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.

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3k 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
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3answers
2k 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 ...
16
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12answers
24k 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 ...
16
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3answers
7k 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 ...
13
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5answers
2k 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 ...
12
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4answers
5k 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 ...
8
votes
1answer
3k 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 ...
8
votes
3answers
9k 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 ...
7
votes
4answers
6k 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 ...
7
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2answers
5k 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 ...
7
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4answers
2k 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 --> ...
6
votes
4answers
772 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
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5answers
13k 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 ...
6
votes
3answers
264 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
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1answer
4k 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
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2answers
2k 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 ...
6
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. ...
5
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3answers
7k 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 ...
5
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3answers
5k 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 ...
5
votes
3answers
449 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
1answer
5k 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 ...
5
votes
2answers
879 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
4answers
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
2answers
8k 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 ...
5
votes
3answers
328 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
1k 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
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8answers
740 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
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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
743 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
256 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
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0answers
36 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
283 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
1answer
143 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
205 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
1answer
351 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
2answers
427 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 ...
3
votes
2answers
132 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 ...
2
votes
4answers
412 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
945 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
2answers
550 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?
2
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3answers
12k views

Access router if you don't know password

At home I have a wireless cisco router. Unfortunately I wasn't smart to change its ip or passwords. So anyone who is connected to it can access 192.168.0.1 and log in as admin using password admin and ...
2
votes
3answers
927 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 ...
2
votes
2answers
3k 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 ...
2
votes
2answers
677 views

Does “loose source and record route” drop the source address?

Is the source IPv4 address lost when a person uses "loose source and record route" and the destination address is put before the end of the list of addresses through which routing should occur? It ...
2
votes
3answers
24k views

How to bypass restrictive mac address filtering on home network (not malicious)

Background A short sketch of my situation before I formulate my question: I am on a large home network, which is privately administered by a couple of admins. The network consists of a lan and a ...
2
votes
1answer
133 views

find hardware and OS specs on routers

How do you determine the model and IOS version of a Cisco router, if you have its IP address remotely, but have no physical access. For example, I run nmap -sP and can see the router's IP, but all ...
2
votes
1answer
533 views

How do Cisco devices identify routers?

Our network administrators forbid the usage of private routers in our college. They bought new Cisco equipment (routers, switches) which detect routers and automatically ban them (it disconnects the ...
2
votes
1answer
124 views

What features boost security for a home edge router?

I want to hide my home network behind a router and not worry about firewalls on internet-facing devices. Furthermore, one PC is going to be hosting some services, so I guess I need port forwarding as ...
2
votes
1answer
542 views

Loki How to crack the password hash OSPF?

I have created for myself a lab of routers in GNS3 . Routing protocol between routers is OSPF. Now,by Loki penetration testing, I found that routers are the feature authentication. Using wireshark, I ...
2
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3answers
1k 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 ( ...