Concerned with software or hardware firewalls

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11
votes
7answers
5k views

What security implications are there for allowing outbound SSH traffic?

My school currently blocks outbound SSH traffic. Users inside the network cannot use Port 22, and attempting to make an SSH connection over another port is also blocked. (I'm assuming the firewall ...
2
votes
5answers
666 views

How do a firewall's rules for individual programs work?

I kind of know that how a firewall's rules for IP/port work, but I have no idea how a firewall deals with individual programs. In other words, how does the firewall know a program wants to access the ...
2
votes
3answers
2k views

Use a Common Firewall for two Different Subnets

I want to implement a security scheme in a new network configuration. There are two buildings for the client: Office Building 1 (OB1) with address 10.0.0.0 / 255.255.255.0, Gateway 10.0.0.1 ( ...
5
votes
2answers
20k 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 ...
1
vote
4answers
8k views

Ignoring broadcasts to 10.0.0.255 using iptables

I'm trying to drop logging packets that are destined for 10.0.0.255 by using the following rules: $IPTABLES -A OUTPUT -d 10.0.0.255 -j DROP $IPTABLES -A FORWARD -d 10.0.0.255 -j DROP It doesn'...
6
votes
2answers
15k views

What is best practice for separation of trusted zones from a DMZ with a single firewall?

At our organization we have a single firewall sitting between our internal zones and the public internet. Currently all of our trusted zones are defined as different vlans on a layer 3 switch plugged ...
4
votes
1answer
355 views

Placing a firewall—without creating a new subnetwork

I have a couple of networks that have multiple IP addresses, and where I have absolutely no choice as to the equipment used for the network's edge router (the device that connects both to the LAN and ...
3
votes
2answers
310 views

Can ipopts be used to circumvent a pf or iptables firewall source IP based blocking?

Can one use ipopts, and in particular IP source routing, to circumvent source-based blocking in pf or iptables? For example, with OpenBSD's pf: block in all # default deny block out all pass in on ...
14
votes
4answers
30k views

Tips for a secure iptables config to defend from attacks. (client side!)

Own examples: ############### # KERNEL PARAMETER CONFIGURATION # PREVENT YOU SYSTEM FROM ANSWERING ICMP ECHO REQUESTS echo 1 > /proc/sys/net/ipv4/icmp_echo_ignore_all # DROP ICMP ECHO-REQUEST ...
5
votes
2answers
3k views

incoming packets in server

I have enabled iptables logging for packets coming from the outside -A INPUT ! -s 192.168.218.0/24 -j LOG Now i am seeing lots of incoming packets from unknown addresses Jun 5 14:54:56 localhost ...
7
votes
6answers
323 views

Why shouldn't I run other applications on a Firewall?

If I want to use Ubuntu 11.04 as a Firewall in SOHO environment, then I just can't figure out what is the bad thing about installing GUI on it (e.g.: XFCE)? The only opened port to the world (wan ...
1
vote
2answers
607 views

Is the level of traffic normal against my blocked ports?

I was recommended by my brother to direct the question here about the level of traffic I get against several of my blocked ports. I run pfsense 1.2.3, router in bridge. Behind pfsense I have: 1x ...
2
votes
2answers
4k views

IPTables default security rules for a gateway/router?

On a router such as dd-wrt or tomato, what would be some default iptables rules? I am asking for rules on a router/gateway - For example; blocking SYN flood attacks, or XMAS attacks. The basic ...
5
votes
2answers
3k views

Firewall Configuration Audits

I'm looking to perform policy audits against firewall configurations and/or rulesets. This should be performed independently of any configuration management systems, ideally by operating off the ...
5
votes
2answers
904 views

What are the risks associated with relying on IPSec IP Filtering?

When using Windows IPSec for IP filtering whenever a filter is added you need to have a "mirror" rule (by checking the "Mirrored. Match packets..." tickbox). Because IPSec Filtering is not stateful, ...
6
votes
2answers
4k views

Getting self-signed SSL certificates for all https connections made from some premises

Context: I'm currently working as an expat for my company in a country where the Internet is notably untrustworthy. It made the headlines a few months ago for stealing facebook, twitter and gmail ...
5
votes
4answers
2k views

what is a good public available iptables script for ddos mitigation?

what is a good public available iptables script for ddos mitigation?
6
votes
5answers
1k views

Firewall demo - iptables

I have to make a demonstration about firewalls in my class as a student(university). It should be implemented using iptables on Linux. I am reading all the theories around them but I can't figure out ...
19
votes
2answers
6k views

Reject IP packets with an ICMP error, or just drop them?

Consider an internet-facing host (the outer firewall). What should be done with undesired traffic: just drop it, or send back an ICMP error such as port unreachable? (In Linux terms: iptables -P DROP ...
19
votes
5answers
11k views

Do you detect/react to DNS tunnelling?

I've just seen a talk about tunnelling TCP/IP over DNS requests, because port 53 UDP is usually open and unfiltered. What techniques exist to detect and block such tunnels, and have you ever seen that ...
6
votes
4answers
545 views

What kind of IT security applications do you guys run on your laptop/desktop? [closed]

I know a lot of people run different security applications on their laptops/desktops. I use Little Snitch on my Macbook Pro. I like to know where my applications are sending data and where I am ...
6
votes
3answers
490 views

When you make a revision of rules on a firewall, how do you add credibility/customer satisfaction to your final consideration?

When, for a vulnerability assessment, you need to report the security consideration about a firewall's configuration rule-set, after the audit on the rule-set you make a report about security concerns ...
4
votes
3answers
5k views

How do I configure nmap to verify my firewall is performing stateful packet inspection?

As part of a compliance audit, I need to run a routine scan that verifies that our firewalls are performing stateful packet inspection on incoming packets. I have a dedicated server outside our ...
4
votes
1answer
1k views

Firewall rules to block unwanted protocols on given ports

Does somebody has an idea, that what kind of iptables/pf rule must i use to achieve this?: i only want to allow these connections [on the output chain]: on port 53 output only allow udp - dns on ...
10
votes
4answers
1k views

Software vs Hardware Firewalls

I read an article (can't find link) recently that advocated dumping software firewalls if you had a hardware firewall. I was just curious as to the take on Firewalls in general for a small-medium ...
2
votes
2answers
477 views

What compliance framework is appropriate for firewalls

As a more corpose vulnerability assessment and penetration test, one step of our activity is to review from a security perspective the policy of some firewall. In our society we have a deep ...
6
votes
7answers
9k views

What tools exist to manage large scale firewall rulesets?

For an enterprise firewall you may have over 50 thousand rules. With typical errors in firewall rules including things like mistyped network masks you couldn't hope to manually review the release. So ...
3
votes
2answers
10k views

Disabling windows firewall remotely

i use metasploit for pentesting windows 2003 sp2 server but when windows firewall is on i am not able to perform pentest successfully is there any way to disable firewall remotly?
19
votes
5answers
3k views

To firewall or not to firewall?

There's recently been some discussion (to be generous) about the pros and cons of having a firewall deployed in front of servers. The con mainly being that it's a point of failure in case of a DDoS. ...
7
votes
4answers
4k views

Security Services on Edge Router vs. Standard Firewall

If I can run a site to site VPN, NAT & Reflexive ACLs on a edge router (plus normal routing functions), what would be the use of running a stock firewall behind it? For instance, Core Switch --> ...
10
votes
4answers
2k views

What firewall settings on a Macintosh are the most restrictive, while still permitting casual internet use?

I don't want this to be subjective, so I'll try to make the requirements as clear as possible. On a Mac with Snow Leopard, how can I set up the firewall rulesets that allow ONLY: Using the internet ...
3
votes
1answer
1k views

I'm using a Cisco ASA as a VPN endpoint. Where do the VPN clients get firewalled?

(Is this too application specific? It seems like a reasonable question that would be useful to other people...) So, I've got this ASA in front of a network that I didn't set up. It's been ...
44
votes
10answers
53k 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 ...
4
votes
2answers
2k views

Cisco ASA Security Contexts: Any Real World Installs?

We are looking at deploying a Cisco ASA 5520-I am looking at the security contexts feature, and was wondering if anyone has deployed their ASA in this way, and how it is working out for them. Have ...
8
votes
2answers
364 views

What is secure enough for web applications?

we intend to build a network in a small health center with No Internet Access it is expected to have 30 terminal machines, all machines will use an electronic medical record web application we want ...
7
votes
4answers
828 views

Firewall Reviews - What is in your Toolbox?

In the vein of the questions about forensics, I'd be interested to hear what tools/techniques people use on Firewall reviews, both in terms of periodic reviews as an auditor or consultant, or ...
29
votes
7answers
8k 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 ...
9
votes
4answers
1k views

A firewall without any extra features [closed]

I have Kaspersky Internet Security (KIS) installed on my system. I always keep it disabled, yet using a few practices, I kept my system virus free for years: I disabled autorun using these tricks; I ...
0
votes
1answer
531 views

JUNIPER Junos Pulse - how to apply policy to device

We'd like to set up and use Juniper Junos Pulse on iphone and ipad for access to Corporate mail. We have juniper SA and have prepared the policy, but how do we apply the policy to the devices?
8
votes
2answers
249 views

Retaining institutional knowledge of a complex infrastructure (checkpoint, juniper, etc)

In the next month my functions will be expanded to include IT security (firewalls, VPN, PKI) in a big complex infrastructure. Can I ask you for advice on how-to be well prepared for it? What sorts of ...
8
votes
4answers
1k views

How can a company reduce exposure to packet spoofing? What solution should exist, but doesn't?

I'd like to understand what anti-packet-spoofing technology exists (or should exist) to verify an inbound packet. Maybe this is as simple as a Cisco ACL, Firewall Rule, implemented at the network ...
4
votes
2answers
357 views

What criteria do you use for evaluating Client-Side / Endpoint security products?

What features are important to you in client-side AV and Firewall products? Who benefits from these features? Managment, the end user, helpdesk. Are there features that are being 'sold' by the ...
7
votes
3answers
375 views

What tools are available for distributing and syncing firewall rule-sets to multiple devices?

I am looking for a solution to be able to distribute and sync firewall rule-sets to multiple devices. There are a few solutions out there such as Playbook by Matasano but it comes with an expensive ...
13
votes
7answers
3k views

Egress filtering on an office network?

With an office network most companies will use ingress filtering to add a level of security, however few take advantage of egress filtering to protect their networks. The use of egress filtering will ...
11
votes
5answers
315 views

What are the areas to focus on to protect users and devices?

What are the areas or technologies to focus on to protect users and devices? Are patching, antivirus and firewalls still the main areas? How do you defend against attacks against vulnerabilities ...
18
votes
1answer
4k views

What is a Web Application Firewall?

What is a Web Application Firewall (WAF) and what are some of the things to look for in an effective one? Why would you deploy a WAF instead of just an IPS?
60
votes
6answers
25k views

What techniques do advanced firewalls use to protect againt DoS/DDoS?

It is hard to protect a server against Denial of Service attacks, DoS/DDoS. The two simple ways I can think of is to use a server with much resources (e.g. CPU and memory), and to build the server ...