Network Security - securing network infrastructure and connections

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10
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3answers
549 views

Are there valid reasons for spoofing an address?

This is a corollary to the question Why don't ISPs filter on source address to prevent spoofing?. Are there valid reasons to spoof an address?
8
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4answers
481 views

CAM table attack in 2011?

Today's switches are vulnerable to CAM Table attack? https://secure.wikimedia.org/wikipedia/en/wiki/CAM_Table
4
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5answers
3k 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 ...
3
votes
7answers
817 views

Scanning A Subnet Externaly

Scenario: I have a router with a public IP address provided by the ISP and two hosts behind the router with a private IP (192.168.x.x). Is it possible to perform a port or vulnerability scan of a ...
15
votes
1answer
4k views

What are darknets, and how can they be used to provide security and anonymity in network communication?

One of the major problems with the internet is that it's difficult to stay anonymous while retaining the ability to communicate with a large number of people. While encryption can be done effectively ...
16
votes
5answers
8k views

Can I detect a MITM attack?

Based on this question here: Are "man in the middle" attacks extremely rare? Is it possible to detect man-in-the-middle attacks, and if so, how would one go about it? In addition, what if ...
12
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5answers
13k views

How to find out that a NIC is in promiscuous mode on a LAN?

How to find out that a NIC is in promiscuous mode on a LAN?
13
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3answers
1k views

VPS security best practice

I've just signed up for a linux VPS to host a website I've been creating and I need some advice on the best approach to secure it. I've previously been hosting it off a VM in the house, but I want to ...
22
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9answers
36k views

How secure is TeamViewer for simple remote support?

I'm deploying a web-based ERP system for a customer, such that both the server and the client machines will be inside the customer's intranet. I was advised in another question not to use TeamViewer ...
17
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2answers
31k views

What is the real function and use of a DMZ on a network?

I read the article on Wikipedia describing what a DMZ (demilitarized zone) is on a network, but am still failing to grasp both how it is set up (ie: is it within the main network or sequestered away?) ...
11
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4answers
292 views

What free tools or techniques exist to discover anomalies in network flows?

I have been using FlowMatrix. What do others do on the cheap?
7
votes
1answer
448 views

What are the main issues and best practice security controls when exposing SIP and H.323 to the Internet?

What are the main issues and recommended controls when exposing SIP and H.323 to the Internet (could be for voice, video, and instant messaging traffic or all three)? Specifically I'm looking for ...
7
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5answers
4k 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?
4
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6answers
7k views

monitoring outgoing network traffic

The graphs for one server that I am using are showing consistent 7.5 kb/s outgoing network traffic that started a few days ago. How can I monitor/log/capture/analize this traffic to see what is it, ...
22
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5answers
19k views

Is it still unsafe to email credit card number nowadays?

We all know not to do it, but someone emailed my credit card number and cvv code to my gmail. I'm wondering if the risk is so low I don't have to call to cancel my card. The email is sent from a ...
17
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4answers
1k views

IPsec (Internet Protocol Security) facts

Internet Protocol Security (IPsec) is a successor of the ISO standard Network Layer Security Protocol (NLSP). What are the advantages, disadvantages, other interesting facts regarding the protocol?
4
votes
2answers
2k views

Does Java applets reveal the real IP address, even when using proxy or vpn?

Can a Java applet reveal the original client IP address, when browsing through a proxy or a VPN? Why?
14
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4answers
1k views

Threat assesment for a captive portal

I am interested in setting up a captive portal on a wireless network. From what I understand I would do this by initially having all guests in a temporary vlan, moving them to the real vlan when ...
13
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3answers
683 views

Do any DNS registrars support multi factor authentication?

I am looking for a DNS registrar that supports strong multi-factor authentication. Does any DNS registrar support multi-factor? Is this a legitimate need?
12
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3answers
318 views

Verifying server software integrity?

I'm trying to brainstorm a security scheme for the problem of verifying server software integrity. The domain of this problem is Game Servers built on Valve's Source Dedicated Servers. These servers ...
11
votes
1answer
3k views

Is WPA2 WiFi protected against ARP poisoning and sniffing?

Is WPA2 WiFi protected against ARP poisoning? If not, can the ARP poisoner decrypt the packets?
10
votes
7answers
600 views

IP address black list

My website has a black list of IP addresses. The web application, in some way, detects all invalid, suspicious influences to it and remembers IP address and denies any requests from that IP address. ...
7
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6answers
1k views

How can I restrict access to network data by an unauthorized computer that connects via Ethernet?

I assume I can configure most routers to only assign IP addresses to specific MAC addresses, as is possible with wireless routers. However what if a computer is connected via Ethernet and does not ...
5
votes
4answers
1k views

Email header IP address

Do the IP addresses in an email header include information from the device from which the mail is being sent, or from the mail server?
2
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2answers
3k views

Using Cain and Abel to capture traffic of machine in the same network

I have installed Cain and Able in machine A, which is connected to another machine B via a LAN. Now I want to analyze all the traffic of machine B. Is this possible by installing Cain and Abel on ...
12
votes
2answers
5k views

How do Intrusion Detection Systems (IDS) work?

How do Intrusion Detection Systems (IDS) work? As I understand it, they monitor network traffic but what exactly do they look for? How can they tell apart regular activity from intrusions?
10
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4answers
535 views

Wireless Activity Monitoring for PCI DSS Compliance

In an effort to be PCI DSS compliant, I took a trustkeeper.net questionnaire. I failed the question that asks Is the presence of wireless access points tested for by using a wireless analyzer at ...
9
votes
3answers
515 views

Would publishing a network diagram make the network less secure?

I have found some social networking sites that focus on sharing architecture (network maps and diagrams) and configuration. Does sharing this type of information decrease the security of my network? ...
9
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2answers
914 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?
8
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1answer
423 views

Is it possible to recognise and prevent MitM attacks on devices which use self-signed SSL certs?

I use both Linux and Windows at work on a large enterprise LAN. The majority of the network configuration is out of my reach. Certain SaaS applications that are hosted locally on the enterprise LAN, ...
8
votes
2answers
3k views

Can an attacker sniff Mac addresses on a wifi?

If an attacker turns on wifi but doesn't have the security key to connect to an access point in range, can he still sniff packets that travel between the access point and clients connected to the ...
8
votes
2answers
377 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 ...
7
votes
3answers
477 views

Is IPv6 with NAT less secure than IPv4?

This is a follow up to a snippet from another answer. There, user Ninefingers writes: (...) only allow outbound connections, ever. Do this in spite of NAT as IPv6 will make those NAT defences ...
7
votes
1answer
1k views

Bypassing hidden SSID and MAC filtering “protection”

I was browsing over this question and had some follow up questions from a practical perspective. What tools will show the SSID of an AP with the SSID set to hidden or broadcasting disabled? I have ...
6
votes
2answers
3k views

Scanning my network with NMAP

Each computer is assigned one ip address on my network, and my ISP supplies one IP for my network. If I try to scan the ip supplied by my ISP what I got is the OS running on the router, running on the ...
6
votes
1answer
1k views

Security Operation Center (SOC)

I am looking for resources and details on establishing a security operation center (SoC) or network operation center (NoC) based on ITIL or any other applicable regulations. Where can I find good ...
5
votes
5answers
272 views

Does the method of Internet connection affect the security of your the network?

I was just visited by some door-to-door salesmen from a local ISP/TV/Phone provider. During our conversation, I raised some concerns about the fact that I knew their help desk techs had back-door ...
3
votes
5answers
852 views

Building my own Darkspace

I have searched through the internet about creating a darknet and there is a confusion. There are two definitions, the first one is network used for private p2p (like freenet) and another one that ...
3
votes
2answers
1k views

How do the root servers get updated with my name server? Is WhoIS information always in sync with the root?

I've never understood what happens behind the scenes when I go to my registrar and enter in my name server's information. Can someone elaborate on what happens when an update is made, and how it is ...
2
votes
2answers
1k views

how to identify p2p on network

Im trying to work out if the traffic in the below image is P2P file sharing? If you notice the source ports are all random but the time 17.24 from c.port 58338 runs for a good length maybe about 400 ...
1
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2answers
119 views

Isolating guest networks

I'm setting up a secondary guest wifi on my router and I want to make sure that it's impossible for clients connected to the guest wifi to access my primary network. Initially, I used IP filtering ...
17
votes
3answers
1k views

What are the risks of using a CDN to speed up my website? How do I avoid them?

Content Delivery Networks (CDNs) are well known to speed up the performance of a website, but they create the obvious security risks if someone were to change the code that resides on the CDN. What ...
10
votes
4answers
4k views

Looking for botnet IP address feeds to protect against DDoS

I would like to get a live feed of botnet IP addresses delivered from a service and block them under certain conditions. Preferably community based/open source but open to looking at worthy commercial ...
10
votes
7answers
2k 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 ...
9
votes
2answers
497 views

How does the Copyright Alert System work? Who has implemented it?

Some ISPs are participating in a Copyright Alert System that notifies content authors of violations of their copyright. I'm concerned how this oversight relates to my private traffic, and what laws ...
8
votes
4answers
3k views

Is NTP vulnerable to DNS poisoning or spoofing attacks?

Scenario: Attacker somehow compromises the DNS lookup for the NTP server used by the victim (a web application) Victim sends DNS request for e.g. ntp.pool.org, which is responded to by attacker to ...
7
votes
3answers
2k 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 ...
7
votes
3answers
786 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 ...
7
votes
6answers
241 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 ...
7
votes
3answers
407 views

Popularity of Anomaly based IDSes

I've been reading quite some time about anomaly/behavior based IDSes for Web servers. I understand the downsides: possible high false positives, learning phase, constant training. My question is how ...