Routing is the process of moving packets across a network from one host to a another. It is usually performed by dedicated devices called routers.

learn more… | top users | synonyms

28
votes
3answers
8k views

How can a webpage get the MAC address?

I was logged on to my router and filling out some information. I clicked a button and a field was automatically filled in with my computer's MAC address. How is this possible? Does it present a ...
22
votes
3answers
3k views

What does the email header-line “message opened by mailclient” mean?

Today a Belgian MP claimed (backed up by a security expert) that her email headers show that her email was read during routing (text in Dutch). The published screenshot of the headers highlights the ...
21
votes
12answers
38k views

Public DMZ network architecture

Years ago, when I was a student, a network security professor taught me in a class what a DMZ is. The architecture he used in his slides was similar to this one: Now that I got employed, my boss, a ...
18
votes
3answers
12k views

Router password vs MAC filtering?

I just bought a Galaxy S4, and it didn't connect to the WIFI in my house (I have a 14$ router). After a bit of testing, I've decided to leave my connection open without a password, but added the ...
17
votes
5answers
1k views

How secure is binding to localhost in order to prevent remote connections?

Let's say we're running a service that's bound to localhost (127.0.0.1), and the goal is to only allow local clients (i.e. from the same machine only) What techniques might be used to break this ...
17
votes
4answers
10k views

Can home routers get infected?

I am behind a router(linksys that runs dd wrt on it) and I was infected with sality. I'm curious, can my router get infected too? If yes, how can I remove the infection? I used the search bar but ...
13
votes
5answers
3k views

Access to a router's GUI

During a recent visit to a coffee shop, I noticed that they hadn't bothered changing their default user name and password for their router. I realise that someone could log on and be annoying to ...
11
votes
0answers
1k views

Attackers of Google DNS hijacking

As we know Google DNS server (8.8.8.8) in 14th and 15th March was hijacked in Sao Paulo. And subsequent to this event, BGPmon.org announced an alert. Now, In a course assignment, we are asked to ...
10
votes
2answers
15k views

What are the security implications of enabling UPnP in my home router?

I found port forwarding entries in home router that I haven't manually configured. Is that because of UPnP? Are applications simply able to tell the router to forward ports on their own? Are there ...
10
votes
1answer
5k views

How can I stop this DOS attack?

I have this entry appearing constantly in my router logs: [DOS Attack] : 5 [RST Scan] packets detected in last 20 seconds, source ip [xx.xx.xx.xx] They just never stop. It doesn't seem to affect ...
10
votes
3answers
11k views

How to best set up public WiFi without giving access to the rest of my network?

For reference, this is just for my home network. Anyway, I have quite a few of my neighbors ask me to share my internet with them. I'd really like to eliminate this "here's the password" portion ...
9
votes
3answers
17k views

How does “traceroute over TCP” work, what are the risks, and how can it be mitigated?

There is a utility called tcptraceroute, and this enhancement called intrace that is used just like a standard traceroute, but it works over TCP. How is the syn flag in TCP used to achieve ...
8
votes
4answers
7k views

How is Tor secure?

If Tor is open source and thus its process of concealing your IP is known, then how does it keep anything secure? Couldn't someone look at the source code and figure out how to reverse the routing ...
8
votes
5answers
21k 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 ...
8
votes
2answers
218 views

Why does Tor use a new route every few minutes

As far as I know, Tor selects three new nodes every few minutes. What is the advantage of this? The only thing I came up with was to prevent "Bad exit nodes" from viewing too much of your (hopefully ...
7
votes
4answers
3k 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 --> ...
7
votes
1answer
1k views

DSL Modem Compromised?

Just found out that the primary & secondary DNS servers have been changed to 95.211.156.101 & 5.45.75.11. I had the following setup in place. MAC filtering and WPA2 for WiFi. ...
6
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 ...
6
votes
3answers
8k views

Why do I need a firewall on my router?

I just bought a new router, and as usual the router manufacturer make a big deal out of the firewall. I have never understood why the firewall is needed, sure, stopping dos attacks (such as ...
6
votes
5answers
5k views

Is dd-wrt generally more secure than manufacturer's firmware?

I have been advised to use dd-wrt, for richness of features and heightened security. The argument about security is that major manufacturers don't care much about the firmware, release with a lot of ...
6
votes
3answers
730 views

Out-of-the-box Network Intrusion Appliance for non-Power User

First, let me apologize if any of this question is naive or beneath the scope of this board. Bear in mind the context and that I'm asking as an attempt to exhaust all resources. Also, I understand if ...
6
votes
1answer
12k views

Firewall defined Akamai IP Range [closed]

With obvious dangers of opening up a wide range of ips, does anyone know how I can get a source of IP ranges for Akamai? When talking to Akamai they say 'not possible' which I find surprising. I ...
6
votes
1answer
8k views

What is packet drop, packet loss and how Packet drop attack works?

I confused with the three terms: Packet drop. Packet loss. Packet drop attack.
6
votes
2answers
14k 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 ...
6
votes
2answers
3k views

Strange STP traffic in my network, possible MitM attack?

I live at a student dorm, where we are connected to a student network. The administrators of this network have forgotten to disable STP broadcast on non-infrastructure ports. Periodically, I lose my ...
5
votes
3answers
535 views

Solaris: IP Spoofing Across Ethernet Ports

Given a Solaris machine with two network interfaces corresponding to the separate ethernet ports in the back. 0: 192.168.0.5/255.255.255.0 1: 192.168.1.5/255.255.255.0 with /etc/defaultrouter set ...
5
votes
2answers
2k views

Encryption of headers in IPsec tunnel mode

I am learning about IPsec's transport and tunnel modes. I understand that transport mode encrypts only the payload of an IP packet and is used for communication between two entities that both ...
5
votes
3answers
2k views

Two SSIDs on same Access point- not good?

If I were to offer two networks (one for trusted users and one to visitors) on one physical access point, is this dangerous because a visitor could compromise the trusted network across via the ...
5
votes
3answers
363 views

Forensics on a SOHO router

I am interested in how reliable the information determined from doing forensics on a SOHO router is. Most of these routers don't seem to be very advanced, so I question if it would be possible to ...
5
votes
1answer
2k views

Recent Fritz Box exploit

Background info: About 50% of the ADSL and cable internet access in Germany (and presumably parts of the EU) goes over AVM Fritz routers, either verbatim or rebranded as e.g. "1&1 Home Server" or ...
4
votes
8answers
997 views

How can I be sure that an intranet app is absolutely not accessible from the internet?

I am developing an intranet application using Apache/MySQL. The server hosting it does not have a public IP address itself, but can access the internet through a router. There is not any sensitive ...
4
votes
3answers
502 views

How to track back a dynamic IP address?

Is there a way to trace back who was using a public dynamic IP address previously? Would it be possible to find out the MAC address of the host using the IP address at a given time? (e.g., can you ...
4
votes
2answers
2k 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 ...
4
votes
4answers
1k views

Can the loopback interface be hijacked?

Inspired by this question I came up with this weird idea of making what that user actually wants to prevent. So, bear with me for a little bit: Let's assume that for some reason we could make the ...
4
votes
1answer
297 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 ...
4
votes
2answers
179 views

Provider can access my local network?

I recently talked with my ISP about many things, basically related to my (little) company security, this guy is a networking guru to me, but he did a strange thing that worries me. Basically I have a ...
4
votes
1answer
986 views

Is my ISP BGP/DNS hijacking?

I've noticed some very suspicious activity from my ISP. Sometimes I would notice that when I ping google.com it would resolve to an IP which is owned by my ISP. I currently don't have an example ...
4
votes
0answers
42 views

How does BGP filtering work to prevent routing hijacking? [duplicate]

I've been reading for a while but yet do not properly understand how is BGP filtering used to prevent "attacks" such the recent Indosat's problem. Do not copy&paste Cisco's site, I have read all ...
3
votes
4answers
356 views

What does a switched network protect us from? What does it not protect us from?

There seems to be some misconceptions regarding what a switched network will protect us from, and what technologies/precautions a secure environment requires when segmenting trusted users from hostile ...
3
votes
2answers
243 views

How can I obtain the internal IP of a computer behind NAT but reachable via certain TCP port?

I want to obtain internal IP of a remote computer behind a NAT that I can reach by using some port, say myhost.farfar.away port 11122TCP: C:\>telnet myhost.farfar.away 11122 ...
3
votes
1answer
209 views

What are the requirements to sniff UDP packets in a Wireless Ad-Hoc network?

In a wireless Ad-Hoc network, I have two computers which communicates in UDP together from 192.168.1.3 to 192.168.1.5 I have a third computer (192.168.1.6) which wants to listen to the packets which ...
3
votes
2answers
5k views

do different subnet masks on home network provide any security?

So I have two routers on my home network: one is provided by my ISP, and the other is my private router. Router A- ISP router: 192.168.1.x router B- private router: 192.168.2.x Clients on my ...
3
votes
1answer
637 views

How is a Tor hidden service immune to exit node attacks?

Let me explain with a nifty diagram: IP/RP <-> bunch of Tor clients/node (Tor circuit) <-> Tor hidden service Wouldn't the last Tor client in the circuit knows that the message is for the Tor ...
3
votes
1answer
373 views

Security of Openflow/SDN network

Openflow/SDN networks give a remote controller the ability to manage the behavior of network devices i.e. configurations. They can forward instruction sets to dynamically change network configuration. ...
3
votes
2answers
213 views

Software suggestions on building a “passive” and “active” WAN simulation and fuzzing device?

I want to build a more-or-less self-contained box that I can plug two or more endpoints into (routers, mainly) that will simulate a WAN. I want to be able to mess up traffic in all sorts of ways, both ...
3
votes
2answers
542 views

1 PIX firewall, 2 routers, 2 switches. Please answer a couple questions about hack lab

I bought a bunch of cisco equipment for a project and I got 1 PIX firewall 2 switches and 2 routers This is my plan for a topology but I am new at this so I need help. I am basing this off the ...
2
votes
4answers
485 views

Securing private IP space

As we all know, routers that you buy from the store come preset to hand out IP addresses using DHCP, generally on one of three networks: 10.0.1.1/24, 172.16.0.1/24, and 192.168.1.1/24. I personally ...
2
votes
4answers
1k views

Best way to push data to a client without being blocked by firewall

I'm asking this question here since I think people on this forum probably have the best knowledge of firewalls and routers. Say I'm designing a multi-player game and I want to push data to the client ...
2
votes
4answers
2k views

Can anyone tell if a wireless router is plugged into an Ethernet port (without actually seeing it)

In a large network if there is an Ethernet port in the wall, is it possible to tell if a switch or wireless adapter is plugged into it? (I'm talking about the cheap home routers - with the built in ...
2
votes
2answers
753 views

How actually is Tor hidden service hidden from public?

Let's suppose I have a web server X, listening on port N for instance and configured as a Tor hidden service. How and where is implemented its' hiddenness from public access?