My Ubuntu Box has 3 interfaces. eth0 (Internal 192.168.1.0/24)eth1 (External ISP DHCP)eth2 (External ISP Static IP)I need the outgoing traffic to internet for 1 of the internal pc (192.168.1.10) to only go only go through eth2
View 4 RepliesI have a linux router with 2 physical ISPs and a VPN tunnel that all my traffic passes through. I would like to setup a rule to redirect all traffic from one internal IP address (10.0.0.x) through the physical link only. My current script is as follows.
iptables -F
iptables -X
echo 1 > /proc/sys/net/ipv4/ip_forward
[code]....
My goal is to do something similar to the mangle on the tor traffic, but for an entire host.
I need to configure iptables to block incoming traffic (except specific ports), but allows all outgoing traffic.
I am able to block incoming traffic, but doing so also prevents outgoing traffic (tested by telnet [URL] 80)
The following was used:
iptables -A INPUT -p tcp --dport ssh -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j ACCEPT
iptables -I INPUT 1 -i lo -j ACCEPT
iptables -A INPUT -j DROP
Also, even allowing NOT SYN requests still prevents outgoing traffic.
iptables -I INPUT 1 -p tcp ! --syn -j ACCEPT
Another point:
# modinfo ipt_state
modinfo: could not open /lib/modules/2.6.18-028stab070.14/modules.dep
How to install ipt_state module on ubuntu?
it�s been several years since i played with iptables. I have setup like this:eth0 is the only physical device on box and eth0:0 is aliased. Traffic going out of the box to internet uses eth0eth0 116.55.58.1eth0:0 116.55.58.2I have a service listening on port 80 on 116.55.58.2Lets say my client connect to 116.55.58.2:80 through 116.55.58.1 , how do I force (mangle you name it) with iptables that the outgoing source address will be always 116.55.58.2?
View 1 Replies View RelatedThe task I am trying to complete is the virtualization of an IPv6 router created using two fedora machines. Here is the physical setup I have now...
PC1:eth0 <------> network
PC1:eth1 <------> PC2:eth0
PC1:eth2 <------> PC2:eth1
PC1 runs radvd to provide router advertisements to the network and a DHCPv6 server for stateful addresses.Each interface is configured on a separate subnet. PC2 runs a DNS server on eth0. PC2:eth1 is used as an IPv6 client for testing purposes. The connections from PC1 to PC2 are just crossover cables.I've created virtual machines of both PCs and have created 4 virtual adapters on the host machine for each of the local-only interfaces.Now I have this:
PC1:eth0 = HOST eth0
PC1:eth1 = HOST vboxnet0
PC1:eth2 = HOST vboxnet1
[code]....
I have a DELL running CentOS 5.4 with 2 active NICs, one with an external IP address (eth0) on 123.456.78.9 and another that is connected to our internal network (eth1), 192.168.2.x. When I reboot the server, everything works glowingly. External traffic is correctly routed over the external interface (eth0) and internal traffic over the internal interface (eth1). After some random amount of time, a couple of hours and sometimes a couple of days, all traffic starts getting routed over our internal network, so DNS requests fail, internet pages don't load, smtp connections fail, etc.
I'm assuming that everything that's not headed for our .1, .2 or VPN internal networks would go out the external interface. And why this works for a period of time and then stops working is beyond me. And when external traffic starts going over the internal interface, I just reboot and it starts working like it's supposed to again.
My ISP has given me 3 IP addresses to use for the internet (76.148.200.3, 76.148.200.4 and 76.148.200.5).
If I do a "wget whatismyip.com" or netcat into another server, I am appearing as 76.148.200.3.How do I change my route (command line) in linux to route internet traffic through 76.148.200.5?
Code:
# This file describes the network interfaces available on your system
# and how to activate them. For more information, see interfaces(5).
# The loopback network interface
auto lo
code....
I have eth0 and tun0. tun0 is a VPN tunnel going over eth0. Everything on the other end is setup and working fine, when I type Code: traceroute 4.2.2.1 I see my the ping is going over 192.168.2.99 (eth0). When I then type Code: route add -net 4.2.2.1 netmask 255.255.255.255 dev tun0 traceroute 4.2.2.1 I see ping is going over 10.8.0.1 (tun0) instead of eth0, so that is working
What does not work however is when I do Code: route add -net 0.0.0.0 netmask 0.0.0.0 dev tun0 traceroute 4.2.2.1 I get no ping! I believe the problem is because all traffic is routing over tun0, which means even the VPN tun0 needs to go through eth0, it can no longer do this. Is there a way around this where I can route everything except for 114.77.31.26 (which is my VPN gateway for tun0)?
today I tried to configure a network route to a host for testing my network interface. Code: route add 192.168.1.15 eth0 As I have to eth interfaces and both interface got their IP from DHCP (192.168.1.11 and 192.168.1.12) and are in the same subnet, I shut the other interface down:
Code: ifconfig eth1 down Then I tried to test the interface by doing a ping to 192.168.1.15.
Problem: When I unplug the cable from eth0 (and eth1 is still plugged) the ping still works. Somehow my linux (it's debian) powers up again eth0 and pings over this port.
How can I stop my linux doing this. I just want to have the route added only on the one interface - not the other. Is it maybe some case of a default-gateway?
I have 3 network interfaces on my Linux Router :
Interface - Gateway - Type
Code:
br0 - 192.168.0.1 - Internet
eth2 - 192.168.1.1 - LAN
tun0 - 10.0.0.2 - VPN (via br0)
What I'd like to do is to route all TCP packets coming from eth2 to tun0 where a VPN client is running on 10.0.0.2. If I delete all default routes and if I add a new route to tun0 like :
Code:
route del default
route add default gw 10.0.0.2
Everything is fine, and everyone on eth2 can reach the Internet using the VPN access. Now the problem is that my VPN client does not allow any other protocols other than TCP. And I also want to allow VPN access only to eth2, no other LAN nor the router itself. use iptables to filter any TCP packets and mark them, so they can be sent to tun0, while any other packets can reach the Internet via br0 (192.168.0.1). I found on the Internet that we can mark packets before they get routed. Using the following commands :
Code:
iptables -t mangle -A PREROUTING -j MARK --set-mark 85 -i eth2 -p tcp --dport 80
ip route add table 300 default via 10.0.0.2 dev tun0
ip rule add fwmark 0x55 table 300
First of all, --dport 80 never work... :/ I wanted to filter TCP 80 packets coming from eth2, but none of them seems to be HTTP packets... oO (very strange...). Nevermind, I decided to forget about the --dport option. I use the "iptables -L -v -t mangle" command to see how many packets are marked, and it is working fine, all TCP packets coming from eth2 are marked. Now the problem is that none of them are routed to tun0 they are all respecting the "route -n" rules... and not the "table 300" rule I have created.
I have a strange iptables issues. I have just built a new Debian install and starting adding some real basic rules (see below) the problem seems to be that the localhost itself can't get any returning traffic. That is, it seems to be allowed outgoing traffic but not the connected, returning traffic. Ordinarily allowing Established Connections would resolve this, see the rule below, but it hasn't. Why this doesn't work. Removing the last DROP in the INPUT chains obviously makes the traffic work!
iptables -A INPUT -m state --state ESTABLISHED,RELATED -j ACCEPT
iptables -A INPUT -j ACCEPT -p tcp --dport 22
iptables -A INPUT -j ACCEPT -s x.x.x.x
iptables -A INPUT -j ACCEPT -s x.x.x.x
iptables -A INPUT -j ACCEPT -s x.x.x.x -p tcp --dport 80
iptables -A INPUT -j ACCEPT -s x.x.x.x -p tcp --dport 8080
iptables -I INPUT 1 -i lo -j ACCEPT
iptables -A INPUT -j DROP
I have a couple of interfaces in a Fedora 14 box:
eth0: internet provided by an adsl router
eth1: LAN
I set up system-config-firewall to masquerade all outgoing traffic in eth0, as I did in other Fedora 13 boxes, but it seems it doesn't work. It sets to 1 /proc/sys/net/ipv4/ip_forward and also set the appropriate rules in iptables. But all traffic is blocked from the LAN to the Internet. "ping www.google.com" works in the Fedora box, but doesn't work in the LAN computers using the F14 IP as gateway. I have another F13 computer elsewhere configured this way and it works fine. But this one has Fedora 14.
I use a server with 3 nics,
eth0 192.168.2.100 (internal Web, Mail)
eth1 192.168.3.100 (Default Gateway nic for clients)
eth2 192.168.3.110 (should be default Gateway for all outgoing traffic not belonging to 192.168.2.100 and 192.168.3.100)
They are all on the same machine
i cannot set eth1 or eth2 as default gateway, as outside requests to eth0 would be handled in a false manner (somehow)
is there an easy iptables-rule to say, that outgoing traffic, not belonging to my networks can be redirected to a specific NIC (eth2)?
I have a Linux IPTables firewall on Centos 5.3.It has one physical interface to the internet and 2 internal interfaces to a DMZ and TRUSTED zone respectively.There are 10 virtual interfaces linked to the physical public interface.Emails are being sent from my server in the DMZ out to the internet, but it is being shown as coming from the firewall IP address.It must show as coming from one of the virtual interfaces.
View 4 Replies View RelatedI do $ sudo iptables -A INPUT -p TCP -i eht0 --destination-port 80 -j ACCEPT
and then $ sudo ufw enable but I still get no internet traffic. What is wrong? Shouldn't opening port 80 to TCP allow the packets though my firewall?
I've succesfullly connected to my vpn with kvpnc, but none of my traffic is going through the vpn! I dont know how to route traffic to the vpn. for instance, when I go to whatsmyip.com it still has my previous ip.
View 1 Replies View RelatedI've noticed recently that a lot of outgoing internet traffic is generated by my laptop (running Ubuntu 10.04 - 64 bit). This wasn't the case previously. I only found out because my wireless broadband traffic allowance suddenly was used up very quickly. I've installed ntop to try to find out where all this traffic is going to.
I did find that there were a very high number (at one stage over 11.000) of active TCP/UDP sessions (see attached screenshot). Although the traffic generated by each is only small (about 100 bits/bytes - not sure what) multiplied by thousands, makes a fair bit of traffic. I wonder if I've got some kind of a virus/bug or do I have a configuration problem with my laptop?
I have a need to make a rather odd filter in tcpdump- I would like to capture only all those packages on interface eth0, that are outgoing(in other words from IP 192.168.1.1, which is IP for eth0 in this computer) and doesn't have src MAC address 11:22:33:44:55:66. However, fallowing command says, that syntax is wrong:
Code:
tcpdump -n -p -i eth0 src host 192.168.1.1 ether src not 11:22:33:44:55:66
Is this possible? If yes, then what is the correct command?
OS : CentOS 5.3 64bit How to trace incoming and outgoing network traffic for a give user? User 'A' logs in to the system and does various network connectivity As root user need to find what are the outgoing and incoming connection that are related with user 'A'. basically need to check the connection flow. netstat will show ESTABLISHED, LISTEN etc.. need something like tcpdump
Eg:- --user option for tcpdump tcpdump -vv -nn -i eth0 host 10.200.2.1 and tcp dst port 8080 --user A Can someone tell me any tool which can do such thing? Even if it can show the process ID of the client application which is trying to establish network connectivity will do.
I just installed a fresh copy of debian (no GUI). I want all my traffic on bash (such as when I do ping or dig or wget, basically whatever) to be sent to localhost:8080. How can I do that? I've a ssh port forward setup that will forward all traffic arriving at my localhost:8080 to another server.
View 4 Replies View RelatedUnsure about IP tables lingo, so excuse me for not looking this up:I have a server, running IP tables, that I do not want to allow any type of outgoing traffic to 192.168.1.21
View 3 Replies View RelatedI'm running Linux Mint 10 . I have a wireless PCMCIA card (Linksys WPC 11 ver.3) that I've put into master mode, and I'm trying to set up my laptop as a wireless hotspot. I am very confident that I want to do this and have no interest in using a wireless router....I say that because that topic inevitably comes up with posts like this. The problem I'm having is I don't understand how to get wlan0 and eth0 to "talk" to each other...That is, I don't know how to set it up so that traffic from wlan0 goes through eth0, so that devices that connect to my hotspot can access the internet.I've seen a few guides about this, but they were either much broader in scope (i.e. much more complex), or for other distributions, etc, and it's too much for me to follow as a linux .
View 6 Replies View RelatedI am trying to set up a Linux box that can act as a router (and firewall later). I have a Debian 5 installation and it has two nics in it. I am trying to use the linux route command to set up a route between the two interfaces. I am finding it difficult to do. Let me explain how I am trying to set up my network: I have the ethernet cable from my modem connecting to eth0 of my Debian box, then I have eth1 connecting to a switch, which I connect all my computers and other devices to. I want to have two different ip address schemes for the devices. So here is my interfaces file:
Code:
#eth0 connects to modem
allow-hotplug eth0
iface eth0 inet static
[code]....
So I am wondering, to get my ethernet traffic from eth0 to eth1 and vice versa, do I need to make it so the Gateway for Destination 192.168.1.0 is 10.1.1.1, and for Destination 10.0.0.0, Gateway 192.168.1.0? I have looked at the linux manpage for route and I am still confused. I have also looked at the Debian networking page, but it is still unclear to me how to do this. how I am to use the route command to get this working? Or am I not even supposed to use the route command?
I've been trying to redirect all outgoing packets (destined for a specified ip address) from my slack box back to itself. I thought this could be done with iptables, but if I fire up wireshark I can clearly see that the packets are getting out to the real server and I'm getting responses from it.
So here's what I tried:
All looks good and fine, and then I even try to visit 194.28.157.42 with firefox (by the way I am running a webserver, that is set to show a page when you visit 127.0.0.1) and I get an error page that reads: 502 Bad Gateway.
I ignored this message to see what the program I'm trying to interrupt does, and when I start wireshark and then start the program that is using that website, I can clearly see that the packets make it to the real 194.28.157.42 and get back responses.
My linux machine is connected to the outside internet, and I have a minecraft server running on an internal machine (192.168.1.201). Right now, I am forwarding port 80 on the linux machine to 192.168.1.30, which is working.
iptables -t nat -I PREROUTING -i eth0 -d 192.168.1.30 -j DNAT --to-destination 192.168.1.201
iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
iptables -A PREROUTING -t nat -i eth0 -p tcp --dport 80 -m state --state NEW,ESTABLISHED,RELATED -j DNAT --to 192.168.1.201
______________________________
I want to filter out the GET/POST requests and forward them to port 8080. I can't seem to get that working.
I've tried this:
iptables -A INPUT -d 192.168.1.30 -p tcp --dport 80 -m string --algo bm --string 'GET' -j REDIRECT --to-ports 8080
I am using Debian 5 and I have some networking experience, however I want to learn to do this the best way possible. I have a Debian box with two nics and I want to connect that to a switch and use my Debian box as a router basically, as well as having a firewall setup within that too.
Should I use iptables to set up nat or the route command or what? I just want to know the group of tools to use in order to set up my network. Network diagram: Internet <------> Debian Box <----> switch <----> hosts I found some guides but they are for linux 2.4 and i'm not sure if they are right.
I have an Asterisk-server with 2 interfaces, a WAN-interface (eth1) and a LAN-interface (eth0).
SETUP : IAX-provider(internet) --> firewall --> Asterisk-server --> switch --> clients_on_LAN
So everything coming from the IAX-provider on port 4569 is forwarded to the Asterisk-server's WAN-interface (eth1). This needs then be routed to an internal SIP-phone (an IVR-system will define which one) via eth0. When a call is initiated from an internal SIP-phone (they register to the IP-address assigned to eth0) it needs to be routed via eth1 to the gateway (192.168.4.250). Asterisk will setup an IAX-channel on WAN-interface (eth1) to the IAX-provider (via gateway). So... will this work :
Code:
route add -net ip_IAXprovider netmask 255.255.255.0 gw 192.168.4.250 dev eth1
Code:
route add -net 192.168.4.0 netmask 255.255.255.0 dev eth0 (no gateway needed for the LAN-interface, communications to the gateway need to go via the WAN-interface !)
I'm using ubuntu server 10.04. I need to create a second network to do some testing. Here's what it looks like so far: WAN > x.x.x.x/9 > router > 192.168.1.0/24 > LAN
I need to do this: WAN > x.x.x.x/9 > router > 192.168.1.0/24 > LAN > ubuntu server (LAMP, dhcp, dns via eth1) [eth0 192.168.1.138] > ubuntu server [eth1 10.0.0.1] The two networks should be transparent to one another. I've got everything working, except routing. Here is ifconfig:
[Code]...
Im setting up a server thats connected to a large network. Now my external ip on the network is static and is 10.0.12.15. What I want is to create a dhcp network using the second port of my box. The first port eth0 goes to my network with the static ip 10.0.12.15 and my second port is connected to a switch with the static ip 192.168.12.1. Now dhcp works fine but none of the boxes that are connected to the internal ip cannot connect to the internet. Iv tried using squid and manual static ip routes. Im not using network manager or anything cause its a command line server.
View 1 Replies View RelatedI use linux.
I have below error, no route to host.