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

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recommend firewall options for a dedicated server

I'm looking for recommendations on firewalls for a dedicated server that will be hosting a few websites of average traffic (5000 uniques monthly). the hosting company has port and full hardware ...
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1answer
10k views

Which firewall ports do I need to open in order for a domain trust to work?

I have two Active Directory domains in two different forests; each domain has two DCs (all of them Windows Server 2008 R2). The domains are also in different networks, with a firewall connecting them. ...
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3answers
895 views

Can our firewall detect traffic sniffing inside the network?

We use Cisco ASA's firewall and NAT functions in our network (200 computers). Is there any possibility to configure Cisco ASA to detect traffic sniffering (for example wireshark) and network ...
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3answers
6k views

Denying ICMP type 3 code 4 traffic - good or bad?

Investigating a slow VPN connection (Cisco ASA IPSec) to a remote office, I noticed on our firewall a lot of access rule matches: Denied ICMP type=3, code=4 from *ip_address* on interface outside I ...
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1answer
4k views

DMZ Setup with two firewalls - Traffic from DMZ to LAN and LAN to DMZ

I am setting up a network with machines that need to be accessible from the internet. I'm planning on putting these in a DMZ. Some of the machines in the DMZ need access to machines on the private ...
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1answer
221 views

Can tcpdump tell accessed port numbers?

I have a server with two NICs, and I would like to only have those ports open on eth1 that are being used. Question How do I get tcpdump to tell me the port numbers that is being accessed on eth1?
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3answers
312 views

node.js 0.4.0 not serving files to external IPs

When I run the following script http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(80, ...
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4answers
2k views

iptables, blocking large numbers of IP Addresses

I'm looking to block IP addresses in a relatively automated fashion if they look to be 'screen scraping' content from websites that we host. In the past this was achieved by some ingenious perl ...
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3answers
3k views

MSMQ Firewall Ports

I'd like to know what ports need to be opened on a firewall in order to allow public read access to an MSMQ private queue. I'm aware that Microsoft publishes a list of ports here: ...
4
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1answer
415 views

Linux NFLOG - documentation, configuration from C

Several different places (e.g. http://wiki.wireshark.org/CaptureSetup/NFLOG) recommend using Linux's "NFLOG" firewall module to capture packets generated by a particular UID, like this: # iptables -A ...
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3answers
907 views

connected to Centos openvpn but no outside internet access

I am using Windows 7 to connect to a VPS server running CentOS 6.4 First off, I have read every single post and just cant find the solution to my problem I configured my VPN server with openvpn, and ...
4
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2answers
176 views

ipv6 multiple addresses and firewall on remote machine

I have an ubuntu server (serverA) which has a couple of IPv6 addresses. One of these is based on it's MAC address, and is known to the network, the other one I presume ubuntu created as a 'private' ...
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2answers
2k views

ufw blocking apt and dns

I installed ufw on my Debian system like the following: # aptitude install ufw # ufw limit 22 # ufw allow 80 # ufw allow 443 # ufw enable # ufw status verbose Status: active Logging: on (low) ...
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2answers
2k views

Secure NAT setup with iptables

I have a Debian running device that needs to act as an internet-gateway. On top of that I want to provide a firewall that not only blocks inbound traffic, but also outbound traffic. And I figured ...
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2answers
4k views

How can I track down what part of pfsense is blocking website access?

I've got a PFSense firewall/gateway on our network. Everything works great except for the fact that I cannot access one specific website. Pfsense is running the following packages Country Block ...
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2answers
515 views

Iptables - Block https response only

I'm quite new to Linux and using iptables. Here is what I am trying to accomplish: I have an ASP.net client that talks with a web service hosted through web-logic on linux. The communication is over ...
4
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1answer
461 views

Block outgoing LOIC attacks in a network

I am admin of a small network. Users in our network have access to internet through a squid NAT server. Recently, we have detected that some users are using LOIC to attack servers on the internet. ...
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5answers
237 views

What are the 'gotcha's' a software developer needs to look out for if tasked with setting up a production ready server?

As a software developer I am very used to installing my typical stack (java, mysql and tomcat/apache) on my development machine. But setting up and securing a production machine is not something I ...
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3answers
21k views

How can I open a port on my EC2 instance?

I'm working for a client here who has set up an EC2 instance for me to configure. I've installed the software asked for, now all I need to do is open up some ports. I'm currently SSH'd into the ...
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3answers
184 views

linux Firewall question

I have few generic questions about firewalls and I thought the community up here could help me out. 1) So I recently installed Ubuntu server barebones. I checked for open ports, none were open which ...
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2answers
869 views

iptables and blocking potentially impossible traffic

I am working on some iptables firewall rules and have seen many examples that suggest the importance of blocking potentially impossible traffic from non-routable IP address spaces. This would include ...
4
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4answers
543 views

Why on linux machines, any packets do not pass except icmp, but correctly pass on windows

There is a cluster on proxmox. In a cluster have vm - configured router (pfsense). In the our net have Windows and Linux machines. There is the problem: Windows-machines have access to the internet, ...
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1answer
104 views

Managing security and firewalls in complex, distributed applications

We have a distributed application composed of several different components. For example, we have Python app servers, PostgreSQL DB servers, Redis servers, Memcached, etc. Some of these services are ...
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1answer
623 views

Firewall ACL management tool

Is there any Firewall ACL management tool which can generate set of ACLs for all my network, including switches, checkpoint, cisco routers, windows, linux etc? I think such tool would make sense as ...
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1answer
98 views

Seeing strange IPv6 requests being dropped in our firewall

I'm seeing the following IPv6 addresses having requests dropped by our firewall. It doesn't seem to be anything too malicious, but there seems to be a strange pattern to them: ...
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1answer
161 views

Access, Permissions, and Security for 3rd party developers

Our Marketing department wants to start hiring an outside company to assist in the development and maintenance of our marketing website. The website right now is on FreeBSD (using apache), but with ...
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1answer
1k views

Cannot loopback to localhost php gateway causing nginx to timeout while setting up firewall with ufw

I'm setting up ufw for the first time. Using Ubuntu 10.04 LTS on an OpenVZ VPN and have the following rules: sudo ufw allow 22/tcp sudo ufw allow 25/tcp sudo ufw allow 53 sudo ufw allow 80 sudo ufw ...
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3answers
5k views

How to configure remote access to multiple subnets behind a SonicWALL NSA 2400

I have a client that uses a SonicWALL NSA 2400 as their firewall. I need to setup a second LAN subnet for a handful of PC. Management has decided that there should be a second subnet even though ...
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3answers
2k views

OWA not working from outside the network

I have an Exchange server behind an ISA 2004 server and from inside the network, it's possible to access Outlook Web Access. I have published the server but from outside the network I'm not even ...
4
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1answer
94 views

firewall and private cloud

We have a private bay in which we built a private cloud with vmware vSphere. We received directly the web trafic on a firewall VM and then we forward the trafic to the appropriate VMs. We are worry ...
4
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1answer
109 views

Ban an IP when the server received an amount of data from it

What I need : There are many result for adding a drop rules by an amount of request per laps of time, but I need to drop by received byte count from a particular address over a period of time. ...
4
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2answers
121 views

iptables - allow connections to a port only for IP addresses with established state on a different port

I want to allow connections on port x for IP addresses that have a 'established' state on port y. Is this doable by just using iptables?
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1answer
399 views

pf slows traffic extremely down

I am running a web and mail server on FreeBSD 9.1. The system is installed on a KVM vServer. Everything works fine - until I enable pf(4). My weblog becomes unconscionably slow. So does all the other ...
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3answers
5k views

automatically block IP address after many failed login attempts

I am receiving a lot of failed login attempts (1 per sec) on a Windows 2008 server, I have already set local security policy to automatically lock an account after too many login attempts, but is ...
4
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3answers
5k views

pfsense log file retention

We have a pfSense firewall in our datacentre. By default, pfSense is only storing 500K of firewall filter logs, which is only a few hours for us. How can I increase this? pfSense uses clog rather ...
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3answers
8k views

psexec Couldn't access \\IP/computername The system cannot find the path specified

Tried psexec \\ip.add.re.ss -accepteula -u local_admin -p cmd.exe psexec \\computername -accepteula -u local_admin -p cmd.exe psexec \\computername.fdqn -accepteula -u local_admin -p cmd.exe where ...
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7answers
25k views

problem with passive FTP behind cisco asa firewall

i've problems connecting to an ftp-server behind a cisco asa firewall using passive mode. ftp works using active and "extended passive" mode, however: when i turn off "extended passive" (epsv in ftp ...
4
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1answer
525 views

Why does Terminal Services open WMI, RPC, and NB ports in the firewall?

After adding the Remote Desktop Session Host roll to a server the following firewall rules get created and are enabled by default. Name Group Profile ...
4
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1answer
505 views

ipset - recommended method to reload rules after reboot

Am implementing ipset on some Fedora 16 systems. Since ipset rules run in memory and are lost on reboot planning to use a crontab @reboot script to reload the rules and send an email to administrator ...
4
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1answer
17k views

How do I route between interfaces in PFsense?

I have a PFsense router which divides a single WAN connection into three NAT networks on three interfaces: LAN, OPT1 and OPT2. This allows me to segregate my network so that computers on the OPT1 and ...
4
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1answer
3k views

Single m0n0wall - Two LAN Subnets - How To Setup

I have two LAN subnets that I need to link together they are 192.168.4.0/24 and 192.168.5.0/24 There is a m0n0wall running on 192.168.4.1. It's LAN connection goes out to our network switch, and it's ...
4
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2answers
3k views

Correctly setting up UFW on Ubuntu Server 10 LTS which has Nginx, FastCGI and MySQL?

I'm wanting to get my firewall on my new webserver to be as secure as it needs to be. After I did research for iptables, I came across UFW (Uncomplicated FireWall). This looks like a better way for me ...
4
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2answers
250 views

Windows XP firewall behavior mysteriously changed

Recently (July 13, 2010) I had a firewall rule that started blocking traffic that had previously been allowed. I have an FTP server running on a non-standard port serving files to the LAN. I had ...
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9answers
5k views

Why am I Unable to ping port 443 on Ubuntu?

I have opened port 443 through iptables: pkts bytes target prot opt in out source destination 45 2428 ACCEPT all -- lo * 0.0.0.0/0 0.0.0.0/0 6 1009 ACCEPT tcp -- * * 0.0.0.0/0 ...
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7answers
3k views

Stealthed vs Closed Port

I was reading a website about the difference between stealthed and closed ports. http://www.grc.com/faq-shieldsup.htm A closed port will echo a packet if closed. However, a stealthed port will not ...
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7answers
2k views

Good linux firewall? [closed]

I am looking for a good firewall for debian 5 which is a web server. Are there any good options apart from iptables? Thanks
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7answers
4k views

4 NICs or 4-port NIC?

I want to setup a firewall handling two ISP connections and two routers. For that I am planning to use an old Pentium 3 machine. Now, should I use four network interface cards or a 4-port NIC? Do ...
3
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9answers
21k views

“account currently disabled” when accessing share, even before logging in

When I try to access a share folder, say \\share-folder, I get the following error message: logon failure: account currently disabled This seems strange to me, since there is no 'account' to be ...
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8answers
41k views

How to enable sshd on Fedora 11?

I have just installed Fedora 11 on my desktop system and would like to have sshd work. These are the steps I have done: Enabled sshd as a trusted service using system-config-firewall Restarted sshd ...
3
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5answers
215 views

Good firewall for Vista? [closed]

I just bought my first laptop. It runs Vista, and I need a software firewall to protect both its Ethernet and wifi connections. I use the free Comodo Personal Firewall on my desktop, but I read that ...