Questions tagged [firewall]
A Firewall is an application or hardware device used to inspect and filter network traffic.
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iptables adding localhost once adds the rule twice
I am trying to whitelist memcached port 11211 on ipv4 with iptables v1.8.4:
iptables -A INPUT -p tcp --dport 11211 -s localhost -j ACCEPT;
Whenever I run that command, then listing the rules, that ...
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Issue understanding subnetting and connection issues
I am in the process of planning a network overhaul and have run into a small problem with my logic.
I have setup a new VLAN in our VMWare, switch and firewall, and deployed som virtual machines for ...
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Firewall is blocking incoming responses in Google Cloud Function
My Google Cloud Function is connected with a Static IP Address. It is making API calls to Adobe Reactor API and Jira API. Jira API requires a static IP address. Adobe Reactor API doesn't necessarily ...
google-cloud-platform
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Server A not receiving UDP traffic on port 5060 from Server B
I have sip traffic which needs to flow bidirectionally between server A and server B on port 5060.
I have tried running netcat on both the machines
Netcat from machine A to B:
========================...
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User-defined docker network not automatically added to firewalld zone preventing container to container communication
I have recently (blindly) upgraded my homelab server which lead to some unfortunate side effects. I cannot make two containers on the same network talk to each other anymore when firewalld is enabled. ...
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How do I configure a second WAN port to connect to a /29 network provided at a Data Centre?
The data centre are providing a host range (xx.xx.xx.204)-(xx.xx.xx.206) with a network: xx.xx.xx.200/29) for internet connectivity.
I can connect one of the three physical ports we have been provided ...
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Intermittent Network Printer Issues with Kyocera Devices Across VLANs
We're experiencing an intermittent issue with our network printers (primarily Kyocera) in our company. The problem is that the printers randomly stop working for certain users on a day-to-day basis. ...
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What security issues could arise from allowing only specific IP access to an open port using UFW on Ubuntu?
I have two hosts running Ubuntu 24.04: Host A and Host B.
On Host B, I have an application that listens on port 7000.
I want to securely connect to this application from Host A while preventing access ...
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iptables forgets states after losing carrier
I have an issue with linux firewall, looks like it forgets states right after physical connection goes down.
There is an established ssh session, but firewall starts dropping packets after connection ...
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How Can I Configure Mac OS Packet Filer (pf.conf) to Reroute trafic From 1 Port to another while allowing both ports to communicate?
I'm trying to configure my macs (Monterey) packet filter rules to reroute traffic headed to port 8090 (php ratchet server) to go to port 8091 (php socket server). From there the socket server (8091) ...
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Domain Controller/DNS Server lost ping connection to my Sonicwall Router
I hope you can help me identify what is possibly happening on my network.
I have my ISP modem, then I connect a small 4-port switch (just for test ISP connection in case of internet issues), from here ...
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How to allow traffic to a specific external address in EdgeRouter?
I'm trying to set up EdgeRouter to filter traffic for IoT devices. I connect the devices to a separate VLAN, and I have so far set up the rules for this VLAN to only allow the devices to connect to my ...
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Why does port 8443 work, and port 4223 doesn't?
I implemented a https server and a wss server using NetCoreServer in DotNet8.0
When i run the server(s) in a local virtualbox, and access it by its extern ip, everything works fine.
I now uploaded the ...
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HTTP server is not responding From Outside although firewall is inactive
I have a VPS which has Ubuntu 20.04. When I request the server from inside(when I have active shell) using http -vv GET http://216.10.242.221 it gives proper response. But when I request from outside (...
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how to open 3389 TCP on CSF for Remote Desktop Connection in CentOS 7?
Recently I installed CSF and disabled firewalld on centos 7
when it was on firewalld there was no problem with remote connection
but now I'm not able to connect throught remote desktop because of CSF ...
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nftables restrict access between date and time
Documentation of nftables about match concept is too weak .
nftables document
I want accept all traffic from ip x.w.y.z with port 80 only between two Date & Time for example :
start : 2024/01/12 ...
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Fortigate 40F syslog over TCP not working, but UDP works
Trying to send syslog over TCP from Fortigate 40F does not work, but it works over UDP.
The config for the syslogd settings are:
config log syslogd setting
set status enable
set server "...
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How do I apply src-nat to the traffic coming from ipsec?
I am using StrongSwan to Mikrotik IKEv2 tunnel. I wonder if it is possible to sourcenat what is comming from the ipsec-tunnel on Mikrotik's side?
The problem is that I have a host in my local network ...
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Local Group Policy firewall rules not listed in GPO firewall
I have 100+ rules defined as per LGP. I can see all these rules both in Local Windows Firewall in RO mode as well as in HKLM\SOFTWARE\Policies\Microsoft\WindowsFirewall\FirewallRules. I also can see ...
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Can't transfer file via tftp, ERROR - Failed to open file 'file' on server
The Debian computer connected to router, router connected to a modem, router ip 192.168.10.1, modem IP addr 192.168.100.1 and computer IP addr 192.168.10.106. I want to transfer file from modem IP to ...
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Block all IP addresses except specific IP range (firewall-cmd)
Port has been "opened" with following commnad:
firewall-cmd --permanent --zone=public --add-port=80/tcp --add-port=80/udp
Now the service on port 80 could be used by any IP in the whole ...
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icmp echo reply not sent over wireguard tunnel
I just setup a Wireguard instance on an opnsense firewall with a public IP. I set this up by following the Opnsense Road Warrior Wireguard guide.
The issue that I am running into is that icmp echo ...
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SSH session over ipv6 hangs after short time, works fine over ipv4
I have set up a server and a router (two machines) with both ipv4 and ipv6 (ULA).
Ubuntu Version: 24.04.
When using ipv4 for both ssh and cockpit everything works fine.
When using ipv6 following ...
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I tried installing pfsense as a virtual machine on hyper-V , however i am not able to connect it over LAN to other Vms on the hyper-V
I set up a WAN and LAN for PFsense and LAN on other windows virtual machine. I gave the pfsense LAN as gateway address of Virtual LAN. I am not able to connect to internet over LAN.
I set IP Address ...
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358
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Abuse complaints on my Hetzner VPS
I have a Hetzner VPS and received an abuse complaint from a website owner that Hetzner forwarded to me. There have been a significant number of connections from multiple IP addresses from my server ...
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"Network error: software caused connection abort"
I am experiencing a persistent issue when using PuTTY. I can logon to my ubuntu server, but after 5 minutes the connection is terminated with the following message:
"network error: software ...
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Single IP timeout from single machine - local network stack messed up?
We have one Windows 10 laptop that times out connecting to a certain website on port 80 and 443.
A second webserver by the same company in the same subnet is reachable.
ping and tracert to this IP ...
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csf -d <IP> will block an IP for a while but then it is somehow gone again from the csf.deny list some time later
I keep seeing the same attacker in my apache logs ffrom the same two IP addresses. I block both the IPs using the command
csf -d <IP>
Then I check the /etc/csf/csf.deny file and those two new ...
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WireGuard tunnel on Mikrotik working "one way"
I have two remote locations.
Location 1: MKT-KRK - Mikrotik with public IP (11.12.13.14)
Location 2: MKT-BRZ - Mikrotik - no public IP
R1 - BRZ - public IP (15.16.17.18)
Network diagram below:
...
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Unable to connect to WhatsApp messages in low bandwidth 22kbps uplink and 88kbps downlink from router even internet is connected
We are working on low bandwidth environment with 22kbps uplink and 88kbps downlink. Configured Router with iptables to deny all the traffic and allow on WhatsApp domains, ports and IP's.
We were able ...
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242
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AlmaLinux blocking outgoing connections
I have a new AlmaLinux installation that is blocking outgoing connections to most ports, with the exception of a handful. I notice this mostly because the server runs Exim and no e-mail can be sent on ...
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“Difficulty Accessing Redesigned Website from Local Network - How to Resolve 404 Error
Description:
I recently redesigned our website and migrated it from Namecheap hosting to Hostinger. While the updated design is accessible from external networks when hosted on Namecheap, I’m ...
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Firewalld: adding a source IP blocks SSH. Different behaviour between versions?
I have two servers with different versions of RHEL and firewalld. Both are configured the same, but they are behaving differently when I add a source IP to a zone.
Server A:
# cat /etc/redhat-release
...
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How to block Web3 Domains
There are some domains called "decentralized" (Web3), promoted by Unstoppable Domains and Ethereum Name Service, example:
.888
.anime
.bitcoin
.blockchain
.coin
.crypto
.dao
.eth
Is there ...
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ExtremeCloud IQ schedule a task
Is it possible to make a task to schedule a automatic update to all APs every ones in the 3 months? And reboot at night 3 aclock?enter image description here
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UFW -- Will placing a specific IP above a CIDR allow that IP superseding the CIDR deny?
I cannot reliably get results from my testing .. But if I had said rules in this order:
zak@Web:~$sudo ufw status
Status: active
To Action From
-- ...
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Better way to block IP Addresses with an Azure VM
I am using Azure for my virtual machines and it gives you a way to block IP addresses in the Network Security Group. However this IP list is getting quite long. Is there a better option to do than ...
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Wireguard and Ubuntu 22.04. Forcing traffic from port 25 over VPN
So Im hosting a server in a docker container which is a client in a VPN network. I Cant send any egress traffic out of port (say ummm 52) through the host. That box is a client to a wireguard server. ...
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FortiGate and WireGuard UDP hole punching
I am working on a project that uses WireGuard and UDP Hole Punching to create a mesh network between peers. The peers are mostly behind residential home gateways where the hole-punched tunnels work ...
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how to reset asmb8-ikvm firewall
Due to a misconfiguration of the firewall, I am currently unable to access the IPMI of the local server（Asus p10s-i）.
When executing ipmicfg -fd 2, I receive the error message "command not ...
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Wireguard clients can not KDE connect between peers
I succesfully established a Wireguard VPN from a Rocky Linux 9 server at the cloud. As of now there are two clients: a Fedora desktop and an Android mobile phone. The first problem I want to solve is ...
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How to disable Network Interface for SSH?
In my linux machine, I have 10 network interfaces available like eth0, eth0.67, eth0.70, eth0.97 etc,.
When i run the command nc 160.48.249.170 22 to check, i get like below:
root@icon:~# nc 160.48....
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How to put multiple VMs behind a single *private* IP address on Azure?
I'm working on creating a Blue/Green deployment for a product in Azure but I'm running into a problem regarding outbound traffic to an on-premisses database.
Our initial idea can be seen in this ...
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fail2ban iptables REJECT rules not working [duplicate]
I managed to setup fail2ban and monitor my mysql database logs because I am being brute force attacked through my database login. the database is in a docker container and fail2ban is on the host ...
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Screened subnet implementation and nat
I'm trying to implement a screened subnet but I don't know which is the right way to do it.
Is it correct to have both internal and external routers doing NAT (IP Masquerading), while internal one ...
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How do i stop packet flooding on my server? [duplicate]
I use a debian server to host my site, but i've found about this vulnerability in it that it could receive half the packets in a packet flood with this command,
ping -s <size of packet in bytes> ...
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Outbound IPv6 connection replies not routed back to firewall in VPC
In a newly-built AWS VPC (deployed with Terraform to minimise typos), I have one "DMZ" subnet and one internal. A firewall appliance bridges the two, with an interface in each. Both ...
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How to catch process being blocked by outbound iptables fw? [duplicate]
NOTE: Thanks for suggesting answers. I'd dispute this is actually a duplicate, but hey. The main issue (as stated below) which the suggested answers don't seem to address is that outbound iptables ...
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Connection to host reset when accessed via VPN or behind corporate firewalls
A client of mine was reporting connectivity issues from a lot of his customers who are either accessing his website from behind a corporate firewall or via VPN recently.
I did check the endpoint it ...
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Bypass nftables drop rule
tldr; bridge (see below) doesn't work if there is a matching drop in another table (like the default rules of firewalld).
Hello,
I'm building my own VM lib (kind of quickemu).
I have a problem with ...
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