2022 Developer Survey is open! Take survey.

Questions tagged [iptables]

Iptables is used to set up, maintain, and inspect the tables of IP packet filter rules in the Linux kernel.

Filter by
Sorted by
Tagged with
0 votes
0 answers
19 views

system ip still getting detected after using iptables and redsocks

Here is my redsocks.conf base { log_debug = off; log_info = on; log = "syslog:daemon"; daemon = on; user = redsocks; group = redsocks; redirector = iptables; ...
user avatar
0 votes
0 answers
10 views

ufw default deny routed not working

I am setting up ufw default deny routed and it is not reflecting in iptables -L How to ensure it is disabled what I tried: root@VM01:~# ufw default deny routed Default routed policy changed to 'deny' ...
user avatar
  • 101
0 votes
0 answers
22 views

Allowing port 80 and 53 from one network to another

I have two local networks(intnetA and intnetB). intnetA has one computer with windows 7(IP: 192.168.90.1) intnetB has two computers, one windows server 2012(IP: 192.168.91.1) and one windows 7(IP: 192....
user avatar
0 votes
0 answers
33 views

What does rule section ufw-not-local do?

While using ufw for my Ubuntu 22.04, I try to understand the iptables structure behind it. What concerns me specifically is this snippet taken out of /etc/ufw/before.rules: # # ufw-not-local # -A ufw-...
user avatar
  • 1
0 votes
0 answers
9 views

OpenVPN blocks outgoing Apache sites

I host a site to teach SQL (databases.pacha.dev) by using Apache in a DigitalOcean droplet. I wanted to install OpenVPN to have a VPN in the same server, and I run this as root #!/bin/bash echo "...
user avatar
0 votes
1 answer
26 views

What happens with empty iptables?

From that answer, and other comments on the same webpage, I came to the conclusion that ubuntu by default has an empty iptables. However, people said it was safe, because unless the unexperimented ...
user avatar
0 votes
0 answers
26 views

Hotspot only works after starting and stopping already disabled ufw service

I have recently decided to try out firewalld instead of ufw. After installation I ran these two commands to theoretically make the switch sudo systemctl disable ufw and sudo systemctl enable firewalld....
user avatar
0 votes
0 answers
20 views

OenVPN connection failed, port is not opening with ufw (code=111)

Im trying to set up an openvpn on my pc (which is running Ubuntu Server 22.04). I've used the quick install script listed here When i try to connect on my linux machine i get the following error: 2022-...
user avatar
0 votes
1 answer
22 views

Ubuntu Server 20.04 random ports are timing out, and I don't know why

I need to access a webserver on my Ubuntu Server 20.04 installation. For a test, I set up a webserver using sudo python3 -m http.server <port>. It works fine for a bunch of ports, like 8000, 443,...
user avatar
0 votes
0 answers
38 views

Abrir puertos en Ubuntu server 22.04 [closed]

Hola comunidad me gustaria saber como puedo abrir el puerto 25 y 2396 de mi servidor ubuntu, ya que abro el puerto por ufw, firewalld, iptables y al realizar las verificaciones en https://ping.eu me ...
user avatar
0 votes
0 answers
24 views

20.04 - Can't persist IPTABLES rules

I need to share my wireless modem with another laptop via ethernet. It works perfectly with: iptables -t nat -A POSTROUTING -o wwan0 -j MASQUERADE iptables -I FORWARD -o wwan0 -s 192.168.9.0/24 -j ...
user avatar
0 votes
0 answers
18 views

ubuntu iptables port accesses

Is there a setting to turn off/on country access to certain ports in Ubuntu? For example, I don't want port 1111 to be logged in Germany. Is there an iptables command for this?
user avatar
  • 1
1 vote
0 answers
91 views

Open server port 80 and redirect to container IP

I'm not an heavy user of unix based systems. And I have some trouble opening a server's port (80) to the public and redirect it to a running container. So basically, I have a running container on a ...
user avatar
  • 61
0 votes
0 answers
20 views

iptables.service active on startup

I've apt installed iptables-persistent and my tables boot on startup as intended. However, the service that is loaded on start up is netfilter-persistent. My compliance script requires the actual ...
user avatar
  • 13
0 votes
0 answers
25 views

Permissions issues after upgrade

I noticed this morning after I ran an apt-get upgrade && apt-get update and rebooted that I'm unable to docker build an image that I was able to build before I restarted. I tried to ping from ...
user avatar
  • 139
0 votes
0 answers
53 views

Ubuntu 20.04 ssh possible but NO Access on custom port

Fresh install of 20.04 LTS on Small Form Factor Intel user@host:~$ cat /proc/cpuinfo processor : 0 vendor_id : GenuineIntel cpu family : 6 model : 76 model name : Intel(R) Pentium(R) CPU ...
user avatar
0 votes
1 answer
28 views

how to get all rules for a specific IPaddress

Is there any known way how to get all iptables rules ipsets and so on which are valid for an specific IPaddress so that I can see missing ones with a simple view ?
user avatar
  • 1
0 votes
1 answer
47 views

Incoming connections getting blocked on some ports with no firewall rules Ubuntu server

I'm a relatively inexperienced Linux user and I'm having issues with connections to my machine. I'm using Ubuntu Server 20.04 LTS I have a web server, a samba server, a game server and a ssh server ...
user avatar
  • 1
0 votes
0 answers
11 views

Reaching ubuntu 18 hostspot internal network

I am a newbie to netwotrking and would appreciate some help on a networking issue. I have a ubuntu laptop connected to internet router. I have created a hotspot in the same laptop and connected ...
user avatar
1 vote
2 answers
169 views

How to open port to outside world?

I have a remote server with an IP - 111.222.333.444 I want to run an http server on that machine, that runs on localhost:8000 How can I make requests to 111.222.333.444:6000 from outside, from my hope ...
user avatar
  • 11
0 votes
0 answers
68 views

Docker daemon fail to run 'MASQUERADE': No such file or directory

I have some issue to install and run the docker daemon on Ubuntu 21.04. During the install of the packages I am getting this bit of fail message : Job for docker.service failed because the control ...
user avatar
0 votes
1 answer
66 views

iptables - use ubuntu as router

I have an ubuntu PC which I would like to use as "general server" (I don't know a good name for the purpose, let me try to explain). I have several other devices in my network, bunch of ...
user avatar
  • 125
0 votes
1 answer
26 views

Whitelisting friends' dynamic IPs w/o much extra effort from them

I'm running a small https webserver using a Javascript-based program that I've heard isn't super secure. Fortunately, I only want a couple of friends to be able to access it - unfortunately they're ...
user avatar
0 votes
1 answer
23 views

iptables Explicit Allow Policy

I am attempting to setup an Explicit Allow policy on my 20.04 Ubuntu web server. By running the following: iptables -P INPUT DROP Also added rules for ssh, http and https. Resulting in the following ...
user avatar
  • 103
0 votes
1 answer
77 views

How to allow a port to accept connection from all external ip adresses?

I have just started using Linux. My OS details are following. Distributor ID: Ubuntu Description: Ubuntu 18.04.3 LTS Release: 18.04 Codename: bionic I want to accept TCP connections ...
user avatar
0 votes
0 answers
80 views

UFW not blocking IP address

I am trying to block an IP address from my server. ###ufw status verbose Status: active Logging: on (low) Default: deny (incoming), allow (outgoing), disabled (routed) New profiles: skip To ...
user avatar
1 vote
1 answer
48 views

How to prevent flood of unwanted established connections - iptables

There seem to be a flood of unwanted, established port 22 connections to my server. When running sudo netstat -natup | grep 'ESTABLISHED' as root, I get a long list of unwanted established connections,...
user avatar
  • 31
0 votes
1 answer
62 views

Can not connect Ubuntu Server ssh from outside

We have ubuntu server installed on our desktop machine. It is connected modem with ethernet port. We can access it with ssh via inside of our network. But can not from outside. Here is what we've done ...
user avatar
  • 1
0 votes
0 answers
142 views

MySQL remote connection timeout and port 3306 close

I've been searching through the whole a fix but nothing worked. I'm trying to allow remote access to my MySQL db. I've been editing my /etc/mysql/mysql.conf.d/mysqld.cnf to modify bind address to set ...
user avatar
1 vote
0 answers
88 views

How do I use UFW to block a device in Ubuntu hotspot?

I have a laptop running Ubuntu 20.04, which connected to the internet via ethernet. I have setup a WiFi hotspot on this machine, so that I can share its internet connection. Say, I have third device (...
user avatar
  • 11
0 votes
0 answers
43 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 ...
user avatar
0 votes
0 answers
45 views

How to test if firewall is working/troubleshoot it?

So I recently moved my media server to a new computer and moved from popOS to Ubuntu 21.10. I have NPM set up on docker as a reverse proxy and have port 80 and 443 forwarded on the router to my server....
user avatar
0 votes
0 answers
24 views

Iptables gateway slow

I am trying to use an old laptop as a gateway from wired lan to a wifi internet hotspot: lan router->ubuntu laptop->internet hotspot I found a recipe to set up the laptop as a gateway, which &...
user avatar
0 votes
0 answers
20 views

Port forwarded on router, Port Open on PC, Port setup with python server to listen. Port check tools still say it's closed

UFW is disabled, I used iptables to open the port. If I do netstat -tulpn then it says the port is in a listen state. On the router I have the port forwarded to the linux machine. I figured maybe it ...
user avatar
  • 1
0 votes
0 answers
28 views

iptable rules to allow downloading stuff while default policy is on DROP

I was trying to install bind and for some reason I was getting issues most likely due to my iptable rules , I can ping google.ca anybody have any reccomndations down below are my current rulesets ...
user avatar
  • 1
0 votes
1 answer
29 views

I am creating a home lab using VMs and routing internet but I cant resolve names?

I have my first vm1 routing internet using iptables -A POSTROUTING -J MASQUERADE to second vm and vice versa on second VM my third VM can ping 1.1.1.1 (internet) and I set it a public DNS like 1.1.1....
user avatar
  • 1
0 votes
0 answers
26 views

Wireguard Ubuntu Server Virtualmin FirewallD Connectivity

Does anyone know of any Ubunut Server 20.04 and/or Virtualmin related aspects that can interfere / block a wireguard connection? Problem: All settings verified as correct. Client just can not connect....
user avatar
0 votes
0 answers
59 views

I wanted to allow outgoing DNS traffic while OUTPUT is on DROP

I currently have a dns server running on my pi , and I am using that as my dns I wanted to ping google.ca while my output chain / input being on drop here are my firewall rules would love to hear some ...
user avatar
  • 1
-1 votes
1 answer
28 views

How to redirection traffic between interfaces on ubuntu 18.04

i have server that has two interfaces (enp1s0 : 192.168.1.10 and enp2s0 : 10.20.30.30), enp1s0 is public interface that we can connect to server with it and enp2s0 is private and isolate interface. on ...
user avatar
1 vote
1 answer
109 views

netfilter-persistent seems ok but does not load rules after reboot

Other people have similar issues but I tried all their approaches with missing iptable entries on boot, no success so far :| (it appears not to be a typo in the iptable files during load) I've added a ...
user avatar
  • 113
0 votes
0 answers
99 views

Allow incoming traffic from ipv6 address

So here´s my problem. I changed the internet provider recently. Now I have an ipv6 address only. On my linux server, I used a bash script, to update the iptables rules due to my ipv4 address changing ...
user avatar
0 votes
0 answers
36 views

Port 80 showing as filtered, ufw inactive

sudo nmap -sS 3.139.146.153 PORT STATE SERVICE 22/tcp open ssh 25/tcp filtered smtp 80/tcp filtered http 443/tcp open https 3306/tcp open mysql 7000/tcp open afs3-...
user avatar
0 votes
0 answers
31 views

Monitor Openvpn log and if it get specific alert.......then execute iptable command to ban IP

I am looking to secure my openvpn server and to automatically ban unauthorized login attempts. I am looking for a script that will do the following: -Monitor /var/log/openvpnas.log -Look for the ...
user avatar
  • 1
0 votes
0 answers
92 views

Why do I have dropped incoming packets from various IPs?

I have an Ubuntu VM serving as a WireGuard peer. My network only has my WireGuard port forwarded to my VM (51820 to 192.168.1.2). I think my iptables (below) are set up to only allow (1) SSH from my ...
user avatar
  • 101
0 votes
0 answers
21 views

share internet , connecting to vpn

I installed a vpn import the vpn settings (protonvpn) through the ubuntu vpn panel I configured username and password. vpn works normally on ubuntu machine. which works as a gateway to another machine ...
user avatar
0 votes
0 answers
39 views

iptables on Ubuntu-server with Wireguard client

I have an older "HP Optiplex 3020" with 8GB memory that I use as an "Internet router". I have installed Ubuntu Server 20.04.3 and with Webmin DHCP-server DNS-server Postfix ...
user avatar
0 votes
1 answer
45 views

how to get internet while your default policy is DROP in iptables [closed]

how to get internet while your default policy is DROP in iptables basically I want to block all unauthorized traffic with iptables I set my default policy to drop (INPUT) and that caused me to not ...
user avatar
  • 1
0 votes
0 answers
37 views

IPtables firewall rules - Ubuntu

Can you please explain to me the difference between this 2 IPtables rules, there were implemented to transfer packets from external internet users to a local server : iptables -t nat -A PREROUTING -p ...
user avatar
0 votes
0 answers
49 views

ip6tables ipset --set-mark

ipset create mylist4 hash:net family inet ipset add mylist4 8.8.4.0/24 ipset add mylist4 8.8.8.0/24 ipset create mylist6 hash:net family inet6 ipset add mylist6 2001:4860::/32 ipset add mylist6 2401:...
user avatar
0 votes
1 answer
295 views

Yet another SSH connection timeout [closed]

This one is puzzling me to no end. By using PuTTY (latest version) I was able to connect from Windows 10 to Ubuntu 18.04 via SSH (local network), and I've been doing it for over a year until it ...
user avatar
  • 1

1
2 3 4 5
25