Network Security - securing network infrastructure and connections

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Should we configure all devices to never request SSL 2.0, and reject it if offered?

In an effort to reduce man in the middle attacks, when will it be (or was it) an industry accepted practice to reject SSL 2.0 connections on the client and server side? Is configuring this on a proxy ...
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7answers
3k views

Alternative to VPN

We have a network that is completely closed to the outside world. It needs to be. Problem is we need to remote into a server on this network once in a blue moon for diagnostics. We've discussed ways ...
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4answers
3k views

How can an access point spoof me into connecting?

I was reading through the answers of the question "How can I ensure that I connect to the right wireless Access Point?" and was wondering how it is possible for an access point to imitate another wifi ...
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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 ...
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4answers
4k views

How to break MAC address filtering?

If a MAC filter prevents you from connecting to a network, how can you break it or include your device's MAC in that filter?
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2answers
574 views

How were weak passwords brute forced in github?

Github faced a brute force password-guessing attack recently that involved "nearly 40K unique IP addresses". Passwords were also "stored properly" using bcrypt, (salt + hashed). Given that bcrypt ...
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5answers
30k views

Multiple VPN clients in parallel

If I were to run more than one VPN clients on my machine, simultaneously, what risks would be involved? E.g. are there technical conflicts, such that it wouldn't work right? Could there be ...
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1answer
3k views

Backtrack 5 in a VM - Why bridged networking over NAT?

When running Backtrack 5 from a VM, it is recommended to use the bridged networking option instead of the NAT networking option? How does it affect the usage of Backtrack - port scanning, ...
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2answers
10k views

How can someone hack my PC if I am connecting to the internet through NAT?

If I own a private IP address, 192.168.2.1 for the sake of it, and I am physically connected to my router, which it's internal interface is 192.168.2.254 and it's external interface is some public IP ...
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4answers
415 views

How to design a home network for IoT devices?

I'm trying to work out how best to design a home network which contains (potentially hostile) devices. I'm running into my limits of networking knowledge! I have two challenges. Unsecure Devices ...
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2answers
3k views

Bypassing a reverse proxy/NAT

Reverse proxies and NAT would seem to obscure a network behind such technologies to the point where it would be hard if not impossible to identify ports open and services running. Given that many ...
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3answers
590 views

Tools needed to setup a paranoid remote backup server

I'm a system admin with little security experience. I want to schedule the copying of our backups to protect our data in case of fire. The best solution would be to copy the data onto a new hard-...
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1answer
3k views

ports blocked by firewall and not the server

I was asked this question at an interview and i wasn't sure about the answer. The question was "suppose you were checking the open ports on a particular webserver which was behind a firewall, how ...
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2answers
2k views

Malware known to use port knocking to evade detection by network scanners?

Are there any known cases of malware in the wild that utilize port knocking on a backdoor to evade detection by network scanners?
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2answers
1k views

Online SQL Server database for a Business app. Security considerations

A business application works with a SQL Server database. A SQL Server 2008 is installed on one of the computers of the local network. Technically this app works OK if the server computer with the SQL ...
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2answers
153 views

Using Single Domain Name to Identify Multiple Servers Improves Security? (Google's use of 1e100.net)

Since 2009, Google has been using a single domain name to identify its servers across multiple products: Following standard industry practice, we make sure each IP address has a corresponding ...
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4answers
4k views

extract from pcap all protocols found

I have some pcap files, and i would like just to get a list of protocols that are present on that pcap file. I would like it in a batch mode, not using wireshark I think tshark is able to do it, but ...
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8answers
823 views

Battling Malware without spending money

Our environment consists of about 80 users running Windows 7. Previous to me showing up as a full time IT employee, the company had contracted an outsource IT solution. As part of their set up, they ...
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3answers
659 views

Is secure Caller ID possible for SIP / VOIP?

Is there any way (standard, proposed or draft) that will allow for secure Caller ID over SIP / VOIP networks? I have constantly heard that Caller ID is insecure when used over these services. Can ...
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4answers
381 views

What are the main security considerations that must be taken into account if you intend on creating a (localised) whistleblower website?

Also: Is it something that can be achieved with limited funds? I ask because I am intrigued by the obstacles that are in place.
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6answers
16k views

How to detect eavesdropping by your ISP

I've noticed some funny behavior lately with my home Internet connection such as connections dropping frequently, rate limiting occuring, and packet loss. I know how to get around this online, use a ...
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2answers
13k views

Recommended Cipher Suites for TLS 1.0, 1.1 and 1.2

There are a lot of cipher suites defined in the in the specifications itself of TLS 1.0, 1.1 and 1.2. And furthermore, there exist RFCs which add even more cipher suites to a specific version (e.g. ...
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3answers
7k views

Security measures for a WiFi access point?

I am planning to purchase a program that comes with an App that allows you to control the program via phone. The developer told me that the connection will be done via an extra WIFI box connecting to ...
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3answers
1k views

Can an attacker “simulate” a private IP address?

I have a SSH server with a rule that does not allow password connections outside the local network. So people already on the local network, either physically or via VPN, are allowed to connect with ...
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2answers
20k views

Is NAT Loopback on my router a security problem?

Some DSL routers prevent NAT loopback. Security is sometimes cited as the reason. Is NAT loopback really a security issue? And if so, how is this exploited? NAT loopback... where a machine on the LAN ...
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9answers
609 views

Which factors should you take into account when deciding whether users should be informed of a penetration test?

Say you are conducting a penetration test of an internal network. The internal network comprises of workstations, servers and company and contractor laptops. In an ideal world, the penetration test ...
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4answers
1k views

How to determine if a VPN provider respects data confidentiality?

I've read about why I really should use a VPN and I've been looking into different providers, but there's one thing I'm worried about. Can't a VPN provider just look at my traffic all they want and ...
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1answer
981 views

Checksums do not match when I download file over http

Just for the test I did the following: Downloaded a page from wikipedia via wget on remote server and named the file test.dat. Then I executed md5sum. I download the file via http and check it back ...
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1answer
208 views

Long running SMTP session

I recently noticed an SMTP session on my server which started when a remote host connected but never seemed to result in any emails being delivered. I could see that it was probably a SPAM site and so ...
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3answers
898 views

How did the spammers get this address?

A few months ago I configured a test mail server on Amazon AWS, all legit. I used a new address to my catchall-domain (something similar to, but not exactly, test-config-aws-neptune-2014-08@my-domain....
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2answers
577 views

How do you Secure VOIP in a large organization

As part of a large organization looking to implement VoIP, to get on the bandwagon of savings and converged network focus, I'm being asked to look at the security concerns to develop a policy to help ...
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2answers
708 views

How to implement secure device identification in a for-pay wifi router to prevent usage fraud?

After reading this question about how for-pay wifi routers identify specific devices it got me thinking about what a secure alternative might be. I know that certain research has focused on ...
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3answers
2k views

Secure PXE network OS installation

How can one make sure that when PXE is being used to boot a remote operating system, that the data being sent is encrypted (or at the very least that integrity is maintained)? Would it be possible to ...
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2answers
3k views

How bad is the leaking of Internal IP addresses through external DNS

If an external DNS server is leaking internal IP addresses are there any significant security threats associated with this information leakage? Apart from most the obvious - gaining an understanding ...
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1answer
472 views

How to protect a Wifi network from Microsoft WiFi Sense

Microsoft is deploying a new feature, WiFi Sense, which provides users a way to easily share passwords to wireless networks with all of their contacts. This introduces a new security failure mode: a ...
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1answer
5k views

Obtain credentials by spoofing WPA/WPA2 Enterprise network?

I have a large scale wireless network secured using WPA/WPA2 Enterprise authentication. Recently, I was made aware of the possibility that someone may use a dd-wrt router and a computer to spoof the ...
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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 ...
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6answers
2k views

Dual Router Configuration

I have a home network that was hacked into recently. The people that got into my network actually accessed my personal files and although I cannot prove it, I think they might have stolen some of them....
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8answers
31k views

How to block some websites and torrent usage in a small office?

In my office there are approaximately 25 systems are connected through network and all having internet accessibility.but some people are missusing this facilities like downloading films from torrent ...
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5answers
8k views

What kind of attacks against home router's NAT do exist?

I always thought NAT was some kind of a security feature and I still think it is, because if it didn't existed the internet, respectively the clients behind NATs, would be even more insecure, since ...
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4answers
29k views

How to tell if you're being ARP poisoned?

I am having some issues at work and there is a new network admin in place. I think I am being monitored so decided to run ArpSpy X in two scenarios: Over WiFi bridge pluged into cisco router to took ...
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10answers
690 views

networking and security

I'm trying to pick up networking security within a reasonable amount of time. I'm not specifically looking to learn about all the little tools that are available (although I do want to know about ...
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1answer
1k views

Does restricting the names of computers allowed to connect to a wifi network provide any security

In response to a statement elsewhere that MAC address filtering was essentially useless for protecting a wifi network because it was trivially by passable by network attack tools, I was asked if the ...
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3answers
13k views

How to protect myself against paid DDoS services?

I am domestic user and I am getting attacked regularly by a guy that hates me. Here is the background story: that guy uses Skype resolvers (tools offered by paid DDoS services) to find out my IP ...
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4answers
8k views

Is the US military secret network SIPRNet physically or cryptographicaly separated/secured?

I've read the Wikipedia articles on SIPRNet and NIPRNet (which are pretty light on details) and they are supposed to be considered separate. At the network level, are they technologically ...
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5answers
1k views

What Man-made Physical Threat Could Pose Severe Danger to a Server Farm?

I am writing a novel in which a researcher attempts to work against a study he is a part of by purposely sabotaging operations on the research compound. I am wondering if the following is plausible. ...
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2answers
5k views

Using RSA with 3DES instead of plain 3DES. Does it make sense?

I have a large legacy code. Currently it is using 3DES encryption for a network based application. It encrypts data packets with a main key. This key is used to encrypt and decrypt (symmetrical). And ...
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2answers
11k views

How to be safe from wifikill!

I recently found that my friend is using wifikill apk on his rooted android and I would like to get rid of that software as I always get kicked from my wifi. I have to give him the password of my wifi ...
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2answers
363 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 ...
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4answers
9k views

How to detect hosts running in virtual machines with nmap?

I have to determine if a given subnet has virtual hosts. Are there any ideas about what switches to use?