CTS/RTS, WIFI wireless and CSMA/CA

I need an assistant to answer the following questions:

Given a WIFI network in the drawing. The large circles represent transmission ranges of stations A and D, and small dashed circles represent ranges of B and C. Assume that there is no loss of parcels on the network other than a collision.

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  1. When Station C transmits to B Who are the hidden terminals?
  2. When station C transmits to B which stations are silent because they received an RTS/CTS message?

Given that Station A transmits to B and after expansion time Station C wants to transmit to D.

  1. Assume that no collision detection/collision avoidance/ACK mechanism exists. Hanna claims that only C’s message will reach her destination. Is Hannah right? necrosis.
  2. In the directive that only uses CSMA/CA (i.e. without the RTS/CTS mechanism), Anna claims that only A’s message will reach its destination. Dana claims that the 2 messages will reach your destination. Who is right? necrosis.
  3. Oren offered to improve utilization by upgrading the protocol by adding an RTS / CTS mechanism. Is Oren right?


Assuming I’m using Starbucks Wifi, is there a point of using a VPN if I want to remain anonymous?

Wouldn’t using Starbucks Wifi make me somewhat anonymous since my ip address would be the same as other users connected to the same network? Therefore, no need to use a VPN assuming I don’t want the website I’m connected to know my identify. Of course, the website can figure who I am assuming my browser fingerprints is unique. However, assuming I change my browser fingerprints every session, then I should be fine. Correct?

Personal computer + employer’s WiFi [duplicate]

I decided to use my personal Macbook at work, so I’ll be using my employer’s network connection. But I’m really concerned about my privacy. I know I can do non-work stuff using Tor Browser or Brave’s Private window with Tor, but what about my reminders, notes, voice memos and other Apple’s built in apps? I am really freaked about my personal stuff. How can I prevent them from accessing it? I know they may never do it, but if there is even the smallest risk, I want to prevent it somehow. Let’s say I create another user account specifically for work without logging my Apple ID and use it, will it prevent them from accessing my data stored on another (personal) account?

Firewall for my devices (iPad, iPhone, surface) on a shared home WiFi network?

I am renting a room and using shared home WiFi network. The owner has setup a Netgear WiFi range extender for me. I have another roommate on the same network along with the owners. I use Nord VPN. Since a few months I have been getting weird emails…someone opens accounts (like Snapchat, SoundCloud, Pinterest etc.) in my name constantly. I close one account and two more gets opened. I accessed those accounts and they had photos and stuff, so someone had been using them. I noticed that date of birth in one account was a date of significance to me (not my dob) and year in the username was a significant year related to that date. So it is confirmed that I’m hacked. On top of that yesterday I accessed my new website hosting service and made some changes to start a website, today this person opened an account for hiring employees. I believe someone can access (Hack into) my devices through home WiFi. Is there a way to monitor who is accessing and stop it in real time like a firewall. I use iPad and surface pro. Any advice to secure my devices?

What is the best form of authorization for captive portal WiFi

I’ve been looking into captive portal WiFi implementations and on a few I’be been able to easily bypass their login with the following steps:

  1. 1) Open Wireshark and run a report getting the most used IPs in my network (except the router’s IP and mine)
  2. Chang my mac address to that IPs associated mac
  3. refreshing the NIC

My rational was that it seemed like most captive portal just redirect all your traffic to a login page, once you login it seems to whitelist your mac. So I just found the IPs that had the most traffic that were on my network and assumed they are probably already authorized to use the internet. Sometimes it takes a few tries to get the right mac, but this normally works. I’m wondering what other better authentication methods are out there that solve this problem.

Breaking Wifi password knowing its length of 8 [A-Z] alpha (upper-case) characters using Hashcat

I got the WPA handshake, now it’s turn to crack the password using Hashcat. First, I wanted to make a wordlist of passwords [A-Z] the length of 8, but Crunch (the tool in Kali Linux) said it will take 1TB of storage that I don’t have available, so I gave up that way. Is there any way to generate passwords (example: ABCDEFGH) and delete them after its use one by one, during the cracking process?

How long does it take to crack the password with i5-3320M CPU using Hashcat? Is there any other way you recommend?

How to stop malicious WIFI from doing (whatever it wants to do)?

Was reading this: How to check if a Wi-Fi network is safe to connect to?

When I came across some comments

I can redirect you to other pages without your interaction. Install key loggers. Heck if your browser runs activeX objects I could open a shell on your machine without your knowledge. That last example is rare these days but what’s not rare is tricking you into installing a shell for me, keylogging, session stealing, and redirection.

Or as I mentioned in my post, drop a crypto miner on your machine with the tool I wrote

Written by Anthony Russell in the comments of his answer.

So, this looks bad, obviously. What I want to know is how can I stop these attacks? Blocking javascript sounds like a good start, the original post also suggested to check my device for open ports (they did not demonstrate how to shut them though). What else? Is there a fool-proof way to prevent these sort of (virus injection? remote control?) attacks? I am not talking about logging, though. That’s a given when you connect to any network.

What I’m most worried about is virus injection. But other attacks (like key loggers) mentioned above are concerns too. Just share whatever comes to mind. I’m sure other people will fill in the blanks.

Sorry if I sound like a complete noob. That’s because I am. Sorry in advance.

Can a malicious WIFI network force a connection

Say I enter a place with public WIFI. Of course, I would not connect to the network since I know it’s risky, but I do have my computer turned on. Can an attacker know my computer is there and force a connection to it? If they would be able to do so, than my precaution is wasted, and any attacks a malicious network could do would be done.

Telling me whether this could be done and how to stop it would be very helpful, thanks.

As a sidenote, connecting to a known network may not be safe either, could hackers “replace” an existing network with a malicious network with the same name? If so, how to protect myself against it?

Can the ISP (or anyone spying on my WIFI network) see which VPN IP I’m connecting to?

I know that even when connected to a VPN, the ISP (or anyone who controls my WIFI network) could see that I am connected to (A VPN brand), what I would like to know is would they obtain the exact IP that I’m connected to.

As a side note, what could the ISP really see when I use VPN? I imagine packet size and frequency should be compromised, but what else? (MAC? hostname? DNS info?)