All Questions
27
questions
-2
votes
0
answers
35
views
Modules disappear after reboot
Dear friends something really strange is happening in my system. The ip_tables module did not seem to be installed so I proceeded to reinstall the kernel and all modules:
sudo apt-get install linux-...
- 97
2
votes
1
answer
293
views
How to tunnel all the traffic for one interface through another interface
I have two working interfaces on my ubuntu machine:
tun0 - OpenVPN server with the internal address of: 10.8.0.0/24
wg0 - WireGuard peer interface with the internal address of: 10.7.0.0/24 which is ...
- 21
0
votes
1
answer
1k
views
Cannot connect to home ubuntu server using public static IP address outside of LAN
Running ubuntu 22.04
I have a test express.js app running and I can connect to it via 192.168.1.6:3000 as local ip and also as (static public IP):3000 but only from devices connected to my WiFi.
As ...
- 17
0
votes
0
answers
979
views
Not able to load iptables
I am trying install iptables for UFW but having issues with it.
Here is how I am installing iptables:
agganu@agganuserver:~$ sudo apt-get install iptables
Reading package lists... Done
Building ...
- 1
0
votes
1
answer
107
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 ...
- 103
1
vote
1
answer
333
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,...
- 31
2
votes
1
answer
3k
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 ...
- 123
1
vote
1
answer
1k
views
Prevent routing of DHCP traffic
First, I'm aware that similar questions to mine have been asked elsewhere (I've read many of those posts!) but I've not been able to figure out a solution to my problem, so I'm asking for help.
My ...
- 11
2
votes
1
answer
5k
views
probleme running ufw on Ubuntu 20.04.3
I'm new to Ubuntu and to try it out I've installed the Ubuntu app from Microsoft store and running it on my windows 10 laptop, I tried to enable the UFW but I got this:
:~$ sudo ufw enable
ERROR: ...
1
vote
0
answers
17
views
Failed to apply network settings - file /sbin/iptables doesn't exist for bluetooth xubuntu 20.04 [duplicate]
After upgrading xubuntu 16.04 to 20.04, when I reboot I always have this popup :
bluetooth works : I can send and receive files.
I've tried to reinstall iptables but nothing changed.
Thanks very much ...
- 53
1
vote
1
answer
949
views
Create network alias in Ubuntu 20.04
I have a local application that will try to connect to MySQL on 172.1.0.1 when it's on production but I want to be able to test it locally.
At this time, changing the source code is not an option, so ...
1
vote
1
answer
6k
views
does adding a rule to iptables mean it takes effect immediately?
I run sudo iptables -A INPUT -p tcp -m tcp --dport 2222 -j ACCEPT in bash and then tried to connect to that machine via another machine on the same LAN / subnet via port 2222 with PuTTY and it didn't ...
- 221
0
votes
1
answer
369
views
My Firewall script is blocking nginx Rtmp Client connection
My server is running Nginx Rtmp Server on Port 1935
I am running a firewall script to block bad clients who connect on my server over 30 times on any tcp Port
with the following script
#!/bin/sh
# ...
- 35
1
vote
1
answer
4k
views
Unable to add rules to /etc/ufw/before.rules and before6.rules
I run a high-traffic NTP server and the following rules are absolutely necessary to prevent my conntrack table from being immediately overrun (regardless of how large it is):
iptables -t raw -A ...
- 301
0
votes
1
answer
4k
views
Bad argument in iptables NAT command
I am trying to do a DNAT rule in iptables if the packet with source address 192.168.86.212 and destination address 192.168.86.212 then change the destination address to 172.217.5.100.
sudo iptables -t ...
- 137
1
vote
1
answer
257
views
Isolate hosts on Netplan defined Bridged network
I've Ubuntu 20.04 LTS for Raspberry PI and I've created a wireless access point using the snapon wifi-ap package. That allows hosts to attach to a 192.168.8 network and works beautifully the Ubuntu ...
- 1,405
0
votes
1
answer
2k
views
How to set up iptables to access my apache2 server from public IP
I've got my Oracle Cloud instance on ubuntu 20.04 and I set up apache2 server. It's working from curl localhost but It doesn't work from my instance public IP. My ufw status:
Status: active
To ...
user1150482
0
votes
1
answer
798
views
I have to type in port 80 after my website to see it (www.example.com:80 - but only with ssl)
I am new to server management and decided to learn by deploying my own website :D
The problem is probably that I misconfigured iptables / didn't configure them enough.
I have a node app running on ...
- 115
3
votes
2
answers
2k
views
Update from 20.04 to 20.10 - iptables not replaced with nftables
According to this article on itsfoss.com nftables should replace iptables after updating from 20.04 to 20.10.
In my case not only is iptables still installed, but also nftables is missing.
Does it ...
11
votes
1
answer
12k
views
Why is my port closed when accessing from the network?
I have read so many pages, and tried so many things, but am stuck here.
I have a freshly installed Ubuntu 20.04 server. And on it I run a Django test server (just to try it out). It is running and ...
- 304
0
votes
1
answer
373
views
ufw iptables-nat module not found after update to linux-images-5.8.0-12-generic Ubuntu 20.04
Anyones got a problem with iptables with the new kernel update ?
I try to do a modprobe iptables-nat but it's like the modules is not part of the new kernel.
When I choose kernel 5.4.0-42 in grub it ...
- 3
1
vote
1
answer
166
views
Why is wlo1 not routing DNS response back to enp4s0?
I'm sharing my wifi connection (wlo1) via ethernet (enp4s0) to another device. The packet forwarding worked until the host device rebooted.
All routes and IP addresses are static, set up using NMCLI.
...
- 336
1
vote
1
answer
959
views
On new linux kernel 5.8rc7 in Ubuntu 20 docker will not start
I have installed the new Linux kernel 5.8rc (not stable) using the mainline installer. Almost everything I tested worked fine except for Docker which would not start. Looking at the logs the issue ...
- 147
9
votes
3
answers
45k
views
Ubuntu 20.04 can't persist the Iptables configuration
I have been doing this in all previous Ubuntu editions without an issue, but something has changed in Ubuntu 20.04.
sudo apt install iptables-persistent
iptables -A INPUT -p tcp -m tcp --dport 443 -j ...
- 975
4
votes
1
answer
2k
views
How do I configure sshguard in Ubuntu 20.04?
I have previously used sshguard successfully on Ubuntu 16.04 by simply installing the sshguard package. When I tried to do the same on 20.04, however, I discovered that it was only mostly working: ...
- 220
1
vote
2
answers
2k
views
Cannot use apt/curl/wget/git but can Ping
I have a raspberry pi running ubuntu server 20 and cannot connect to the internet, but can use ping. This question has been asked by many before, however the solutions provided in those questions do ...
- 31
3
votes
1
answer
4k
views
Ubuntu 20.04 Focal, Network Manager Hotspot, 'No Internet connection'
After upgrade Ubuntu 18.04 to 20.04, I noticed Hotspot feature seemed working, and phones were able to connect by wifi, but then they reported No internet connection
After checking network-manager ...
- 51