Newest firewall Questions

Q&A for system and network administrators

Web Filtering solution - Recommendations [closed]

I'm looking for a way to selectively allow access to specific sites (URLs, domain names, IP Address) from my network to the Internet block all other communications. Any hardware recommendations for ...

Firewall (VyOS) block p2p

I have VyOS router, I want to block p2p traffic. Which ports must be blocked?. I tried 6881-6999, but it does not work. Thank you in advance for your help set firewall name "FIREWALL-IN" set ...

nginx IF statement matches with non-alphanumerical characters

I'm trying to stop some pesky bots by blocking ther user agents in nginx. What is the best way to put multiple user-agents/matches in the same if statement when they have non-alphanumerical characters ...

How to have network sharing between a lan to wan Firewall Setup?

I have a Dlink Router wherein one its LAN ports are connected to a Gajshield Firewalls wan port. The firewall has a Static Wan IP assigned to it from the Dlink LAN network. There is a inbound policy ...

What does “Security” mean in a GPO for Inbound Firewall Rules?

My environment is Windows Server 2012 R2 AD DCs with Windows 10 Pro clients. I have small, simple GPO which sets up Inbound Firewall Rules in: Computer Configuration -> Policies -> Windows ...

Apache not receiving packets. tcpdump shows them

Having an AWS EC2 instance in VPC, trying to add a secondary ENI to it. The interface has been successfully added with a security group I'm currently using for my primary instance ENI. Then a new ...

To connect to my server I'm forced to use iptables -F [duplicate]

To understand better please look this short video I can not solve a problem about a problem of dialogue between iptables and security group of EC2 The only way to connect to server using my elastic ...

Why is ip6tables not matching TCP traffic with -p tcp?

Yesterday I helped someone setup an iptables firewall in Ubuntu and it went smooth for IPv4 with normal iptables. He cares about IPv6 also and wanted a firewall for that. Things with ip6tables I ...

firewalld rich-rule equivalent in ufw

For controlling iptables, I stopped using firewalld and I use ufw instead. I need to apply these rules, but using ufw: firewall-cmd --zone=dmz --permanent --add-rich-rule='rule protocol value="esp" ...

Parallels and virtual firewall appliance between guest and host

I am wondering if it is possible to run a VM (Linux) from Parallels using host only mode in which the VM in question is networked with a second VM/firewall (pfsense) and detached, so to speak, from ...

Port forwarding on Fortigate 60D

I'm new to this type of equipment and am having a hard time port forwarding on my Fortinet Fortigate 60D. Here are my settings: wan1 (direct to ISP modem): X.X.X.142 internal (hardware switch): 192....

Can not connect ufw/iptables forwarded ports from external ip

I was forward my port 25 to 53525 in my server using ufw and iptable configuration. (ubuntu 14.04) It is testable port by telnet command, so I did try test it. Connection is well to my 25 port in ...

Real meaning of “in” and “out” regarding a virtual network

I am confused, I thought I understand those basics but now I'm not quite sure any more... Considering that conf : cloned_interfaces="lo7" ifconfig_bce0="dhcp" ifconfig_bce0_alias0="inet 192.168.0.1/...

Cisco RV325 - Error Policy Violation in Log

We are seeing new error logs when clients are trying to connect to our Cisco RV325 router. 2017-02-22, 06:09:30 Connection Refused - Policy violation IN=eth0 OUT=eth1 SRC=192.168.2.190 DST=72....

Why are my iptables rules too restrictive?

I want to tunnel connections to a openvpn server with iptables. I am connected with eth0 and have created virtual interface tun1 with IP 10.8.0.3. Why would the following iptables rules be too ...

Mac receiving ICMP requests but not sending any replies [migrated]

Why could my osx machine be receiving ICMP requests (that I'm sending), but not returning any replies? $ sudo tcpdump -nni any icmp tcpdump: data link type PKTAP tcpdump: verbose output suppressed, ...

ipset rules being ignored when blocking Amazon Web Services

I'm downloading the list of CIDRs for Amazon Web Services here: https://ip-ranges.amazonaws.com/ip-ranges.json And then putting them on a ipset with the line: sudo ipset -q -A tor $ip And blocking ...

Only all VPN traffic by MAC except on specific port

I have a device on my network that can only get to the outside world via VPN. I use an OpenWRT router with two VLANs: 192.168.2.X: All devices including the one in question 192.168.3.X: Isolated ...

Virtual network interface for DMZ [closed]

here is the situation. I have a laptop with two physical network interfaces: eth0 and wlan0. As an exercise i am doing some experiments with iptables firewalling, at the moment i receive internet ...

iptables show just one chain

tldr: How can I get iptables to show just one chain? I can have iptables show just one table, but a table consists of multiple chains. I need to find where in chain INPUT is the last rule (usually ...

iptables match forwarded packet if src address is in same network as dst address

I am looking for a way in iptables to match forwarded packets where the source address is in the same network as the destination address, without specifying the network. Of course, when I specify the ...

Properly manage iptables rules on Docker host

I am using Gentoo and Docker. I have bunch of own iptables rules, and keep them in /var/lib/iptables/rules-save. Docker adding bunch of own rules when start. It seems that iptables is auto-saving ...

centos 7 not allowing inbound tcp connection on port 80 when connected to two network interfaces

I connected two network interfaces to a server running centOS 7 and I configured the public zone to allow inbound tcp connections on port 80 & 443, I then set one of the network interfaces to the ...

google cloud firewall rule not working

I have a google cloud server with tomcat installation on port 8080. I can open the tomcat and deployed application in the browser from the google cloud instance but even after adding the firewall ...

PPTP Passthrough Centos 7/Firewalld router to Windows Server

I have a Centos 7 server running firewalld to allow public services to access internal services on a separate VLAN (dual NICs). I imported a Windows VM but I do not know what rules I need to put in ...

Site-to-site VPN disconnecting every minute

I have a static ipsec tunnel configured between a Sonicwall TZ105 and a ZyWall USG20W. The problem i am having is that the vpn tunnel goes down every minute and then establishes the tunnel again ...

OpenVPN server configuration to get through firewall

I am having trouble staying connected to my OpenVPN server that I configured on EC2. When connecting through obfsproxy, the TCP connection is established, the handshake works and it gets to the ...

Windows Server 2012 after power outage

Had a power outage, server restarted normally. Server is a database server for a hotel, which is connected to an ISP with optic fibre. On the restart, network went public, instead of the default ...

Docker stops working eventually when APF firewall is running

I have a CentOS 6 server. It has cPanel, Docker and APF firewall among other things. I leave the server for several hours, come back and run this command: [/opt]# docker run --name artifactory \ &...

How to open a port on CentOS 7 when firewallD is not running?

I am trying to set up PacketFence, but the switch is comunicating on ports 1812 and 1813. I had made a fresh install of CentOS 7 and now I need to open the ports - I did some research but everyone ...

Firewall rules in GCE not being applied (can't SSH,RDP or telnet to any ports)

I've recently been unable to log in to newly created Google Compute Engine instances in zone us-east1-d. It doesn't make a difference if they're Linux or Windows instances. I can't SSH, RDP or get a ...

Sending mail (via java) is working in eclipse but not in linux server

I am using java code to send a mail using smtp.gmail.com as smtp host. This code was working fine. But after a firewall upgrade in linux, its started to throw this error everytime I try to send mail. ...

PFSense IPv4 TCP/UDP connections from LAN not connecting

I have a PFSense firewall sitting as a gateway for a group of VM's sitting on top of a Xen hypervisor (all machines except for the host are virtual). I have PFSense acting as a waypoint for me to be ...

FirewallD - Trusted Zones / Drop Zone and Tracerouting

Im using CentOS 7 and I have an issue where I am trying to lock down a server to only accept SSH from any private IP ranges of 10.0.0.0/8 which is in the work zone, and 10.0.20.0/24 for any connection ...

What happens if you have same jails in Fail2Ban?

I have two jails in Fail2Ban: Jail #1: enabled = true filter = postfix-sasl action = iptables-allports[blocktype="REJECT --reject-with icmp-port-unreachable", protocol="tcp", name="default", chain=...

Firewall does not let me ssh into server

I am trying to access my Ubuntu 16.04 server which is online, but the issue I run into is: ssh: connect to host xx.xx.xx.xx port 22: Operation timed out I reenabled the firewall prior so I believe ...

is there any real Difference between snort and suricata?

Looking to move forward in deploying IDS/IPS on several FreeBSD firewalls and I was curious about the difference between snort and suricata. I know that Suricata is multi-threaded but in terms of rule ...

iptables to allow FTP only over VPN

I have defined this iptables chain: iptables -N VPNonly # create a new chain "VPNonly" iptables -A VPNonly -i lo -j ACCEPT # allow localhost iptables -A VPNonly --src xxx.xxx.xxx.xxx -j ACCEPT # ...

Override Microsoft HTTPAPI 2.0

I would like to override port 80 that use by IIS, try to stop application server but port 80 still use by Microsoft HTTPAPI 2.0 with pid 4 but cannot find it on task manager, I would like to achieve (...

Virtualbox: Testing Firewall rules between Host and Guest

I am testing a Sophos XG Firewall as a VM with VirtualBox 5.1.16 (on my Linux Mint), but I need that the FW rules that I create in the VM, affect my host, so I can see if the rules work or not. Is ...

How to block client request in Local Area Network in linux? [closed]

we have a Linux based Local Area Networking, Please find the below architecture diagram we have server and client machine connected to through network switch, When any request comes from client we ...

Firewall Ports + HaProxy

Using HaProxy as a SSH load balancer, We have HaProxy running in IP1:2222 and redirecting to IP1:2223-2233 and IP2:2223-2233. In this case, do I need to open Firewall Ports from Source IP:2222,2223-...

Windows Networking Setup

I work at a small veterinary business, and because I am the only one with any technical background I have defaulted into being our poor excuse for a sysadmin. I don't know enough about networking, but ...

understand the logic in creating a policy

I'm not very familiar with firewalls. I have a "Fortigate 90d". I must simply prohibit access to the internet to a group of about twenty pc. This ban must be made by mac address. I add a clarification:...

Firewalld CentOS 7 Routing IPv6

I try to set up a Centos 7 VM to route IPv6 traffic to another, interal Centos 7 VM. If i disable firewalld, all works, but that should not be the solution.. I've two interfaces: ens32 external (...

Routing OpenVPN exit traffic to multiple interfaces

I have two Debian servers that I am trying to configure, one is an OpenVPN server and the second is a mail server. I would like to configure the OpenVPN server so that it routes traffic from my ...

kubectl: The connection to the server XXX.XXX.XXXXXX was refused

I am trying to connect to kubernetes master (cluster) in Google Cloud Engine. The error that always I get when the kubectl try to access to kubernetes master is: The connection to the server XXX....

How do you port forward packets coming from a tunnel on a VPN Client?

I have a network of OpenVPN clients where I wish to open a port that forwards traffic coming from the OpenVPN Server to another device connected to the client. The client is a router running OpenWRT ...

What is the purpose of denying specific inbound traffic in firewalls?

Many common firewall rules include a number of lines that block specific inbound traffic. Take this from ipfw for example: # Fragments $cmd 00420 deny all from any to any frag in via $pif # ACK ...

Apache server sometimes return 500 but fixed after refresh

I have a wordpress website hosted by a Apache HTTP Server. This website previously works normally but recently it sometimes return 500 and says: This page isn’t working xxx.xxx.xxx is currently ...
Translating... 0%