1
vote
0answers
9 views

How do I find which OS layer (iptables, rp_filter, etc) is dropping a packet?

Let's say that I'm running a ping towards a machine and I see from tcpdump that the icmp echo reply is being received at the ethernet port but the ping program is not getting it. So I know that ...
0
votes
0answers
7 views

network bridge not forwarding traffic from span port on router

I want to run several security network tools in LXC containers like ntopng, suricata, snort, etc. I hooked one of my server's NIC's up to a port that is spanned to my firewall... so basically this ...
0
votes
1answer
48 views

what could be blocking port 5060 on my ubuntu 14.04?

I have a ubuntu 14.10, and am trying to telnet into it via port 5060 but I keep failing. I always get the message "Connection closed by foreign host". I checked my iptable, it is default policy to ...
0
votes
0answers
52 views

captive portal and squid3 transparent mode

http://aryo.info/labs/captive-portal-using-php-and-iptables.html I did at practice. but squid (transparent mode should be) entered in the access.log s pages can not see. I use the following iptables ...
0
votes
0answers
25 views

ipset with iptables-persistent

iptables-persistent was not reloading my rules at restart, and I realized the problem was that /etc/iptables/rules.v4 contained a --match-set referring to a set of rules created by ipset - which had ...
1
vote
2answers
27 views

The program 'iptables' is currently not installed

I am a newbie, so my apologies up front. I am trying to get DansGuardian installed (which I believe I have) and working. To get it working I need to filter IP traffic through the app via iptables. ...
0
votes
1answer
40 views

Differences between UFW and GUFW

From what I have been able to piece together, the firewall that comes with Ubuntu is iptables, which is very complicated, so an easier way to access the firewall is through UFW and GUFW. UFW is ...
1
vote
0answers
70 views

Why aren't these ufw rules working?

I'm trying to configure ufw to only allow connections to 3 ip addresses on my local network, and deny everything else. Here's the commands I'm using: yes | sudo ufw reset sudo ufw default deny sudo ...
1
vote
1answer
123 views

What are the IP addresses in my iptables chain FORWARD settings in a Dokku/docker setup?

I've been playing around with Dokku on DigitalOcean (following this guide) and I'm trying to understand current firewall settings. So here's my setup: Ubuntu 14.04 Dokku Docker (as part of Dokku) ...
0
votes
0answers
172 views

Creating routes using iptables in ubuntu 14.04

I'm a newbie at ubuntu's administration although I've been using linux for a while just at user level. Let's show my problem. This is my network (only static IP addresses are used, for both private ...
0
votes
1answer
52 views

keep getting added to hosts.deny + iptables

I am confused to why this has started to happen. On my local network, if I click 10-20 apache/http links my server will decide to add me hosts.deny file and block me on iptables. Its not just ...
0
votes
1answer
296 views

How to open the ports on firewall in Ubuntu? [duplicate]

I'm pretty new to Ubuntu. I just want to open the most common ports namely FTP (port 20 TCP/UDP) HTTP (port 80 TCP/UDP) SMTP (port 25 TCP) ETC I've tried all the ways in iptables, ufw, and gufw. ...
0
votes
0answers
73 views

Unable to connect to Chromecast

I seem to be having a problem connecting to Chromecast from Ubuntu. Unlike the question How can I use Chromecast, the issue doesn't seem to be firewall related. I have already tried opening the ports ...
0
votes
0answers
69 views

iptables rules keep showing up

I just installed an ubuntu precise server, after a few weird communications issues I checked the iptables list and found: Chain INPUT (policy DROP) target prot opt source ...
2
votes
1answer
781 views

Iptables rules no longer honored

I installed Ubuntu Server 64-bit 14.04 a week ago. It worked fine for one to several days, then out of the blue, iptables became meaningless (I noticed FTP and such are down ). Only ports 22, 25 & ...
1
vote
2answers
89 views

What is MASQUERADE in the context of iptables?

In Iptables many times I see the target MASQUERADE. What is that. I searched and find lots of things. But I need some one explain me what MASQUERADE is in a so easy way? **If you bring an example ...
0
votes
0answers
51 views

Ubuntu 13.10 allows connections from LAN but not from outside LAN

SSH ports configured to all 22 and another one. I can connect from another Linux/Windows workstations on my home LAN no problem. Same thing for nomachines nx server. Teamviewer connects with no ...
1
vote
1answer
345 views

Firewall rules for transmission

I have transmission installed, which listens on the default port 51413. I have tried opening everything for this port. iptables: Chain INPUT (policy ACCEPT) target prot opt source ...
0
votes
1answer
42 views

iptables ruleset blocking all network activity?

I've gone through numerous trial and error to recently discover that my iptables result is the culprit of blocking all LAN and WAN activity. I know this, because if I comment out the last line in my ...
1
vote
0answers
101 views

Port forwarding out multiple VLAN interfaces that have same IP address

So I have an Ubuntu machine with multiple VLAN on an interface eth1 and each VLAN has the same IP address (172.16.0.2). I need to be able to simultaneously telnet into a rack of devices that are also ...
1
vote
2answers
5k views

ubuntu 14.04 default firewall rules

I would like to know exactly which scripts are responsible for default iptables rules (no ufw, no gufw) in Ubuntu Server 14.04. After fresh installation even with ufw disabled (by default) there are ...
0
votes
2answers
127 views

How do I with ufw deny all outgoing ports excepting the ones I need?

I did the following: ufw default deny outgoing, sudo ufw allow out 80 which I thought would let me use the Internet but didn't can y'all help? Also are there any other ports used by Ubuntu for which ...
0
votes
1answer
40 views

Ubuntu forward ports, default state, forwarding not working?

im running ubuntu 12.04.4 server. I been googling the nett for answers, but could not find any.. I would like accsess a few web-gui's on my server. I have forwarder the ports in my router, worked when ...
0
votes
1answer
213 views

Iptables and bind9 to forward to google's dns

Hello i have a very hard time on getting along with iptables and bind9 as my internal network dns server. It's configured to forward my queries to google's dns (8.8.8.8). The main problem is i can't ...
2
votes
1answer
69 views

Need help to make this file work in iptables

I came across the following example of how to use iptables to block internet access when the VPN connection is terminated abruptly: iptables -A INPUT -i lo -j ACCEPT iptables -A OUTPUT -o lo -j ...
0
votes
1answer
61 views

enable port 9696 on ubuntu server

I am using ubuntu server lts 12.04 on vmware virtual machine. I need to enable port 9696 which is blocked or filtered. When i use the nc -v -w 1 localhost -z 9696 command it shows me the following ...
0
votes
0answers
67 views

Port won't open! [duplicate]

I have a server that want to allow connections into it through port 25565, but when I test on http://www.yougetsignal.com/tools/open-ports/ it says they are closed? I have no outfacing interface ...
0
votes
0answers
80 views

how to set up iptables for dyndns server?

I have a server running with a dhcp public IP and ddclient updating my hostname from my public IP whenever it changes. My ISP has a feature for dyndns, so my router should automatically map my public ...
0
votes
0answers
75 views

Iptables help with server on 12.04?

I am trying to create a Minecraft server with port 25565 for me and my friends to access. I used to run one on my mac, where I would change the config for my firewall to allow connections through ...
0
votes
0answers
226 views

How to log firewall logs to a remote Syslog server

After much reading and unsucessful attempts, I do not manage to send some of my firewall logs to a remote server. Here is my setup: The remote server is a synology NAS, on which the syslog server ...
0
votes
2answers
87 views

Where did I fail with my basic iptables setup?

I installed iptables on a VPS (Virtual Private Server from openVZ) - Linux 2.6.32-24-pve #1 SMP Fri Sep 13 07:29:30 CEST 2013 i686 GNU/Linux. I also installed: apt-get install iptables-persistent ...
0
votes
1answer
137 views

UFW locks me out of server everytime I run it

Background: I'm setting up a new 12.04 instance on a VPS with a new provider.The VPS provider only offers a 32bit image but that really shouldn't matter here. I have no local access to the machine and ...
0
votes
0answers
171 views

Configure iptables for L2TP/IPSec VPN

I've been trying to get my server running a VPN so that I can connect to blocked sites in China while I'm traveling, but am having a few problems with iptables. My connection works fine if I flush my ...
2
votes
2answers
450 views

UFW not blocking connections to docker instance

I have a webservice running inside a docker instance which was run using the following command: sudo docker run -d -p 4040:4040 .... My UFW rules look like this: ~ sudo ufw status Status: active ...
0
votes
0answers
262 views

Minecraft Spigot Server BungeeCord and Iptables Help

I have had a BungeeCord server set up before and I know how it works. The problem I am having is with my iptables configuration. These are my iptables rules: #!/bin/sh #INPUT iptables -P INPUT DROP ...
2
votes
2answers
817 views

how do you create an app profile for ufw?

Ufw has a command that lists out profiles to which you can further explore their profile definitions $ ufw app list And $ ufw app PROFILE {app profile title} I was wondering how you can ...
3
votes
2answers
6k views

Help! My server has been hacked - .IptabLes and .IptabLex in /boot [closed]

I'm running a Ubuntu 6.06 dapper server and it has been hacked. I'll admit up front here that I'm a programmer and not a system administrator so even though I've worked with Unix/Linux for years my ...
1
vote
0answers
79 views

Allow users to access specified IPs only

I have a computer that offers both a VPN and a SSH server running three (separated) VPN networks. All users log into the server via ssh. However, I want that only certain users can communicate to ...
2
votes
2answers
257 views

UFW and firewall

So I recently installed ubuntu and I have been working with it no problem.While browsing through the security guides (specifically: https://wiki.ubuntu.com/BasicSecurity) I noticed this: "enable the ...
0
votes
1answer
200 views

OpenBSD Packet Filter firewall in Ubuntu

Is there a way to use OpenBSD's Packet Filter firewall in Ubuntu?
2
votes
1answer
482 views

I can not connect on ubutu service port 3050, from my network

I have the Firebird service running on my ubuntu server and it is working fine inside the server. But when I try to use from another machine it does not work. Like a firewall issue. I did make some ...
0
votes
1answer
110 views

Ubuntu VPS > restrict openerp for some user

In Ubuntu VPS server, openerp is running and anyone can using this web interface. my vps server is: http:// <Public IP>:8069/. I want to allow some mac addresses and restrict to all. Here is ...
0
votes
0answers
130 views

how to proxy to a VPN connected server with local services running?

I'm having trouble accessing services that are running on my Linux Box from outside the local network. The setup is not as simple as most tutorials describe so I'm a bit stuck. My Linux Box (running ...
0
votes
0answers
52 views

UFW problem : can not access certain pages

Hello, I configured iptables using ufw to deny traffic from and to anywhere except my chosen ports. This is my /lib/ufw/user.rules : *filter :ufw-user-input - [0:0] :ufw-user-output - [0:0] ...
0
votes
1answer
43 views

Trouble saving iptables

I am having some issues with removing an iptable entry I have entered. I added -A PREROUTING -d 95.211.213.149/32 -i venet0 -p tcp -m tcp --dport 443 -j REDIRECT --to-ports 1194 To experiment ...
2
votes
1answer
8k views

Where are iptables's rulesets stored on Ubuntu 12.04?

Ubuntu 12.04 LTS - iptables v1.4.12 TLDR: Where are iptables's rulesets saved when invoking iptables-save <ruleset-name> ? Explanation: According to this answer basic way of saving ...
0
votes
0answers
238 views

Foraward Traffic from local machine to proxy server using iptables

I am using Ubuntu Server 12.04. My IP is 192.168.4.160. I want to route the HTTP traffic generated locally from my system destined to a particular URL (say x.x.x.x) to pass through proxy server. My ...
0
votes
1answer
920 views

Can't delete an iptables chain

I'm having a problem on deleting a user-defined chain. these the are rules I entered. sudo iptables -t mangle -N internet sudo iptables -t mangle -A PREROUTING -i eth1 -p tcp -m tcp --dport 80 -j ...
0
votes
1answer
61 views

after software update, website not accessible

I just applied a bunch of recommended updates this morning (which seems to have upgraded the kernel to 3.8.0-32.47), and suddenly I cannot connect to the machine on port 80 (http) or 22 (ssh). Ping ...
1
vote
0answers
2k views

Ubuntu 12.04 LTS - vsftpd problem. No connection. Connection refused

i have a problem with vsftpd server running on Ubuntu 12.04 LTS. Here is the configuration: ubuntu Server address - 192.168.5.100 router address - 192.168.5.1 roger/# grep -v "#" /etc/vsftpd.conf ...