A Firewall is an application or hardware device used to inspect and filter network traffic.

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1answer
13 views

Port 8080 remains closed even when opened with iptable and nodejs is listening on it

I am trying to install a nodejs server listening to port 8080 that I opened with iptable but when I run nmap or a web tools I always get the message that the port is closed. I'm on a Ubuntu vps. I'm ...
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0answers
25 views

Chinese Firewall DDoS and IPtables not working

Recently my server has been hit with DDoS's coming from the Great Chinese Firewall. As per the advice in one of the replies in mod_security block requests by http-host header, and the advice in ...
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0answers
18 views

IPTABLES and GEOIP: Show Custom Webpage to Blocked Visitors

Because of legal protection, as a first stage of launching my project I will focus on couple of countries only. The number of supported countries will grow. I know, it is possible to block or allow ...
0
votes
1answer
10 views

Do I need to set rules for source and destination ports for outgoing rules on iptables?

I'm using puppetlabs firewall module and I'm having troubles setting up iptables for a simple web host. I'm following this guide and want to set up additional rules. ...
0
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1answer
10 views

Concurrent connections per IP

I need to make a few changes to a firewall configuration, but before I do I'd like to see the number of concurrent Apache connections per IP. This command produces a nice list: #netstat -ntu | awk ...
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votes
3answers
54 views

How I can Block all China to entry to my server [on hold]

How I can Block China to entry to my server ? All China country ? By ipset and iptables I want by this to avoid DDOS attacks OS: CentOS 6.6 Thanks.
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votes
1answer
15 views

Does Sophos firewall support outgoing FTPS connections?

Is it possible to connect through a Sophos firewall to an external FTPS server? With FileZilla and connection mode "Require explicit FTP over TLS", the log shows: Status: Connecting to x.x.x.x:21... ...
2
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0answers
27 views

Iptables content blocking firewall

I have setup a firewall with iptables to ratelimit connections based on content. The following is an example of one of my rules that stops wordpress bruteforce attacks. `iptables -A INPUT -p tcp -m ...
49
votes
5answers
6k views

I accidentaly forbid SSH connection to a remote server… What's next?

Let's say it again, we all make mistakes, and I have just made one. A brief history: I was doing some stuff on a VPS (Debian) I'm renting, when I noticed some strange behaviour. Using the netstat ...
2
votes
1answer
18 views

Load average increasing along with firewall throughput

I've just pushed a large change to my backend code and I've noticed a massive increase in the load average in the few hours since the push. I looked at Munin for what the problem might be and I ...
2
votes
2answers
44 views

How to open port for a specific IP address with firewall-cmd on CentOS?

I would like to open port 4567 for the IP address 1.2.3.4 with the firewall-cmd command on a CentOS 7.1 server. How can I achieve this, as the documentation I could find was too specific on this?
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2answers
33 views

iptables block client ip internet access and keep LAN access

With the increase of appliances having network access and the potential for hacking, I want to block specific ip address from accessing the internet, but allow LAN access. For instance, I use a ...
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0answers
12 views

Route traffic to internal device on local address for internal clients

There is no DNS server at the site, so the URL is always resolved to an external address on the Firewall. Hence traffic originates on the local network, goes out the firewall and cannot connect to the ...
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votes
3answers
39 views

Why can i not ping my host behind the firewall. Cisco asa 5505 [on hold]

Can anyone please help me to figure out what in my configuration of the Cisco asa 5505 is wrong or missing. I have multiple host behind my firewall these hosts run different websites on port 80. I am ...
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votes
2answers
48 views

Resolve external DNS entries conditionally by request network source [closed]

I recently set up Sophos UTM as public firewall/ALG which I use for all kinds of things, such as VPN server, reverse proxy. When I tried configuring the DNS for my external domains, I had to notice ...
3
votes
1answer
24 views

Is the use of the RELATED state in iptables used properly?

I have been seeing many people using the ESTABLISHED and RELATED flags together to ACCEPT traffic through once a connection was previously accepted (see Allowing Established Sessions). Say I setup my ...
1
vote
1answer
19 views

Using two openvpn clients to expose services of a server

I am currently attempting to use two openvpn clients to expose services of a server, as is already said in the title. I may be playing with powers far beyond my current comprehension, but please bear ...
0
votes
1answer
32 views

How to enable firewall on Centos 7?

My firewall is currently inactive. systemctl status firewalld firewalld.service Loaded: masked (/dev/null) Active: inactive (dead) I used the following command to enable the firewall # systemctl ...
0
votes
1answer
27 views

How to setup monitoring of nodes behind firewall

As lame as it may sound: I am trying to configure monitoring for our production system which consists of 2 hardware boxes with ESXi on both and multiple VMs. All of this is hidden behind a firewall ...
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0answers
19 views

Remote packet capturing using fifo and dumpcap

I'm currently working on two linux servers where one server is running in 2.6.18-274.el5(Server A) and the second one in CentOS 7 (Server B). My requirement is to capture the packets of the network ...
3
votes
1answer
38 views

Nmap external scan shows port open, ASA says port is not open, but do get an socket

Folks, have a weird one, need your expert help. For one of our heavily used external facing server which came up in an audit, nmap -Pn scan shows the following: Starting Nmap 5.51 ... Host ...
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vote
0answers
9 views

Firebox x700 Reset to Default Not Working

I found a site that explains how to reset a Firebox 700 series back to default as you can see from this link: https://www.hashdoc.com/documents/7502/how-to-default-a-watchguard-firebox-700-or-x700 ...
2
votes
0answers
26 views

Solving an asymetric HA Firewall/router

I have an old Linux HA firewall/router setup that never quite worked. As it was never quite put into true production (just testing and demo's), I always had to have one firewall shutdown to make it ...
0
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0answers
17 views

iptables, after specifying an interface to drop traffic it drops all traffic of all interfaces

We have currently the situation that one interface (eth0) is linked to the internet. and we 2 other devices (eth1/eth2) for management purposes. Now the idea is to block off eth0 completely from the ...
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0answers
7 views

Open ports in firewall on Cisco SRP500 Series?

I have a Cisco SRP527W. I cannot work out how to open ports in the firewall for all machines. In the past, I port forwarded to the server, but now I just want a port open to all users of the network. ...
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2answers
43 views

How do I drop requests from dig?

Basically I'm getting tons of request to my named/bind service, basically those requests are being rejected by named, Those are the messages i get, from tons of ips., How extacly can I drop those ...
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0answers
9 views

Block ICMP flood from a specific IP with pf [migrated]

I'm getting a lot of ICMP throttle messages in my system.log: Apr 11 20:45:28 kernel[0]: Limiting icmp unreach response from 1054 to 250 packets per second Apr 11 20:45:29 kernel[0]: Limiting icmp ...
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0answers
20 views

Synology ssh port receiving too many intrusion attacks, how to ban systematically? [migrated]

I have a synology NAS which I leave at home, and leave it open so I can access it remotely from the office. One of the useful things to do is enable the ssh port so I can access it with my terminal. ...
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0answers
25 views

pfsense routing with dmz wan and sonic wall

Pfsense setup: 2 physical NIC's (1 input from modem/ISP, 1 LAN with a lot of vlans and DMZ) Network setup: WAN block from ISP xxx.xxx.xxx.225/28 Modem -> pfsense -> vlan 40 (192.168.40.0/24) ...
0
votes
1answer
95 views

No response from a remote linux server on specified ports

I have a remote CentOS 6.5 server that is running a tomcat 8 web server (AKA servlet) on port 54321 and I can't access it from my computer, although I'm establishing a successful SSH connection ...
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votes
2answers
59 views

Ubuntu Iptables Dual Wan - Forward wan 1 & 2 to an internal server

I'm having problems configuring iptables rules on a double wan setup. The OS is Ubuntu 12.04 LTS. I have 2 Wan connections, both with static IP. Wan-1 is on eth2, Wan-2 is on eth4. I want both of ...
2
votes
1answer
29 views

With SonicWall, cannot access URL inside network

We have a website running on port 80 on our network. Port 80 is forwarded outside of the network, and it is accessible through a URL that points to the IP or the IP itself. However, inside the ...
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0answers
45 views

ubuntu firewall blocking smtp tasks, port 465 is open

I have been trying to get my Wordpress site able to send emails, and it DOES WORK but only work if I turn off the firewall. I am using UFW. However, I do have port 465 (connecting to gmail) open while ...
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votes
2answers
41 views

IPTables not blocking IPStresser [closed]

I have been trying four days to block DDoS attacks with no success. I want to block anything that isn't whitelisted. This is my idea on OS Centos 7: //Delete All Existing Rules iptables --flush ...
1
vote
4answers
128 views

Cisco ASA Implicit rule dropping traffic

The network is as follows: Two Default Gateways exist on the network - one which provides connectivity to the an MPLS with several subnets. Let's say 10.0.0.2 Another which is a Cisco Firewall, on ...
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votes
1answer
41 views

Multiple Gateways on LAN

This is more a theoretical question. Let's assume we have a Firewall/DG (with a connected WAN) on LAN IP 192.168.1.1. All external DNS records for incoming services like OWA, FTP etc. point to this ...
0
votes
1answer
24 views

Web app architecture - firewall blocking

I'm currently working on a web app and seem to be having a few problems with the app being blocked by office firewalls of our test groups. My background is in design / front end so my knowledge of ...
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votes
0answers
14 views

Sonicwall seems to be blocking port 3690 on random internal up address

We are trying to connect to a clients subversion server over the internet using port 3690 and random internal ip address are getting blocked and time out all of a sudden. My local ip of 192.168.0.150 ...
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votes
2answers
46 views

How to restrict outbound EC2 to only access S3?

I want to restrict the outbound security group from an EC2 instance. The instance only needs to access an S3 bucket. I just learned that S3 uses port HTTPS (443). I could just put that rule in place ...
0
votes
0answers
30 views

Network configuration for Virtual machine based firewall

I have this physical configuration: And I'm planning to install IPFire (or similar firewall : pfSense or Sophos UTM) on a virtual machine on the Active Directory Server to control traffic between ...
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0answers
24 views

Windows Advanced Firewall - Advanced Rules? [duplicate]

my game server is being DDoS attacked (Windows Server 2012). Probably you would say there is nothing I can do but I don't think so because I can use my dedicated server in a normal way, it's just that ...
0
votes
1answer
28 views

How do I use CSF to redirect domain requests to a port?

I have a server setup that uses two different webservers with different subdomains. Right now the servers listen on different ports (80 & 4000) So users don't have to put in :4000 I'd like to ...
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votes
1answer
64 views

How to open Port 443 on External Firewall? [closed]

I've been trying to configure SSL on my server for last 4 days now, with absolutely no success. I've generated a CSR file and uploaded the certificate and configured a Vhost, but nothing seems to ...
1
vote
2answers
32 views

Does Windows Network Load Balancing require any specific ports to be open?

I have two Windows 2012 servers, joined in a Windows Network Load Balancing cluster. I have been trying to find how the NLB heartbeat message is exchanged between those servers (to make sure it will ...
0
votes
1answer
34 views

Loading fail2ban rules to iptables using iptables-persistent

I am using iptables-persistent package to reload my iptables on boot. And I have been thinking should I add the fail2ban rules to the loaded config file? Now I am seeing they are duplicated. This is ...
1
vote
1answer
51 views

Apache problems in performance test with mod_reqtimeout

We have 2 Apache webserver behind a load balancer wich are connected to 2 (JBoss) application servers via mod ajp. To those webservers, mobile devices connect via a REST API. In our performance ...
0
votes
2answers
77 views

How to enable CentOS 7 to connect to an external SMTP? [closed]

I have a web application deployed in a webserver, running on a CentOS 7. This web application sends e-mails through an external SMTP (in-v3.mailjet.com, port 587). How can I enable CentOS to connect ...
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votes
1answer
38 views

Open source firewall as a virtual appliance? [closed]

Is it possible to have an open source firewall which can run as a virtual appliance into a guest VM where all traffic from the other VMs should go through this firewall VM? And it supports also ...
-1
votes
1answer
45 views

Block everything except some ports and specific IP Addresses, server can't do HTTP GET

I can't get this firewall.sh script to work. It currently doesn't allow me to get a file at 'https://index.docker.io/v1/repositories/library/ubuntu/images' so either my DNS is flawed or I am blocking ...
1
vote
0answers
31 views

Hadoop namenode port getting blocked

I have installed 7 VM instances of Ubuntu 14.04 LTS servers. First instance runs the namenode service and all other 6 nodes run datanode service.I think my NameNode is getting crashed or blocked due ...