4
votes
2answers
31 views

Redirecting loopback traffic through a router

For some tests purposes, I am running multiple socket-based applications on one machine and want to simulate "real" network conditions between them. I thought the simplest would be to redirect all ...
1
vote
1answer
27 views

iptables routing

I believe this question has been answered a 100 times before, but I'm almost sure that I'm searching into the wrong direction. My desired setup is the following: I have a virtual host using KVM and ...
1
vote
0answers
21 views

ISC DHCP Server - A Client's Uplink Is Not Working

Running a DHCP server, client(s) does not have up-link (0Mbps) and has a downlink (50Mbps.) I am setting up a gateway/router on a PC running Debian Wheezy with ISC-DHCP. I have 1 WAN (eth0) and 2 LAN ...
2
votes
0answers
39 views

Transparent Proxy

I am setting up attempting to set up a transparent proxy on CentOS using Squid. So far I have managed to filter the content and get it working perfectly. The only issue I am having is getting a form ...
1
vote
0answers
53 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
1answer
68 views

Setting up a gateway between two subnets on the same physical network

I need to configure a DHCP-enabled network (192.168.2.) on a physical layer where resides an already existing network (192.168.1.) with static IPs. I have a Debian 7 server with two interfaces (server ...
3
votes
0answers
40 views

Packets do not cross IP tables Postrouting when originating from an external IP

I'm trying to reflect traffic from the internet to an internal device that I only want to have local access. I have a host in my DMZ that I'm trying to DNAT traffic to this internal device, and SNAT ...
1
vote
1answer
52 views

Iptables not forwarding. Input instead

I have set up iptables on my ubuntu headless server: iptables -S -P INPUT ACCEPT -P FORWARD DROP -P OUTPUT ACCEPT -A INPUT -s 10.1.3.90/32 -i eth0 -j LOG --log-prefix "INPUT: " -A INPUT -i eth1 -j ...
1
vote
1answer
49 views

CentOS Traffic Filter

I am trying to use Squid to filter the traffic flowing through the network. I am also trying to make this system transparent. My network setup is like so: Router -> CentOS Machine -> The rest ...
1
vote
0answers
248 views

Port redirection on loopback with IP other than 127.0.0.1

I want to redirect port 80 on the loopback network interface so that accesses to that port actually go to port 8080. I tried using the following command, but it only works if the application is ...
5
votes
1answer
151 views

Skip routing via `lo` interface for outgoing packets

Introduction I have following load balancing configuration: 10.0.1.31 - lb 10.0.1.35 - virtual IP 10.0.1.32 - node1 (tomcat + mysql) 10.0.1.33 - node2 (tomcat + mysql) I'm using keepalived which ...
0
votes
4answers
75 views

Linux routing tables

I'm trying to learn Linux routing tables and ran into bit of snag. In the example below I'm not sure what is happening. My understanding is 0.0.0.0 means that for line 1 and 2 any packets outside of ...
1
vote
1answer
77 views

tcp/ip - trigger action or event after period of no network activity on certain port(s)

Is it possible, perhaps using iptables or one of the wrappers/frontends to iptables, to trigger an action or run a script after a certain period of time has elapsed with no network activity on a ...
0
votes
3answers
67 views

iptables rules - input and output

I'm new with Linux and iptables. I have a Ubuntu Server distro (12.04) on a PC which has 2 network interfaces (eth0 and eth1). I also have 2 laptops, one is plugged to eth0 and the other to eth1. ...
1
vote
0answers
348 views

How to redirect tun SSL VPN through HTTP CONNECT proxy, using iptables?

I use a VPN under SSL solution (Firepass) on Android. VPN opens an SSL connection on port 443 of remote VPN server. My mobile carrier doesn't allow direct connections on port 443 but allow SSL ...
1
vote
1answer
192 views

High performance routing with high churn ruleset. What approach is most likely to scale to C10K and beyond?

I've been asked to create a high throughput router using PC / server hardware. I'm modestly familiar with pf, iptables, and tc, but I've never had such high churn and so many rules. I hope you can ...
1
vote
1answer
293 views

Route HTTP traffic thorugh different interface

I have my normal eth0 interface and an setup ppp0 interface, the problem I have is that I want to exclusively route all HTTP/HTTPS traffic through the ppp0 interface and everything else through the ...
0
votes
0answers
25 views

Routing Application through different network interfaces [duplicate]

I have two interfaces on a server, let's call them eth0 and eth1. The underlying server is running CentOS 6.5 I would like to be able for some application to use eht0 while some others use eth1. ...
0
votes
1answer
233 views

iptables Port Forwarding — no service with the port

I have setup a network as in the image below: Firewall (FW) running CentOS 6 has two physical interfaces with subinterfaces: eth0:2 — 10.100.1.78/25 eth0:3 — 10.100.1.79/25 eth3 — 192.168.0.21/24 ...
1
vote
0answers
31 views

How to send packets coming from a second router on a particular port back to the router, using iptables not a route

I have a Linux server which runs a particular service listening on a single TCP port. The Linux server connects to the internet using a PPP connection and also acts as router for a local network using ...
0
votes
0answers
576 views

Use iptable do redirect all the HTTP traffic to localhost

I use a Linux machine as WLAN Router with the help of hostapd and udhcpd. There's also an Apache web server installed on the same machine. Now I want to redirect all the traffic which comes through ...
1
vote
1answer
131 views

Managing iptables for home lan routing

I have a LAN at home. One Netgear router - 192.168.0.1 connected to the internet. One Macbook - 192.168.0.10 (connected to Netgear router) One PC with Kali Linux - 192.168.0.20 (connected to ...
0
votes
1answer
121 views

Squid not forwarding my packets proxied from iptables on router

I am trying to make openwrt's iptables from my router to direct to my squid proxy on my machine (since there is no enough space in router's flash memory) but even if I have my squid config ok ( ...
1
vote
0answers
255 views

iptables one IP through another network interface

This question is very similar to what I am trying to do: iptables --set-mark - Route diferent ports through different interfaces However I attempted to follow the answer but I was unable to make it ...
2
votes
1answer
113 views

Mark packets between machines (client and router)?

Can I mark a packet on the client's OUTPUT chain and add an iproute policy on the router to route them via a specific gateway? This what I tried to do, but it isn't working. My client's mangle table ...
2
votes
0answers
204 views

SNAT problem in iptables

I am trying to reroute traffic from specific devices in my house over openvpn. For this, I've created an OpenVPN tunnel between my house wifi router and my server. Here is my setup: Wifi router's ...
8
votes
1answer
2k views

Linux as router with multiple internet providers

Linux as router: I have 3 Internet providers, each with its own modem. Provider1, which is gateway address 192.168.1.1 Connected to linux router eth1/192.168.1.2 Provider2, gateway address ...
1
vote
2answers
257 views

iptables: what the difference between filter and mangle

I am using iptables to to mark the package and want to route based on the marks. First I added the ip rule: sudo ip rule add fwmark 1 prohibit (The "prohibit" is just for test, I will change it ...
1
vote
1answer
285 views

What does the route Dest: 123.123.123.123, GW: 0.0.0.0 mean?

I have a route table: Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 123.123.123.123 0.0.0.0 255.255.255.255 UH 0 0 0 ...
1
vote
1answer
832 views

Copy/Mirror traffic to WAN interfaces without “iptables tee” support

I want to copy every outgoing packet to other WAN interfaces but my iptables (v1.2.7) doesn't have TEE target support. I wonder if there is another way (maybe using iproute2 or ebtables) to copy every ...
4
votes
2answers
160 views

Is it possible to set-up a VPN in such a way that I disconnect from the Internet if it goes down?

How can I set-up a VPN so I loose connection to the Internet if it goes down? I use Ubuntu and have used the network-dialog to use a VPN; but if the VPN goes down, it just switches to the non-VPN ...
3
votes
1answer
109 views

What are the requierements to sniff UDP packets in a Wireless Ad-Hoc network?

In a wireless Ad-Hoc network, I have two computers which communicates in UDP together from 192.168.1.3 to 192.168.1.5 I have a third computer (192.168.1.6) which wants to listen to the packets which ...
1
vote
1answer
581 views

How do I route different users over different OpenVPN tunnels in Linux?

The setup: I have multiple, static-key OpenVPN client/server configurations, labeled "client1", "client2", and "client3" with server/client IPs 10.10.1.1/10.10.1.2, 10.10.2.1/10.10.2.2, and ...
2
votes
1answer
197 views

Linux nat/iptables configuration for a chain of peer-to-peer links

I have an experimental setup, of 4 Linux (CentOS) machines: All 4 machines are internally connected using different networks and can ping eachother directly connected interfaces. However only PC4 ...
1
vote
1answer
2k views

Redirect Packets from ppp0 interface to ethernet interface in linux

My question is similar to this question, however with some change. I have a PPPoE connection on my Linux Machine (CentOS kernal 2.6.32) as a client, so that when I setup this connection, another ...
4
votes
2answers
436 views

Why can I reach a different interface's IP address?

I'm wondering about this, and I can't seem to find an explanation on the internet. I have a linux gateway which has multiple interfaces: eth0: external ip eth1: 172.16.1.1/24 eth2: 172.16.2.1/24 ...
2
votes
1answer
215 views

PPTP server with NIC aliases

I have set up a VPN on a VPS Server using PPTP. I have one NIC with two aliases. eth0 eth0:1 eth0:2 The 3 interfaces have public addresses. eth0 is a French IP, eth0:1 is UK, and eth0:2 is ...
9
votes
2answers
18k views

iptables --set-mark - Route diferent ports through different interfaces

Short story, 3 interfaces, eth0 (LAN), eth1(ADSL), eth2(4G). eth0 -> eth1: Works (ports 80, 443, 4070) eth0 -> eth2: Doesn't happen This is a graphical representation of the idea: Port 80 & ...
2
votes
1answer
801 views

Allow IP packet forwarding from LAN to modem via router

In short: I'd like to be able to telnet to my modem from my PC via my router. There is a simple home router on 192.168.33.1. It is running OpenWrt. It has the following interfaces defined: br-lan ...
1
vote
1answer
307 views

Firewall/routing rule in Centos for this setup

I have two ethernet interfaces, namely eth0 and eth1. I want to implement an advanced routing rule but I am totally new to firewall/routing rules in CentOS. Here is what I am trying to do: Both my ...
4
votes
1answer
316 views

Using source routing (LSRR) - any ideas?

What I want to do is conceptually very simple, but I can't find any information or help about how to go about doing this. Basically, I want to configure my networking to use source routing (LSRR). ...
3
votes
2answers
502 views

policy routing problem with load balanced ppp connections

This my setup using Debian 6.0.6. It's role is a proxy server and a load balancer using eight 3G modems. First and foremost: Whenever a ppp connection dials it takes over the default gateway which ...
1
vote
1answer
2k views

iptables forwarding and routing

In fact, this question is about openwrt and CoovaAP, but I guess it's the same in other linux distributions. I've two interfaces, a "wan" and a "wlan" interface. Is there by default any filter, ...
1
vote
1answer
491 views

How to provide a “guest LAN” on one ethernet device

I have an always-on machine running Debian/Squeeze with a couple of ethernet ports (it's doing various serverish jobs, including DHCP) and a LAN on each. eth0 is on 192.168.7.* and has access to the ...
1
vote
1answer
2k views

Redirect http using iptables for an ip range

I have a range of ip addresses (10.13.13.10-19) that I want to redirect all outgoing http traffic to an internal webserver. So if someone in that range tried to access any site, the html from my ...
3
votes
1answer
561 views

Routing through iptables

I have this vpn client that touches the routing table and then keeps watching it to exit if it gets touched. It is the kind of setup needed for an endpoint, such as a laptop. I want to use a small ...
2
votes
2answers
541 views

Having trouble with packets not making it into Fedora 16 Apache

Background: I haven't done anything with iptables in a few years... I have Fedora 16 running in a VM on VMWare, with my firewall (TomatoUSB) port forwarding to the VM. VM is at 192.168.1.155. I know ...
1
vote
2answers
194 views

How can I use the same IP from the Internet and intranet?

I have an Ubuntu firewall box (Alma), at the office, with a web server on it. It looks like this: [Internet] <-> [DSL Router] <-> [Alma] | ...
3
votes
2answers
654 views

Need help with routing

I have set up a Ubuntu server, that I want to use as a router for my local office. The problem is, that I want to make 2 VPN connections, to remote branches, and then I want to route all traffic to ...
9
votes
3answers
15k views

Output traffic on different interfaces based on destination port

My question is basically the same as Only allow certain outbound traffic on certain interfaces. I have two interfaces eth1 (10.0.0.2) and wlan0 (192.168.0.2). My default route is for eth1. Let's say ...