Questions tagged [firewall]
A Firewall is an application or hardware device used to inspect and filter network traffic.
4,178
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Can not start etcd cluster when setting up a HA K8S cluster
I am following this article to set up a HA k8s cluster:
Guide: Kubernetes Multi-Master HA Cluster with kubeadm
I have three master nodes(3,4,5) and four worker nodes(2,6,7,8) (one of the worker nodes ...
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iptables per-user split tunnel leaking udp packets
I followed the guide here:
https://gist.github.com/GAS85/4e40ece16ffa748e7138b9aa4c37ca52
I've added a couple more rules for local traffic, but my setup is still leaking udp packets, on ports not ...
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How do datacenter organize with their firewall/IDS,IPS(Snort,Suricata) rulesets [closed]
I wondered how massive datacenter or network's firewall or IDS/IPS rules are managed. I knew that generic firewall vendor like Palo Alto or Fortinet gives stock rulesets but I know that most ...
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VMWare ESXi Web Client access dies after some time
After applying IP filters on VMWare esxi's firewall settings for Web Access / Web Client rules, the allowed IPs work fine for some time like 5 hours.
Only the IP addresses I allow can access the ...
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Google Play logs for Windows devices [closed]
Looking at a firewall logs, I see lots of Windows Desktop devices connecting to play.google.com
I had thought that play.google.com was service for Android devices only.
Why would a windows device ...
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30
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Cannot 'sudo apt install <something>' after IPtables configuration
I'm trying to install some of the packages on Debian VM which is connected to another Debian machine (router). On the router default policy for FORWARD chain is DROP. I added rules for http(80), https(...
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How to apply DROP rule immediately (iptables/conntrack)
An external IP is connecting to my mailserver VM every second and I just want to block this IP immediately without dropping existing connections.
So I apply a DROP rule.
I even reloaded all the ...
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Block requests to "Visual Search" in Edge and "Search images with Google" in Chrome for internal web application
We have a web application that is used internally that displays highly confidential images.
Microsoft Edge has started displaying a button on the images that launches Visual Search, and Chrome has a ...
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Windows 10 not receiving multicast
I have an application that sends multicast packets to discover each other.
This works on most Windows PCs but I have found one PC where it doesn't work.
Here are the things I have noticed on the PC ...
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Cisco Firepower not routing correctly
I recently purchased a new cisco firepower firewall, but I've failed to get it to work as an internal gateway which routes all traffic to the BT Internet modem. How should I create an internal network ...
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I block ports using firewall still they are accessed
I am using Avast firewall. I blocked ports from 1024 to 55535 yet I see apps established connection on ports in that range.
As you can see on the screenshot, the machine is making mirror connection.
...
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97
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iptables rules not working for allowing a specific IP
I have a host with 2 network interfaces: wifi and site-site vpn (zerotier).
root@host:~# ifconfig wlp0s20f3
wlp0s20f3: flags=4163<UP,BROADCAST,RUNNING,MULTICAST> mtu 1500
inet 192.168.1....
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1
answer
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Cisco ASA to Watchguard
I have never worked with watchguard firebox firewalls in depth before and we are replacing a Cisco ASA 5515 with a Watchguard M390. I am having a hard time interpreting the configuration settings in ...
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Stop exe from accessing internet - firewall blocks but DNS request is being made
We purchased this software a few years ago, we use it locally only. After some update this software received the function to save user files on their cloud. For security purposes we would like to keep ...
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How exactly is docker circumventing my nftables?
My aim is to block all ports from non "lo" interfaces except for 22, 80, 443.
I don't want external devices to my Rasberry pi to be able to access anything else except for 22, 80, 443.
I ...
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Wireguard connection successful but no route from server to client
I set up wireguard on a server in my dmz following the official (and other) docs. The following figure shall illustrate the general setup, where wg0 is the virtual tunnel interface created by ...
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Filtering traffic by MAC - nftables
TL:DR : I am building a network tap with a raspberry-pi that must remains stealth. I have a bridge (br0) between the switch interface (eth0) and the workstation (eth1).
Here is how i am building it (...
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iptables rules for dsvpn
on github i'm looking at this vpn project called dsvpn. it sets up some firewall rules by running iptables commands. One of them is (i hope the names are self-explanatory) :
iptables -t raw -I ...
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17
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After setting a forwarding (routing) I cannot download files from servers
I have found these codes on www to create a proxy for a software:
sysctl net.ipv4.ip_forward=1
sysctl -w net.ipv4.ip_forward=1
iptables -t nat -A POSTROUTING -j MASQUERADE
iptables -t nat -A ...
- 101
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25
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troubleshooting dns resolution, packet dropping, and dig/nslookup
I've been trying to troubleshoot an issue where using a curl lookup command takes a long time (sometimes) and is quick some other time.
TL;DR
Question: how do i troubleshoot further.
Connecting ...
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46
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ConfigServer firewall enable SSH for dynamic dns
I am running ConfigServer Firewall on my server. Currently I have a few dynamic dns entries added to the LFD Dynamic DNS section. Those dyn dns hosts though cannot SSH to the server - I can only get ...
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2 VLANS on 1 Physical OpnSense Ethernet Port (connected to wifi access point) and 1 Captive Portals on each VLAN
I want to create a captive portal with different restriction per user account/role (student and teacher).
The Teacher can have unrestricted access.
The Student have restricted access. (only defined/...
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57
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fail2ban - one IP banned multiple times by multiple jails - errors in log durin unbanning
I make few similar jails for different ports...
jail names: http_https_deny, dns_deny, ftp_deny, smtp_pop3_deny, ssh_deny
here firewalld and fail2ban settings for http_https_deny(other almost same, ...
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45
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Firewall blocking Port
I am running multiple Webservices on my Ubuntu 22.04 Server and want them to bind to specific Ports which works without problem but when trying to connect it is not working and portchecker returned me ...
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Firewalld apply port redirection from rootless Podman containers to host
Is there a way to redirect ports for traffic that originates from the host or a Podman container and is destined for the host or another Podman container using Firewalld?
My use case: I am hosting a ...
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107
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Which is the appropriate service to allow an ip range to access API Gateway + Cloud Storage on Google Cloud?
I'm trying to identify the appropriate service to allow only a certain IP range to make requests to API Gateway and Cloud storage. This is because we only want to accept request coming from cloudflare....
google-cloud-platform
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105
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Apache2 http server and Openvpn server on the same machine
Installed Apache2 server on my Linux Mint 20.3 Cinnamon and I could easily reach my http pages from web pointing to the static ip address of my router where I have configured the right http port.
I ...
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I am unable to access services on the WAN IP from within the network
Normally, this would not be a desired configuration, but I am setting up a NextCloud server, and to validate the domain, it requires that it be able to access it through the public IP address. No ...
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Why does Windows 10 disconnects WIFI frequently, when Firewall is very restrictive?
On my Win 10, I've blocked all incoming/outgoing connections except: DHCP, DNS, LAN, Edge and couple other apps. After reboot Win 10 sees WiFi connection as connected/no internet => disconnects it ...
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How to create access point or virtual access point in Fedora server 37 to access localhost too
Hi I am trying to create an access point in ideal case virtual access point in Fedora server 37.
I can create a simple AP for wifi to LAN(wlp7s0 -> enp1s0 in my case) using these commands and I can ...
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32
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What needs to be open to the Internet for Office 2019 applications run smoothly?
In a tightly closed down environment, I have a linux machine acting as router with a fireHOL firewall (iptables), limitting not only inbound traffic, but also outbound traffic.
Office 2019 ...
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Create a BPF rule to only allow openvpn traffic to destination port 1194 and drop all other traffic including all other udp traffic
I am trying to create either an iptable or a BPF rule which will only allow Openvpn traffic over udp to my vpn server on destination port 1194 in the hopes of preventing ddos attacks to that port ...
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1
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Which ports are relevant for directing NFS traffic over iptables (or any other way) to a server behind a firewall server
I read that NFS v4 requires only port (2049). This is the post I relied on.
However, if I do a rpcinfo -p before starting nfs, I see:
rpcinfo -p
program vers proto port service
100000 4 tcp ...
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How to reverse tunnel over HTTP only firewall
I have a server ("A") running behind a firewall, which only serves HTTP (I kid you not). I have no control over the firewall, but "A" can connect to server "B", though ...
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1
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58
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IIS serving files - strange behavior
I will try to explain the problem as best I can.I have an IIS server that is accessible from outside and users use it to download files (.zip, .iso, etc.).
With smaller files, this is not noticeable, ...
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37
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Nginx: Accessing website by domain name will throw ERR_TIMED_OUT
Steps I did:
I've Debian VPS and I've bought domain "marek-prusa.dev" on Google Domains.
Steps how I configured my webserver with domain name "marek-prusa.dev".
I've created marek-...
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32
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Controlling virsh filters right way
I'm running centos 7, lxc for containers, virsh for setting up a bridge.
Upon creation, virsh set up some firewall rules for virbr
# iptables-save | grep virbr
-A POSTROUTING -o virbr0 -p udp -m udp --...
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107
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I am trying to set up a simple http server in port 8000 and connect remotely. UFW is open at 8000, but the connection is refused
I am new to networking and servers and I am trying to get started by setting up a simple server in port 8000 in a remote host with python -m http.server 8000 and telnet from my local computer
I've ...
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40
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Create iptable rule to match UDP traffic with multiple source ports and a single destination port
I am trying to create an iptable rule that will match multiple source ports and a single destination port. I have tried the following rule but am met with this error:
iptables -A INPUT -p udp -m ...
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No domain profile in Windows Defender Firewall
We've moved from an on site server to online at our company, and we've had our user profiles rebuilt on our PC's so that we use Azure based profiles instead of domain profiles. I'm having issues ...
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iptables with docker-user, release connections with the container itself
If the system that is inside the container tries to connect with MySQL from the container itself using the server ip (192.168.0.200) it does not connect.
The problem is in
iptables -P INPUT DROP
if ...
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1
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88
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Block IPs without receiving traffic
I'm hosting on OVH Game dedicated server, the bandwitdth of this server is 1gbp/s, I'm receinving attack from other OVH Servers and they are saturating the bandwidth with 1gbp/s.
OVH doesn't filter ...
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1
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77
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UFW not allowing specified ports
I have this
Status: active
Logging: on (low)
Default: allow (incoming), allow (outgoing), disabled (routed)
New profiles: skip
To Action From
-- --...
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Browsers can't make connection to my server without port 80 open
I have a server where NGINX is running as a reverse proxy. My configuration works fine when I leave ports 80 and 443 open on my router. When I only keep 443 on it, I have "Connection timed out&...
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34
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CSF Deny an IP Range Exclude specific IP on specific port
I've bunch of ips / networks added to csf.deny
csf.deny
1.1.0.0/19 # do not delete
However i want to allow 1.1.1.1 on port 80 and 443 with csf.allow
csf.allow
tcp|in|d=80|s=1.1.1.1
tcp|in|d=443|s=1.1....
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Can't set up the GCP's external load balancer to work correctly with Terraform
Using Terraform, I want to build an infrastructure that consists of an external load balancer (LB) and a MIG with 3 VMs. Each VM within the MIG should run a server that listens on 80. Furthermore, I ...
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1
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136
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Whitelisting Gmail SMTP in CSF
In my csf.deny, I have 0.0.0.0/0 blocked to prevent requests being sent to the raw server IP. This creates issues with sending e-mails. I utilize Google SMTP to send e-mail. I can't seem to figure out ...
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41
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How to use Laravel Forge when SSH is blocked
I'am trying to use Laravel Forge in a Ubuntu 22.04 Server with SSH is blocked. Laravel Forge is a server management software which requires SSH to connect and manage.
I found another similar service ...
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4
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395
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nftables firewall configuration on Rocky 9.1
I have installed K3s with Rancher on Rocky 9.1 machine.
According to the manual, firewalld must be turned off.
To turn off the firewalld, I performed:
systemctl disable firewalld
systemctl mask --now ...
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answers
20
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Is it valuable to do DNS Leak Testing directly from a firewall and not just from the client side?
I've been writing a tool that can be added as a package for pfSense, and essentially the tool allows you to perform a DNS leak test on any of the interfaces on the firewall appliance.
One developer I ...
