for help.
My ...
- 11
0
votes
2
answers
82
views
Skip route table
I want to create a VM VBOX Ubuntu to be a gateway in my home lan to route to my enterprise VPN.
The problem is that my VPN when is stablished, create a route per route entry with metric 1 to be routed ...
- 1
3
votes
2
answers
1k
views
Can someone explain interactions between iptables, nftables and bpf?
I'm on Ubuntu 20.10 trying to do some routing config for my virtual network, and I'm confused about the interactions between the 3 main types of firewall technology used in modern Linux distros, ...
- 1,286
0
votes
1
answer
514
views
What do these iptable rules mean?
These:
sudo iptables -t nat -A POSTROUTING -o tun0 -j MASQUERADE
sudo iptables -A FORWARD -i tun0 -o wlan0 -m state --state RELATED,ESTABLISHED -j ACCEPT
sudo iptables -A FORWARD -i wlan0 -o tun0 -j ...
- 21
1
vote
1
answer
572
views
Network routing and port forwarding problem
I have 2 networks (graph in link below)
A: 10.0.0.0/24
B: 192.168.1.0/24
In network A, all devices are connected via a switch. Some devices provide certain services such as ssh or access to a database ...
1
vote
1
answer
1k
views
Dual NIC Configured as Router with NAT
I have a PC running Ubuntu 18.04 and am attempting to configure the two GbE interfaces as a gateway/router. I've referred to some related questions and attempted to follow guides such as this one: ...
0
votes
0
answers
164
views
Can not ping from one node to another while both nodes connected via an ethernet cable
I have two ubuntu machines each with two physical NICs.
I am trying to create a private network between two of them connecting of one node's NIC with the other node's NIC.
In Node 1 when I run
...
- 11
0
votes
0
answers
201
views
Udp Routing with 2 ports
I'm trying to pull udp stream to my ubuntu 14.04 and can't handle routing.
I'm having 2 ports
1. is port with internet connection(local adress)
2. is port with udp multicast streams with dynamic ...
- 193
1
vote
0
answers
132
views
Ubuntu as router: Network Layer packets not reaching WAN
I've got most of it working, but can't quite close the loop.
I'm running Ubuntu 18.04.2 on my Raspberry Pi 3. I'm trying to use it as a wireless access point, but not as a bridge. I followed this ...
- 11
4
votes
0
answers
862
views
Enable packet routing from network interface eth0 to bridge interface
I have a Ubuntu server connect to LAN 10.1.200.21/24 (bond0), and an Macbook connect to LAN 10.1.200.50/24 (eno1)
There are another bridge create by brctl addbr br0 in Ubuntu 10.3.100.1/24, and there ...
- 41
1
vote
0
answers
76
views
Port activity after applying iptables
I've applied a rule in the iptables
(Ubuntu x64 18)
sudo iptables -t nat -A OUTPUT -p tcp --dport 64080 -d 172.31.132.86 -j DNAT --to-destination 149.154.167.50:80
sudo iptables -t nat -v -L OUTPUT ...
- 171
0
votes
1
answer
40
views
3 -> 1 routing issue
I've had this working before, but I can't get it right on a new machine. I have the following setup on a ubuntu install as a router.
192.168.2.0/24 p34p1 wifi1 -------------|
192.168.1.0/24 p33p1 ...
- 195
1
vote
1
answer
4k
views
iptables setup for routing
I want to setup my ubuntu computer to route packets. Therefore I've read several tutorials which always had many rules to add to iptables.
I finally found out, that the only rule needed (given that ...
- 113
1
vote
0
answers
117
views
How can I improve this iptables
As a training, I'm trying to install a server with ESXi,
On this ESXi, I have a first ubuntu 16.04 VM that will be the firewall between WAN and LAN.
So the host machine IP is 192.168.1.25 and the ...
- 111
1
vote
0
answers
354
views
Ubuntu 18.04 server with 2 NICs
I am running a Ubuntu 18.04 server with 2 NICs both with static IPs as shown in the yaml below.
NIC 1 (enp5so) is connected to a router on 192.168.46.1. Both NIC's are functioning fine with NIC 1 ...
- 11
1
vote
0
answers
462
views
how to create multiple wan connection to single lan?
I am trying to have 2 connections simultaneously using DSL, my topolog is has given below:
My LAN and WAN PCs are ubuntu 14.04 virtual machines running on 2 different Windows PCs.
LAN-eth1(192....
- 11
1
vote
1
answer
3k
views
fwmark routing policy with netplan
I'm migrating a legacy Debian setup to a new Ubuntu setup. I have previously set, in /etc/network/interfaces:
post-up /sbin/ip rule add fwmark 1 table table.tunnel
pre-down /sbin/ip rule del fwmark 1 ...
- 13
1
vote
1
answer
533
views
How to connect four computers together without using any external device?
I need to connect four computers serially. The topology is given below.
c1<--->c2<--->c3<--->c4
I have multiple ethernet cards in c2 and c3 computers. I don't need ...
- 13
-1
votes
1
answer
2k
views
How to route VLAN subnetworks to my DSL ppp0
I have a fiber optic connection through a Huawei ONT device. (I don't know the exact model) The device mode changed to "modem" by the ISP so I should connect through PPPoE. (I have the ...
0
votes
0
answers
3k
views
Port forwarding from OpenVPN Client to Public Internet
I need to forward port 44444 of my VPN client to the public internet with my public IP on port 44444, how i can do this?
The VPN Server is mine and I have root access.
Example how i can do this?
...
- 21
2
votes
0
answers
986
views
How can I forward all incoming traffic from the local network to a VPN tunnel?
The router is forwarding all traffic from an IP range, that goes towards outside the local network, to this host (that is intended to be a VPN concentrator). Using tcpdump on the host verifies this.
...
- 121
0
votes
0
answers
997
views
Ubuntu as a router on the same subnet
I am having an Ubuntu VM on VMware Workstation 12. I need to use this VM as a router to route traffic between a hardware (eNodeB) and another virtual switch, which are both on the same subnet (192.168....
4
votes
2
answers
29k
views
Route all traffic of a machine through another within a subnet?
I have two computers, both running ubuntu 12.04 64 bit. I need to route traffic of one computer through the other.
computer A: 192.168.1.3 (eth0)
computer B: 192.168.1.7 (eth0), 192.168.1.5 (eth1), ...
- 381
1
vote
0
answers
45
views
Headless server no longer routing after minor fiddling with DNS and DHCP
Apologies up front for any spelling errors or anything, but I'm forced to write this post on my phone.
I'm running ubuntu 16.04.2 LTS headless which I also use as a router for my LAN. Typically I ...
- 11
1
vote
0
answers
213
views
What's the best way to work with multiple IP address simultaneously?
I learned how to add multiple IP address, based on the Debian instruction here:
Multiple_IP_addresses_on_one_Interface
and thread:
how-do-i-add-an-additional-ip-address-to-etc-network-interfaces
# ...
- 111
5
votes
1
answer
1k
views
IPv6 gateway computer - How to set up routing?
I'm trying to use a linux VM as an IPv6 internet gateway for another VM.
I have a server installed for which I received the ipv6 prefix 2001:abcd:1234:5678::/64 (Note I edited the prefixes for privacy ...
2
votes
2
answers
4k
views
How to bypass VPN connection?
My router (192.168.1.1) connected to the internet via PPPoE. Server (192.168.1.20) has OpenVPN client installed and all other computers get 192.168.1.20 from DHCP as default gateway. My IP-phone doesn'...
- 41
3
votes
1
answer
15k
views
What is the UH flag in routing table
I'm using an Ubuntu machine as a server and it has two network interfaces. One is the 10.10.10.0/ 24 range and the other is 192.168.0.0 /24 range. I was trying to bridge these network interfaces as ...
- 143
1
vote
0
answers
277
views
14.04 LTS / Routing with 2 WAN Lines ... on Dom-0 Xen host drives me nuts
Short note:
Well I think I might have a solution but need to prove it first.
Regarding the NAT on the Hardwarerouters to each WAN-line seem just to do NAT for its own subnet, so I will simply need ...
- 41
0
votes
1
answer
617
views
How to redirect URL:PORT traffic to multiple external IP:Port?
Currently, I'm using iptables to redirect incoming requests for "website.com:27015" to "xx.xx.xx.xx:27015". Problem is, since iptables redirects via the port 27015, I can only redirect to one single ...
- 269
0
votes
1
answer
757
views
linux gateway / firewall IPtables config
The KVM host is acting as a gateway / firewall for all of the virtual machine's it runs.
It has a /26 public IP space configured on LAN interface em1: 1.1.1.1/26
It has a /30 rfc1918 IP configured on ...
- 1
5
votes
0
answers
10k
views
Using Ubuntu 14.04 as router with iptables, clients can't go online. Probably DNS issue, iptables setting needed [closed]
CORRECTION 3: SOLVED! I needed to add the the official DNS server of my departement's VLAN as DNS to the clients.
I've read through a large number of posts about iptables issues when using Linux as ...
- 150
26
votes
4
answers
31k
views
persist port routing from 80 to 8080
I use amazon EC2 instance which works via ubuntu. By default according security restrictions I can't bin my application to port 80, so I just bind it port 8080 and then set routing redirect from port ...
- 405
2
votes
1
answer
1k
views
help understanding iptables router script and error
Hello I have this routing script that I'm using which runs when all the network interfaces are up:
#!/bin/sh
PATH=/usr/sbin:/sbin:/bin:/usr/bin
#
# delete all existing rules.
#
iptables -F
...
- 325
14
votes
1
answer
51k
views
Forwarding traffic between 2 interfaces
I have 2 VLANs connected to a 'router'. All the machines can ping other machines within their own VLAN and the router. The router can ping all of the machines. I am trying to get machines to talk to ...
2
votes
1
answer
6k
views
Forward TCP Connections with Iptables
I receive connections to my server from several ip addresses I want to route these connections just like rinetd does but based on the ip the connection is coming from to connect to a specified host.
...
- 487
2
votes
1
answer
2k
views
OpenVPN - Routing issue
Server: Ubuntu 11 (Openvz VPS)
Client: Windows 7
Issue:
clients connect successfully to VPN, but loss of internet access once
inside the VPN.
Facts:
Everything mostly defaults
Is a routing/...
- 21
2
votes
0
answers
699
views
iptables, forwarding between interfaces
I'm trying to setup a router using iptables.
But, after a lot of examples I've tried, I can't get anything to work.
My idea is to setup a box in between my Cisco and the main switch for firewall, ...
- 21
2
votes
1
answer
3k
views
Weird issue with iptables redirection
I am trying to redirect all incoming traffic on UDP port 5060 to port 56790, and all outgoing traffic from 5060 to the port 56789. I used these iptables rules:
iptables -t nat -I PREROUTING -p udp ! -...
- 675