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

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11
votes
8answers
27k views

Blocking Facebook and Myspace by IP address

I'm having some trouble making a Cisco ASA device block certain social networking sites which have become time sinks in our office. This question is really in two parts: Is there a reliable way to ...
6
votes
5answers
8k views

Disable Windows Server Network Locations

I'm not sure what exactly this feature is called. But in Windows Server 2008, it has the Vista Public/Private/Domain locations. This makes sense for laptops, and none at all for servers. My problem ...
2
votes
13answers
6k views

What free options are available for web content filtering? [closed]

I run the IT Dept at a small high school with about 500 users on the network. We have been using SurfControl for this which has been handy because it backs into MS ActiveDirectory very well. We ...
10
votes
2answers
14k views

Windows Advanced Firewall: What does “Edge Traversal” mean?

this should be a really simple one: In Advanced Windows Firewall on Windows Server 2008+, Properties > Advanced, what does "Edge Traversal" mean? I Googled it, of course, and was unable to come up ...
4
votes
3answers
4k 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 ...
3
votes
1answer
646 views

UFW/IPTables: how to securely allow authenticated git access with github

This is how I setup my iptables with UFW: sudo ufw default deny incoming (deny all incoming) sudo ufw default deny outgoing (deny all outgoing) sudo ufw allow out 53 (accept outgoing DNS traffic, ...
3
votes
1answer
2k views

How can I rate limit SSH connections with iptables?

I'm trying to limit the number of possible SSH connections to my server but it just seems to lock me out every time. I'm not very familiar with iptables but I've been reading up on the rules that I ...
2
votes
2answers
4k views

Should I rate-limit packets with iptables?

I'm using iptables on Ubuntu Server. It's a web server on a VPS. I'd like to know if I should rate-limit packets. If so, what should I rate-limit? And should I do so globally or per IP address? ...
2
votes
2answers
1k views

IPFire firewall under Hyper-V. How to get synthetic devices working?

The latest version of IPFire (v2.7 core 38) uses the linux 2.6.32.15 kernel. This includes Microsoft's Hyper-V synthetic drivers. How do I get them working? When IPFire boots, it loads the hv_vmbus ...
1
vote
4answers
3k views

Linux Firewall + Loadbalancer distribution

Can anyone recommend a Linux specialized distribution (or appliance) which provides both Firewall and Load-balancer? Something similar to IPCop for example, but containing LB as well? Thanks in ...
6
votes
2answers
2k views

Is there a secure way to allow IIS 7 in a DMZ to access a DB server behind the firewall?

Our network admins are adamant that it is insecure for our web servers, which are hosted in the DMZ, to access the DB server behind our firewall. To get round the problem, we access the data via web ...
5
votes
1answer
450 views

Block outgoing connections for certaing uids (root, apache, nobody)

With iptables in CentOS 5 and 6 Linux - how can you please prevent processes running as root, apache or nobody from initiating outgoing connections? On CentOS 5 Linux I've tried putting these lines ...
5
votes
2answers
1k views

Linux fails to interpret ACK, keeps resending SYN+ACK

The following is a wireshark dump of the problem occurring, IP-adresses replaced with 'client' and 'server': 4414.229553 client -> server TCP 62464 > http [SYN] Seq=0 Win=65535 Len=0 MSS=1452 ...
5
votes
4answers
404 views

iptables: change policy or use catch-all rule?

What do you do when setting up iptables: change the default policy (iptables -P INPUT DROP, for example) or add a catch-all rule at the end of the ruleset (iptables -A INPUT DROP)? If you do prefer ...
5
votes
6answers
775 views

Advice a good hardware firewall [closed]

Which firewall would you advice to use to meet following 1Gb line and most anti hacking modules. Price range 10k-15k$. 3 years warranty on site, full support online. About modules, i don't know what ...
3
votes
1answer
566 views

iptables preroute localhost

I would like to forward all incoming traffic from a certain port to another one using iptables. The problem is that prerouting doesn't work for traffic from localhost. This topic suggests a solution: ...
3
votes
2answers
4k views

Why can't I ssh or ping my brand new Amazon EC2 instance?

I just created a free EC2 instance with all the defaults. It says it's running in the AWS Management Console. On the "Instance Actions" menu, I click "Connect". I copy the DNS name provided (looks ...
3
votes
3answers
10k views

Cisco ASA logs “regular translation creation failed for icmp …” for DNS traffic, yet it works

Every few minutes our Cisco ASA 5505 firewall is logging errors that I can't figure out with my limited Cisco experience. Severity Date Time Syslog ID Source IP Destination IP ...
3
votes
8answers
40k 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
votes
11answers
2k views

Which hardware for an entreprise router/firewall/content filter/proxy on a single server [closed]

I have to set up a "secure" network for my boss. For now, I have a ADSL router linked to a switch. All users are connected to this switch. Security is obviously bad. I want to put a server between the ...
2
votes
4answers
831 views

Linux router and firewall with IP accounting

I'm working on a project to replace my organisation's aging Slackware gateway/router/firewall machine, which will have several hundred users behind it. Previously we used rc.firewall but we are now ...
2
votes
4answers
563 views

How to browse to a webserver which is reachable through the SSH port only

I have a server at work which is behind a firewall (the company's firewall) so it is reachable only thrugh port 22 (SSH). I'm able to connect to the server with putty without problems. Also, that ...
1
vote
3answers
1k views

Blocking IP behind a load balancer

Is there any way to block IP address of an intruder (or any IP), when our server is behind a Load balancer. For example if my servers are behind ELB (Amazon ELB) or Rackspace Load balancer, i am ...
1
vote
2answers
3k views

pfsense setting up as transparent firewall - dhcp issue

I followed the directions to set up pfsense in bridged / transparent mode per the instructions at http://doc.pfsense.org/index.php/Configuring_pfSense However I can not get a dhcp address from my ...
1
vote
3answers
280 views

Network Question

I have a question about whether something is 'possible' by default or requires additional setup. Lets say I have two systems behind a firewall and they are in the same domain and subnet. System 1 has ...
1
vote
1answer
2k views

CSF firewal - how does csf.allow work?

In my csf.allow file I have (something like): 98.765.43.21 tcp:in:d=20:s=12.345.67.89 tcp:in:d=21:s=12.345.67.89 Am I right in thinking that this will 1) always allow any service for 98.765.43.21 ...
1
vote
1answer
1k views

How to stop OpenEsb Glassfish Admin console from opening connection to glassfishesb.org

I have a Glassfish v2.1 app server (OpenEsb distribution) running behind a very restrictive firewall. Some times a bottom frame will appear, trying to connect to this address: ...
0
votes
2answers
594 views

Linux iptables allow some ports

We have a Linux server (CentOS 6.3), where all ports seem to be accessible from inside (when tried from the server), but only SSH is accessible from outside. I would like to allow some other ports, ...
0
votes
1answer
265 views

Can these IPv4 and IPv6 firewall rules be hardened any further? [closed]

I am running Ubuntu 10.04. Here are the IPv4 firewall rules that I've been using now for a few months: *filter #Allow all loopback (lo0) traffic and drop all traffic to 127/8 #that doesn't use lo0 ...
0
votes
1answer
601 views

ConfigServer Security and Firewall — after setup, how much daily management required?

I'm looking at using ConfigServer Security and Firewall (CSF; iptables-based). After I configure it properly, how much daily ongoing management is required of me to keep my server secure? Am I going ...
0
votes
2answers
312 views

Web server hardware firewall recommendations [closed]

I'm looking for a specific hardware firewall model solutions that best accommodate the following concerns [Cisco models are best, because our colo can get good deals on them reconditioned]: There ...
0
votes
1answer
847 views

How to relax firewall for UDP connections/ports for a specific IP address?

My server is Red Hat Enterprise Linux Server release 5. iptables version is v1.3.5. I want to allow all UDP connections / port for the IP address 192.168.0.200. This IP address is configured in my ...
0
votes
1answer
2k views

Multiple interface NAT routing

I have multiple internet connections from different ISPs and I need to route certain traffic over a particular ISP link. I am using Debian for this. The setup is as follows; eth0 (IP address is ...
-1
votes
3answers
281 views

iptables — am I doing this right?

UPDATE Boy am I glad I asked. OK, I'll try again and post another question. I'd like to set up a CentOS 5.3 host to allow only ping, ssh, httpd, and SSL connections. After reading a tutorial and ...
6
votes
3answers
287 views

Is there already a recommended IPv6 Firewall setup?

I'd like to switch from private-IPv4-subnet-behind-NAT to IPv6, but of course I have no intention of exposing my users' workstations "unprotected" to the net. Some obvious points up-front: Allow ...
5
votes
9answers
3k views

Block users from Social networking websites while firewall is down

We currently have a SonicWall firewall, which does a pretty good job a blocking Social networking websites like Facebook and Bebo. The problem we are having is that sometimes we need to temporarily ...
4
votes
3answers
2k views

Comparison of Firewall, Intrusion Prevention, Detection and Antivirus Technologies in Organizational Network Architecture

in these days i'm reading about intrusion prevention/detection systems.When reading i really confused in some points. First, the firewall and antivirus technologies are known terms for years, however ...
4
votes
2answers
5k views

Should I use TCP or UDP to run a web server

I have just installed Apache web server on my computer. I have managed to use it locally (I can open index.php from my computer using my web browser). But I would like to make my web site available ...
3
votes
3answers
4k views

Enabling http access on port 80 for centos 6.3 from console

Have a centos 6.3 box running on Parallels and I'm trying to open port 80 to be accesible from outside tried the gui solution from this post and it works, but I need to get it done from a script. ...
3
votes
4answers
578 views

Is it alright to turn off firewall in a LAN using Group Policy?

Is it a good idea or common practice to completely turn off windows firewall in an AD domain using Group Policy? At this time, even the servers' firewall are turned off. The only device not affected ...
3
votes
2answers
373 views

Is my linux firewall secure?

I am newbie to linux firewalls and trying to setup my systems firewall for a public facing computer. Here are my requirements: Ports 80 and 22 should be open for HTTP requests and SSH logins Since ...
3
votes
5answers
2k views

Apache DDoS Protection in router (pFsense) [duplicate]

I'm soon going to change my infrastructure when I buy a new server. I'm going to replace my D-Link DIR-655 router with an pFsense router (and probably use the 655 as an AP) using my old server ...
3
votes
3answers
3k views

How long does it take for an iptables rule to apply?

How long does it take for an iptables rule to apply? I use a script with the code below in an attempt to block hosts, but they don't appear to take immediately. Is there some delay, is iptables not ...
3
votes
5answers
3k views

connect to ssh server thru 80 via HTTP proxy?

Please help: I want to connect to my ssh server at home However, I'm behind a corporate (CORP) firewall, which blocks almost all ports (443, 22, 23 etc). But it seems that 80 is not blocked, coz I ...
3
votes
7answers
3k 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
votes
7answers
836 views

Is Windows 2003 Firewall appropriate for a web server?

I currently have a colocated server being protected by a hardware firewall, however this firewall is old and I want to replace it. I was wondering if the built-in Firewall software for Windows 2003 ...
3
votes
1answer
681 views

Will you allow NetBIOS into your DMZ?

Is it secure for a firewall to allow NetBIOS connections from the internal network to the DMZ? If not secure, what are the risks? If secure, what is the FUD about and what are the counterarguments? ...
2
votes
2answers
1k views

Reduce firewall rules by half - one iptables rule for tcp and udp

I have a number of iptables rules on my firewall that look like this: iptables -A zone_lan_forward -p tcp -d 1.2.3.0/24 -j ACCEPT iptables -A zone_lan_forward -p udp -d 1.2.3.0/24 -j ACCEPT Is ...
2
votes
2answers
454 views

Virtualizing Firewalls/UTM

So Sophos UTM (Astaro Gateway UTM) can be virtualized in Hyper-V, VMWare, vSphere etc. Now I'm new to virtualization, so am wondering how the networking would be configured in this situation. ...
2
votes
2answers
2k views

Ports used for Lync Edge server

I have Lync 2010 Standard deployed in my environment, along with an edge server. On my firewall I have NAT'd the public address(s) to the server. Right now I have all the ports opened for these ...