Questions tagged [firewall]
a technological barrier designed to prevent unauthorized or unwanted communications between computer networks or hosts
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How to match the --out-interface to the same --in-interface in iptables
The system have multiple interfaces: eth0, eth1, eth2, ... br0, br1, br2, ...etc.
The following rule will allow packets from "br0" to "br0":
iptables -A FORWARD -i br0 -o br0 -j ...
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Cannot establish HTTP connection with VPS although ufw is allowing outside traffic
Here is the output of sudo ufw status verbose
Status: active
Logging: on (low)
Default: deny (incoming), allow (outgoing), disabled (routed)
New profiles: skip
To Action ...
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Why Ubuntu 22.04 Network Manager sends messages to blackcat.canonical.com in two IP addresses?
Here are the netstat -tnp output captures from my Ubuntu 22.04 workstation. Why are there outbound NetworkManager connections established from time to time? What are they doing?
The IP addresses ...
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Ping IP Linux Ubuntu
PT-BR
Estou utilizando Ubuntu e preciso descobrir a latência de um IP de um subdomínio. Tentei primeiramente o comando "ping", mas sem sucesso. Também tentei chegar se a porta 53 e 80 ...
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apache2 on ubuntu 14 - localhost works but ip doesn't
I've just installed apache2 on my box, along with php5.
I can navigate to "localhost" and it works. But I can't access this webserver from another machine... or even locally using the IP ...
CommunityBot
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Firewall to white- or black-list incoming requests
Well over a decade ago, when I was a Windows user, I used a Kaspersky firewall that would pop up when an application wanted was receiving a connection and allow me to allow or deny such connections.
...
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Disable Internet access but allow chrome extension
I'm trying to deny access to the Internet and that part works with ufw default deny outgoing (the PC is going to be used for exams so no googling allowed;-))
But
I need access to a chrome extension ...
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SSH not working on port22 after checking open port, updating UFW, port fowarding on router and confirming internet carrier ports status with carrier
This is my first time trying to make an SSH tunnel. The purpose is to make an offsite backup our server (server A) in the office which is about 1 mile away.
I have set up all ports on the office ...
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2
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LXC container cannot ping 8.8.8.8 or other outside ip
I run a LXC container on my "Ubuntu 23.04" VM by UTM on my mac laptop
but I cannot ping 8.8.8.8 in my LXC container.
I downloaded lxc via snap
note: I have search many info to fix the ...
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3
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How to allow an IP (ipv6) address using ufw?
I'm using Ubuntu 16.04 LTS, and I want to block all connections except some IP addresses. I ran these commands
ufw default allow outgoing
ufw default deny incoming
ufw allow ssh
ufw enable
ufw allow ...
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Portforwarding Port 22 ( for ssh ) over JioFiber Router not working ( port 22 is closed )
I am using a JioFiber Router ( Firmware version : SRCMTF1_JCOW414_R2.52.1 ) . The host that I want to expose to the internet has Ubuntu Server 24.04.
Private IPs :
Router ...
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UFW not logging [UFW BLOCK] events when default is to allow incoming connections
I'm trying to get a message logged to /var/log/ufw.log when blocking packets. It's all working very well, until I change the default behaviour for incoming connections.
I use ufw default allow ...
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Firewall ufw to deny port visibility
How can I block ports from being visible/accessible from the outside using ufw?
If I nmap my server I can see all my running Docker containers (all ports from 8080 to 8086), which I do not want, ...
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ssh connection refused
Hi I'm having a problem with my ssh, which is magically stopped working and I couldn't figure out why. The message it give is:
ssh: connect to host <host> port 22: Connection refused
I don't ...
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Cannot start Ubuntu on WSL2
have a W10 device in test environment with clean WSL2 install, no distros. Installed Ubuntu. When attempting to launch I receive the error:
WslRegisterDistribution failed with error: 0x80072749
Error: ...
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SSH: Port 22 Connection refused
From Ubuntu 18 lts I'm trying to establish ssh connection with my Kali Linux VirtualBox on the same computer. I've already installed openssh-client and openssh-server on both systems and I'm connected ...
CommunityBot
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“No new release found” when upgrading from 16.04 to 18.04 LTS?
I'm trying to upgrade from 16.04 to 18.04 LTS. When I go to do-release-upgrade, though, I get a message "no new release found."
I've tried editing (or not editing) /update-manager/release-upgrades; I'...
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iptable-save command not showing any output
When i run iptables-save command on Ubuntu Ubuntu 22.04.3 LTS and Ubuntu 20.04.4 LTS it not showing default firewall chain rules when i run this other linux example centos or redhat i am able to see ...
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AXIOS/Fetch - Error on Ubuntu
Axios or Fetch data from external API Error on Ubuntu 22.04, but if using local API or try on my Windows, it can work.
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Completely remove ufw, delete all iptables chains and rules, for a fresh start with nftables firewall in Ubuntu MATE 19.04
Though I have gone through quite a few threads on AskUbuntu (1, 2, 3), and elsewhere, I'm little confuse on how to proceed.
I'd like to completely remove ufw, delete all iptables chains and rules, ...
CommunityBot
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2
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status ufw problem (exited)
I have a problem with the ufw (firewall) program that is running, but status is "Active: active (exited) since Wed 2019-02-13 14:56:25 +0330; 31min ago" can anyone help me the reason?
CommunityBot
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telnet: Unable to connect to remote host: Network is unreachable
I am not able to connect to gmail with telnet using any of the ports.
I am using this command:
telnet smtp.gmail.com 25
and it gives following error:
Trying 74.125.68.108...
Trying 74.125.68.109.....
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Ports show as open when nmaping to localhost but filtered when connecting to IP
My 22.04.4 Ubuntu server was installed on a Proxmox VE. Then I installed Discourse forum on top of it (it uses Docker).
Now, after successful installation the Docker's 443/80 ports show as closed when ...
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2
answers
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Can't connect to smtp.gmail.com on port 465 or 587
I have an Ubuntu 14.04 (Trusty Tahr) is mounted on AWS and i cannot connect to the SMTP GMail service vía:
SSL(465):
## $ telnet smtp.gmail.com 465 ##
Trying 74.125.28.109...
Trying 74.125.28.108...
...
CommunityBot
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1
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2013 - Lost connection to MySQL server at 'reading initial communication packet', system error: 0 "Internal error/check (Not system error)"
I have these users in MySQL
User
Host
debian-sys-maint
localhost
mysql.session
localhost
mysql.sys
localhost
root
localhost
I want to connect to it remotely from my mac via SSH
I can't connect. ...
CommunityBot
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1
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IP forwarding does not work
I have 2 Ubuntu systems , both have Ubuntu 20.04, one has server (5.4.0-42-generic) , the other has desktop (5.4.0-58-generic).
I can get ip forwarding working on one system which has the server .
But ...
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How to allow direct connection to plex media server
im trying to set up plex media server on ubuntu server os.
i installed the plex media server and when im trying to watch in the same network everything is ok.
the problem starts when i try to stream ...
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Graphic Issues Firewall gfuw in Ubuntu 22.04.4 on RPI4 8GB
I'm running ubuntu mate 22.04.4 LTS on my 8GB Raspberry Pi 4. After not using the device for some weeks I ran all updates and upgrades. I noticed that the VNC remote access was no longer working so I ...
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Jammy 22.04 Attaching a pro subscription
when I try to attach my UbuntuPro subscription it keeps failing with no real error message.
lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 22.04.4 LTS
...
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Unable connect via port knocking
I am trying to set up port knocking on my server to enhance security. I've configured my firewall rules to use port knocking, where I have to connect to specific ports in a specific sequence before ...
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1
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Cannot reach some WEB pages
A few weeks ago I was able to browse any WEB page from FireFox on my Ubuntu 20.04 desktop system. Now some WEB pages time out. For example, no problem accessing askubuntu.com, but I time out trying to ...
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LAN network with just two computer: All ports time out, except port 50002, which refuses connection. Why?
Preface and Context:
I am currently troubleshooting the ROS2/LAN based connection of my UR5 CB3 robotic arm with the Ubunut 22 control comupter and the respective driver. This robotic arm seems to ...
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Assistance Needed: Recovering Root Password and Accessing Firewall Settings on Ubuntu 20.04 Server
I am encountering issues with my Ubuntu 20.04 server running on Oracle, as I have forgotten the root password. Unfortunately, I am unable to access the GRUB menu to initiate password recovery. Could ...
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How do I configure persistent firewall settings in Ubuntu 22.04 LTS - confused about ufw, nfw and iptables(-nfw/-legacy)
TL;DR: how do I configure firewall rules to be persistent? I am not using UFW, I believe I am using iptables-nft.
First, I have
started from pretty recent vanilla Ubuntu 22.04LTS installation (some ...
CommunityBot
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2
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UFW rules disappear after manually adding them to user.rules?
I need to add rules to ufw by editing the user.rules for some reason, when I add rules to it and do sudo ufw reload, the rules are gone. Any reason why this happens and how can I add rules by manually ...
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0
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Why tor need icmp in outbound iptables?
I'm trying to block everything in outbound except tor with iptables.
But without enabling icmp tor doesn't work, it's very strange since tor don't use icmp as my understanding.
That's what I'm using ...
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firewall is enable but gufw wont lauch
The firewall is enabled. But I can't launch gufw interface.
sudo ufw status
Status: active
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6
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How do I get ufw to start on boot?
UFW is not starting for me on boot. My /etc/ufw/ufw.conf file looks like this:
# /etc/ufw/ufw.conf
#
# Set to yes to start on boot. If setting this remotely, be sure to add a rule
# to allow your ...
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1
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Port not open (ufw disabled)
On the server, running Ubuntu 22.04
sudo netstat -tnlp | grep :4000
tcp 0 0 0.0.0.0:4000 0.0.0.0:* LISTEN 10690/nxd
tcp6 0 0 :::4000 ...
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How to open port on wsl2 ubuntu of windows 11
To test the network between Windows 11 localhost and WSL2 ubuntu on Windows 11, I install tomcat9 on WSL2 ubuntu
$ sudo apt install tomcat9 -y
$ sudo systemctl enable tomcat9
$ sudo systemctl start ...
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2
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what happens if ufw firewall is inactive?
I want to know more of what ufw is. I'll ask some questions and you can let me know if i'm right or not.
ufw helps us to block connections or allow connections from specific ip address or whatever. I'...
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Where Can One Find Guidance for Managing a Firewall?
I have been searching to find information regarding managing firewall rules, but have found nothing.
I wish to be clear: I am NOT trying to learn the commands to modify iptables or ufw for example, ...
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1
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Use UFW (firewall) to deny incoming ping (ICMP) requests?
The ufw (uncomplicated firewall) command line app does not have any option for disabling incoming ICMP Internet protocol requests. ICMP is used mainly by ping to discover IP addresses of servers on ...
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Adding VPN exception (allow protocol) to UFW firewall rules?
I'm having trouble at work in connecting to the work VPN while Firewall (UFW) is active. When i disable it "sudo ufw disable", there are no problems.
When it's on, when trying to connect I receive ...
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See configured rules even when inactive
I'm wondering if it's possible to get UFW to list the configured firewall rules even when it's not enabled. I only have ssh access to the server at this time, and I don't want to enable UFW if there's ...
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Connection refused from localhost in wsl2 ubuntu
I try to test connection between windows 11 and wsl2 ubuntu in windows 11. First I install nginx on wsl2 ubuntu and type in 'localhost' on web browser on windows 11 . The connection is successful. And ...
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ufw won't put custom rule in the correct place at reboot
My general issue is that I lose contact with my Ubuntu 23.10 on ssh once I close my ports using knockd. I would like for it to maintain existing connections.
I have a custom rule
> iptables -I ...
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Specify L2TP VPN to use other port
I am currently at a hotel and they seem to block VPN use. I assume they block it by looking into the port it uses.
I would like to use my company VPN (L2TP). So, I think my best bet is to change the ...
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How to enable communication between 'software' netplan configured vlans
I have searched far and wide so I if it looks like I have no idea what i'm doing, that is because it is a correct assumpstion. Usually we do this ourselves with our MikroTik router setup. We have a ...
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What are the use cases of "continue" verdict in the nftables?
It is described in the documentation of nftables as:
continue
Continue ruleset evaluation with the next rule.
This is the default behaviour in case a rule issues no verdict.
But I am ...
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