Tagged Questions
0
votes
0answers
10 views
Route dns+dhcp requests through iptables?
I have a Raspberry Pi which I'm attempting to use as a range extender for my home wifi network. I've installed and setup hostapd with the same settings as my router, so that any devices will select ...
0
votes
0answers
8 views
Prevent device from reaching WAN traffic (MAC address for example) - OpenWRT
I want to forbid a device on my network from accessing the internet.
Computers still have to communicate with the device, and vice versa.
OpenWRT version: OpenWrt Attitude Adjustment 12.09
0
votes
0answers
28 views
Redirect traffic from 80 to 8080 using iptables
I have two interfaces eth0 and eth1. Traffic is copied (reflected) from another machine to my eth0 so that I can analyse it. On eth1, my analysing software listening port 8080 is installed. I want to ...
0
votes
0answers
23 views
Iptables: Filter broadcasted UDP packets on specific interface
My PC has two network interfaces (eth0 & usb0) that are bridged. There is a service on my PC that broadcasts UDP packets on a specific port (7000). I would like to prevent these UDP packets from ...
1
vote
0answers
20 views
Change UDP port with iptables for VPN clients
What I want to do is say that for all UDP connections on interface ppp0 that have a destination port of 53, change that destination port to 1053.
I am attempting to change the destination port of UDP ...
2
votes
2answers
169 views
No idea what is listening on port 80 in OS X
I'm on OSX Mountain Lion 10.8.3, and I've freshly rebooted my Mac.
I want to start a service (like Apache on port 80), but there is already something going on with port 80:
telnet localhost 80
...
0
votes
1answer
18 views
Linux gateway / DNAT: restrict to certain interfaces
I have various machines with a number of network interfaces:
eth0: a local LAN
eth1: sometimes used for the connection to the Internet gateway
ppp0: Modem uplink as an alternative to eth1
tun0: ...
0
votes
0answers
17 views
Forwarding traffic using nc on a linux box
On my system, I am sharing my internet which is on eth0 (ethernet) through wlan0 (wifi card).
I am then using mitmproxy to monitor the traffic and look into the ssl packets.
However, mitmproxy only ...
1
vote
1answer
165 views
Limit UDP outbound traffic to loopback (localhost) instead of eth0
Atm i'm testing it on Ubuntu Server at VMware Workstation + Windows 7 local host with bridged connection. Later this has to go to live server.
I have VLC streaming video file on Ubuntu with
cvlc ...
0
votes
2answers
23 views
Problems in creating rules in iptable
Hello to all :) I need a little help with creating a rules. Im starting to learn iptables and firewalls but I have some questions. I need to allow HTTP communication only from PcA to PcB./
My code is:
...
0
votes
0answers
53 views
iptables rule for loopback interface lo
I want to test some network performance, where I need to use a tcp client to connect to a tcp server program on the same host, so I used localhost(127.0.0.1)
however, when the TCP SYN is sent, it get ...
0
votes
0answers
232 views
How does iptables masquerading allow to access a different local subnet?
My Linksys router (IP 192.168.1.1 inside a /24 subnet) is connected to my ADSL modem (IP 10.0.0.138 inside a /24 subnet) to establish an internet connection via PPPoE. To be able to access the modem's ...
1
vote
2answers
269 views
linux routing outbound port 80 traffic via ssh tunnel, iptables, or a simple route
I have two hosts, A and B. Host A hosts services on port 8080 and has outbound internet firewall rules allowing port 80 and 443 access to Host C.
Host B is on the same subnet as Host A. Host B is ...
0
votes
1answer
65 views
using iptables to prevent RST related to a specific port
I have a program which uses libpcap to capture incoming TCP SYN packets, these SYN packets are destined for a specific port.
But I have no tcp listening socket for that port, so in practice, the OS ...
0
votes
3answers
62 views
iptables rules are not in action
I have a iptable rule file, on the INPUT chain I have
-A INPUT -i em1 -p tcp -m tcp --dport 54000 -j ACCEPT
-A INPUT -i em1 -p tcp -m tcp --dport 30000 -j ACCEPT
-A INPUT -i em1 -p udp -m udp --dport ...
1
vote
2answers
395 views
IPtables Rules to Block IP Range
I've applied the following rules from a text file called "iptables.save" to iptables.
But to my dismay, I found that the ip address 107.22.26.176 is still able to access my server via TCP.
What did ...
0
votes
2answers
88 views
Iptables: Allow Internal LAN to access INTERNET
I have an internal network behind my router on eth0, and I have my router connected to the internet thorugh wlan0. I can't access the internet from inside the lan, how can I fix this?
wlan0: ...
0
votes
1answer
84 views
UDP packet and firewall
I notice when I send udp packets from computer A to computer B,
B can receive the upd packets correctly
but if I send udp packets from computer B to computer A
the udp packets are not received
A and ...
0
votes
1answer
119 views
unable to connect to localhost:80 after installing nginx
I just installed nginx by doing sudo yum install nginx and I'm unable to connect to it on port 80.
I tried stopping iptables by doing sudo service iptables start and was still unable to connect.
I'm ...
1
vote
1answer
48 views
iptables simple forwarding setup woes
I have iptables running on a host (acting as a firewall) in a Linux namespace with only one network interface: h2-eth1 (has an IP and MAC address)
I have set up my switch to forward all packets to ...
1
vote
1answer
82 views
Port-Forwarding for Click'n'Load remote usage
I've got JDownloader running on my HTPC and access it via VNC.
The problem with Click'n'Load (CNL) is, JD only listens on localhost:9666 for incoming traffic, and the browser applications only send ...
3
votes
1answer
310 views
IP forwarding on the same network
I have a raspberry pi that I have put wifi on. I am also using its ethernet connection to bring internet to my XBox 360. I want to bridge these connections AND keep them both on the same network.
For ...
1
vote
0answers
443 views
How do I configure DD-WRT to forward IPSec traffic to an internal server to support a road warrior configuration?
I use dd-wrt as my home router setup and that's been working fine. Now I wanted to figure out a way to be able to use my iPad to set up a IPSec tunnel to my home network while I'm on the road.
PPTP ...
2
votes
2answers
533 views
Using iptables SNAT based on source interface and ip address
I would like to change source ip address according to ip address and interface it came in. Let's consider following example:
-----------------------------
| |
| ...
1
vote
0answers
340 views
iptables routing marked packets from router to PC and routing them back to router
I'm trying to do deep packet inspection on HTTP packets. The purpose of this is to collect HTTP payload data and then create some proxy/cache-independent reports. Following this, the idea is to ...
3
votes
1answer
330 views
Access Apache server running in Fedora guest VirtualBox from host
I have trouble accessing Apache server from host.
I’ve Fedora 15 VM VirtualBox installed on Windows 7. Within this VM I have Apache server running and working fine within the guest.
Not sure what ...
1
vote
2answers
139 views
How to “shut off” all networking on Linux from bash?
I'd like to write a bash/shell script that "turns off" the machine's ability to communicate over it's network card, effectively shutting down all networking. From the command line:
# To turn all ...
1
vote
2answers
314 views
iptables port based routing
I've been Googling this for days with no success. I connect to a VPN from my server from time to time and I'm trying to configure my Debian server to only use port 80 and 443 through the VPN and all ...
0
votes
1answer
58 views
How to resolve conflict in iptable rules
In Ubuntu 12.04 and above there are no iptable rules defined by default. I added the following rule and it works fine:(Update)
iptables -A INPUT -p tcp -j QUEUE -m string --string xyz --algo bm
...
0
votes
2answers
294 views
How to route the incoming connections through a specific interface?
I have multiple ethernet cards with two different set of networks configured on them.
The output of route -n is given here::
Kernel IP routing table
Destination Gateway Genmask ...
3
votes
1answer
864 views
Load balancing with multiple gateways
I have to different ISPs, each on each own network. The main connects via ethernet and the secondary via wifi. The two networks have no relation at all. I just connect to them simultaneously. The ...
0
votes
2answers
621 views
need to route the traffic through a specific network card
I have two network cards and they both have a different network. I need the outgoing connections to go only through a specific network card. Any help ?
Update:
I ran a route -n command and got this ...
1
vote
1answer
144 views
dd-wrt: Keep source ip after port forward
I just started using dd-wrt on my wndr3700, but now all my incomming connections to a server inside the network gets the same source ip as the router. How can I change this back so I get the real ...
0
votes
1answer
433 views
Will increasing number of rules in iptables slow down my internet
How much impact will the rules have on speed, if we are using match to queue the packets.
1
vote
1answer
229 views
internet connection gone after $ iptables -F INPUT
I have a PC with two Ethernet cards, and I was trying to configure my eth1, but when I typed $ iptables -F INPUT, the internet was gone on eth0. Does anyone has any idea how to get my internet ...
2
votes
1answer
451 views
How to match multiple strings in iptables
I have 2 strings, and i wish to queue the packet if it contains both the strings ( something like ("jsh"&&"gjhyg")), i tried following ways, but they don't seem to work:
sudo iptables -A ...
1
vote
0answers
74 views
How to redirect local connection to my things in IPv6 on linux?
With IPv4 I can make some program connect to my service instead of where it wants using REDIRECT and DNAT targets in OUTPUT chain in iptables (sometimes combined with -m owner)
In IPv6 hovewer I ...
0
votes
1answer
112 views
Is it possible to figure out which http request generated the corresponding response
I am using iptables to listen to tcp (http) packets. I am filtering out INPUT responses containing a matching string. Is it possible to know which http request generated the response. Assuming 10 ...
1
vote
1answer
79 views
Separating two networks
I have two routers, R1 and R2.
R1 (a stock linksys router running dd-wrt) is connected to internet and is serving internet to a network of 5 devices/PCs running a DHCP server, with a network of ...
1
vote
1answer
644 views
Gateway on a virtual network interface used by LXC guests
I'm currently having some problems with configuring a gateway for a virtual network interface.
Here is what I've done :
I created a virtual network interface :
# brctl addbr lxc0
# brctl setfd lxc0 ...
3
votes
1answer
85 views
Use port forwarding with masquerade
I'm using a debian as a router with nat configured. How can I set up port forwarding, to set an rdp server on the local network for example?
2
votes
2answers
453 views
Iptables port mapping from two PCs to one
We have 3 PCs, two of it are connected to internet (both of it have 2 NIC)
PC1:
eth0 - 1.0.0.1 (external IP)
eth1 - 172.16.0.1 (internal IP)
PC2:
eth0 - 1.0.0.2 (external IP)
eth1 - 172.16.0.2 ...
0
votes
1answer
84 views
NATing with a single-homed machine possible?
I have the following setup:
a) a single-homed machine, A, that can see the Internet.
b) other machines B, C, and D that cannot see the Internet.
c) A, B, C, and D can see each other.
d) all ...
0
votes
1answer
193 views
How to setup IPtables to allow capture network traffic from a virtualbox VM configured with NAT
I would like to have a VirtualBox virtual machine that can't get online. I want to be able to monitor all network traffic attempts from the Linux host.
So, if the virtual machine attempts to make a ...
1
vote
1answer
293 views
linux drops packet when trying to route it - why?
I track packets using LOG targets for all chains of all tables and the last chain I see my packet in is the POSTROUTING chain of the mangle table:
mangle_PREROUTING: IN=eth0 OUT= ...
4
votes
1answer
842 views
iptables vs route
What's the difference between these two tools?
Can anybody tell me what the main workflow of networking behind Linux (in relation to IPv4 packet filtering, NAT and IP routing table) is?
0
votes
1answer
93 views
Mark packets across computers?
I use Transmission on Ubuntu and I'm having this issue, which basically says that QoS is broken because there is no way to limit which outgoing ports uses.
I was thinking of doing a dirty and ugly ...
0
votes
1answer
481 views
Linux, how to force all traffic to specific host over VPN?
I'm trying to ensure that all traffic to our stats server is forced over the VPN, in the case that the VPN falls down, it shouldn't be that the traffic tries to route over the WAN. To short-circuit ...
2
votes
1answer
143 views
Secondary NIC: what all can I do?
I was loaned a NIC which I promptly installed in my F16 workstation just to 'play' with it (using iptables and stuff).
Other than forwarding packets from the new NIC to the old NIC using various ...
0
votes
1answer
811 views
will the left|rightfirewall option of StrongSwan open UDP 500/4500 and protocol number 50 on iptable?
I know the StrongSwan use UDP 500 and 4500 for IKE traffic and IP protocal number 50 for ESP packages.
I am not sure the usage of left|rightfirewall ...
