Concerned with software or hardware firewalls

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1answer
485 views

Windows Firewall netsh equivalent of iptables u32 module

I have looked everywhere and I can't seem to find a netsh equivalent of the u32 module for iptables. I want to create a rule to Drop a packet that starts with a specific set of bytes. Similar to: # ...
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2answers
80 views

How does Network Address Translation (NAT) increase firewall effectiveness

Truth or bald-faced lie: the cheap $50 router you can pick up at your local electronics store for your home broadband Internet connection is actually a pretty effective firewall. Why or why not? How ...
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5answers
61 views

Firewall rules by URL

is there a solution to create FW rules by URL instead of IP for inbound traffic? For example a.example.com and b.example.com are the same IP on the DNS, but they are different sites, is there a ...
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1answer
32 views

ESET detected incoming connection to Rundll32

My ESET Smart Security 7 detected incoming connection from an external computer, since Rundll32 can be run by any programs on my computer and I don't know which program is doing this, so I am ...
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2answers
62 views

Is it not safe to open MySQL's port to the internet?

The consensus on this Server Fault question seems to be that opening port 3306 for MySQL is more dangerous than using an SSH tunnel to access MySQL. I would think that with strong credentials you ...
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0answers
50 views

iptables raw table

I'm trying to collect iptables common shield rules, here is my current list: echo "-Check for All flags enabled&Drop." iptables -I INPUT -p tcp --tcp-flags ALL ALL -j DROP echo ...
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1answer
97 views

Is it safe to disable connection tracking in iptables?

While reading about NOTRACK target of raw table in iptables, I encountered an article suggesting that for certain traffic you could (or even should) disable connection tracking. The two examples were: ...
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0answers
20 views

How to use the Suricata IDS to monitor the entire network? [migrated]

I have the following 3 PCs connected to a router via Ethernet: PC1 – 192.168.1.101 (Linux Ubuntu) PC2 – 192.168.1.100 (Windows) PC3 – 192.168.1.1 (Windows) All PCs can ping each other. PC1 has ...
1
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1answer
239 views

VPN Client - Addtional Security Layer or a Useless Feature

I have a corporate web portal which is used for staff collaboration including a web-based mail interface connected to MySQL Database, corporate calendar, file storage, customer contacts data with ...
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1answer
96 views

ASA5505 DMZ issue

I have ASA5505 , connected to the WAN on port 0 (called Vlan2), and connected to my development LAN on port 7 (Called Vlan1). I want to add DMZ, and I connected switch and servers to port 3, and ...
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2answers
1k views

Reverse shell connections

Why are reverse shell connections so popular in the event of a successful intrusion? Many "hacking" videos show this and it is often seen in practice. Would not most servers restrict outgoing ...
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0answers
29 views

Firewall init script [migrated]

On Debian, what is the best way to start an iptables firewall script : /etc/init.d/firewall_script.sh in /etc/network/interfaces, add post-up /etc/network/if-up.d/firewall_script.sh Do you check ...
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1answer
198 views

How to configure Suricata to not interfere with virtual machine

I'm currently planning on setting up Suricata as a firewall on my laptop. I'm wondering however if it's possible to set Suricata to not interfere with traffic to and from specific virtual machines ...
0
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1answer
92 views

Is a firewall an access control list?

I want to know if a firewall is considered an access control list (ACL). I know there are other types of ACLs, but am specifically interested in knowing if a firewall is an ACL. Edit: It appears ...
0
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1answer
96 views

Firewall hole punching [closed]

I'm interested in doing my thesis on Firewall hole punching. Hole Punching: A way to exploit NAT to open a connection TCP or UDP between a Client and a Server. What I'm looking for is a reason this ...
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2answers
73 views

How to block network scans with pfsense?

I am using pfsense as firewall, and I would like to know how I can stop network scans from enumerating open services and ports. Thanks
4
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1answer
66 views

DMZ Firewall settings

I am involved in project where I have to install a new server for a new application to a preexisting production network. The new server shall sit in the DMZ and two controllers will sit on the ...
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2answers
106 views

Securing a Windows PC

Currently I have an "Antivirus" and Anti Malware software installed. In addition I closed all remote assistance and unused port rules on my firewall. I'd really like to get a complete as possible ...
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5answers
6k views

Are two firewalls better than one?

Let's say that our first firewall have some vulnerability and malicious person is able to exploit it. If there's second firewall after it, she should be able to stop the attack, right? Also what will ...
0
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1answer
90 views

Foreign MRT.exe?

I was managing my firewall using AVG and I noticed this was allowed: I have north american locale, and sometimes Japanese locality(?), and that is not Japanese. It is getting through my firewall, ...
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2answers
189 views

Could a router protect our network or need we use an hardware firewall?

I am at a small firm (12 PC on the internal network). We use this network architecture now: Internet(Modem) --> Router --> Firewall --> Switch -- > Internal Network (clients PCs) ...
0
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0answers
22 views

Is it possible to covertly tunnel data using L3DSR? (or any other TCP or IP layer hack)

I asked this question on ServerFault regarding how a Netscaler embeds low level data in a TCP packet, round-trips it, and then uses that data to loadbalance the user. Similar to DNS Tunneling, I ...
30
votes
7answers
18k views

Why do people tell me not to use VLANs for security?

I have a network, where a have a couple of VLANS. There is a firewall between the 2 VLANs. I am using HP Procurve switches and have made sure that switch-to-switch links accept tagged frames only and ...
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2answers
12k views

What advantages and disadvantages do Palo Alto firewalls have, compared to others in the market

I am about to start an evaluation process for firewalls. I have experience with Checkpoint and Juniper, but I don't have any information on Palo Alto networks, other than their marketing stuff. So I ...
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3answers
1k views

How to block the websites on client machines

In our office we are blocking sites like Facebook, Twitter etc.The problem is that some of the users bypass our proxy and firewalls through external proxy sites like www.youhide.com or ...
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2answers
127 views

Do I need a hardware firewall even if I have Internet security software?

I have Kaspersky Internet Security 2010 installed on my Win7 computer. I assume it gives me enough protection for a software firewall(port security,tracking tcp,udp traffic etc.) Do I still need a ...
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2answers
145 views

VPN blocked ports problem

I use VPN quite often in public places where I don't want anyone to read my web traffic. However, some public places have firewalls that block ports required to establish a VPN connection (I usually ...
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4answers
181 views

Find out what Linux software is trying to phone home

I have seen some suspicious outbound communications blocked on my VPS, which hosts a small experimental Web site, and want to find out which application is making the attempt. The server is running ...
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2answers
111 views

How to prevent attacks to server

I have 3 CentOS server configured for my applications. Recently I recognized that there is so many attacks to my servers. I have so many logs about attempt to login to my servers using sshd from ...
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2answers
53 views

Intrusion detection system and firewalling

I have a website and hosted some data and MySQL files on it. Is it possible for me to install an intrusion detection system on it, or can IDSs only be installed on my internal network where I have a ...
1
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5answers
118 views

Do firewalls always run in userspace?

There are many Firewall solutions for the world on different operating systems: iptables, pf, ipfw. My question is: Does the firewalls run in kernel-space or all of them runs in user-space? (in ...
42
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2answers
19k views

Is it a bad idea for a firewall to block ICMP?

This question was inspired by this answer which states in part: The generic firewall manifest file finishes off by dropping everything I didn't otherwise allow (besides ICMP. Don't turn off ICMP). ...
2
votes
1answer
224 views

How can the Google web crawler bypass portals?

This is a situation that I have encountered on a number of occasions. I will conduct a web search in Google, a link to a file (.pdf for example) will take you to that file on the server. It opens up ...
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1answer
4k views

How to block all access to Akami deploy servers and Apple push servers?

I no longer blindly trust the numerous connections that occur at night and during the day that always go to "content" and "push" servers like: a23-33-37-54.deploy.akamaitechnologies.com ...
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0answers
53 views

How should I configure my Tor-dedicated firewall for optimum security?

I'm setting up a Tor-based isolating proxy using the 'Anonymizing Middlebox' iptables rules specified here: https://trac.torproject.org/projects/tor/wiki/doc/TransparentProxy i.e. iptables -t nat ...
1
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3answers
334 views

Best practice for accessing management port of firewall

I'm in the process of setting up a bunch of servers at the other end of the world (well, 8 hours travel time) in a co-location place. The servers and firewall all have a remote management port (KVM, ...
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0answers
28 views

Carry out an attack on port 80 while only 20 is allowed [duplicate]

There is a question bugging me a after reading on network security. Theoretical situation: there is a packet-filtering firewal which only accepts tcp / ip communication with destination port 22 on a ...
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7answers
3k views

Port Knocking is it a good idea?

Normally for a server I like to lock down SSH and other non-public service to only be accessible by certain IP addresses. However this is not always practical if the business doesn’t have static IP ...
1
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2answers
142 views

What security does an ISP provide for its customers?

I've heard that ISPs provide some kind of protection; using NAT and firewalls, to prevent hackers from using tools such as nmap to attack customers from over the Internet. What other technologies are ...
1
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4answers
18k views

How to effectivily block torrents on my network?

Hie, As per my network policy, we have to block all torrent traffic from network. To do this, I used to block all ports above 1024 on my firewall/proxy devices. But due to this, many other ...
0
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1answer
45 views

If I port scan a server on the outside of a firewall will this also tell me the ports the firewall is blocking?

Theoretically I was thinking a firewall inspects the TCP header and looks at the destination port and discards/forwards based on its firewall rules. So could I port scan an external server to the ...
1
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4answers
96 views

Is it possible to block specific users that connect to the internet behind of same gateway with NAT?

Assume there are two internet users (A and B) that connect to the internet from the same gateway by using NAT. That means they use same IP address while passing through our firewall. Now assume we ...
0
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0answers
68 views

OpenVPN and firewall configuration in LuCI

I'm trying to find the best (most secure) configuration for the firewall in OpenWRT. I'm using LuCi to configure all the stuff. I have successfully created a VPN (OpenVPN). It is supposed the best ...
0
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1answer
360 views

how to bypass windows xp firewall with nmap

I'm scanning a Windows XP in a virtualized environment. I use all of needed arguments to bypass its firewall but it doesn't answer: nmap -e eth0 -Pn --data-length 5 --badsum -g 80 -S 192.168.1.103 -f ...
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2answers
46 views

Does it make sense to log accepted traffic on firewall?

Assuming a firewall is properly setup, only allowing determined traffic and dropping everything else, what relevant information (if any) could I get from the log of the accepted rules? From the ...
0
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1answer
114 views

Finding the firewall port that filters internet traffic [closed]

In my office, we have static IP's for each system. All the internet traffic from our systems are filtered with a Fortiguard firewall. Is it the default gateway where the firewall is installed? How can ...
8
votes
3answers
4k views

Proxy vs. Firewall

I understand that very simply put a proxy is a sort of 'man in the middle' allowing/denying access to certain services/resources. Strictly in terms of security (I mean here privacy, parental control ...
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3answers
4k views

What, specifically, does the Windows Firewall do?

My understanding of the situation is that, when the Windows firewall is off, every port on the computer (all 65535 of them) is fully open. This means that any application running on the computer can ...
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2answers
243 views

Blocking incoming traffic from privileged port (< 1024) to mitigate DNS DDos Amplification attacks

Hope someone can clarify. As I understand, in a DNS DDos Amplification attacks Multiple DNS queries are sent to a vulnerable name server with the source IP spoofed to that of the target server. The ...
1
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1answer
56 views

Allow loopback in Iptables?

I'm trying to write Iptables rules for a small web server. Almost every source I've encountered recommends to allow loopback access to the web server, but doesn't explain why this is necessary. ...