IP and MAC address question!

[TheOne]

If I am connected to the internet and I use tor on my pc to access the net. I know the sites I access can't see my real IP and my internet provider can't see the sites I'm accessing. However can those sites see the MAC address of my PC or router or both?

Isn't the MAC address only used by the router to route the incoming packets to the right PC?

When one requests a page/site(without using tor) is the MAC address sent in the header of the frame as well over the net to the destination website or not?

[Kyonz]

Hi there TheOne, I only registered to give you an answer because misinformation is a nasty thing.

If I am connected to the internet and I use tor on my pc to access the net. I know the sites I access can't see my real IP and my internet provider can't see the sites I'm accessing. However can those sites see the MAC address of my PC or router or both?

This is incorrect, your IP address is shown on all connections that you make unless you go through some form of anonymous proxy. IP addressing is used for all communications on the internet and any site can see what your IP is and your provider could definitely see what you were accessing if they wanted to.

In regards to your MAC address nothing could see this, MAC addressing is used to transmit data between devices on the same segment (from 1 device to another in a direct path). So your computer talking to your router uses MAC addressing, then your router talking to your ISP uses it, etc etc.

Isn't the MAC address only used by the router to route the incoming packets to the right PC?

-Actually PAT (port address translation) is used to do this, an open connection is initiated on a certain port and all traffic back through that port is routed. Basically your computer opens the tunnel and all traffic to and from go via it this is via IP and not MAC addressing.

When one requests a page/site(without using tor) is the MAC address sent in the header of the frame as well over the net to the destination website or not?

-MAC address will always be in the header of the frame (Tor or not) but this is between devices on the same segment, as a packet moves from device to device the MAC address field changes. IP addressing is what is used for packets to navigate the internet not MAC addressing.

I hope this clarifies some of the confusion you are having regarding addressing.

[aprotosimaki]

Originally Posted by TheOne

If I am connected to the internet and I use tor on my pc to access the net. I know the sites I access can't see my real IP and my internet provider can't see the sites I'm accessing.

They can determine that you are using TOR but they will not know which sites you are accessing using TOR. So you are correct.

However can those sites see the MAC address of my PC or router or both?

No, the remote site has no idea of your MAC address.

Isn't the MAC address only used by the router to route the incoming packets to the right PC?

This is essentially correct. Basically the router knows it has a packet destined for, say, the machine at 192.168.1.5 so it consults its arp cache to determine that machine's MAC address. Once that is determined, it constructs an ethernet frame using that MAC address as its destination MAC and puts in on the wire.

When one requests a page/site(without using tor) is the MAC address sent in the header of the frame as well over the net to the destination website or not?

No it is not; the MAC address in the frame will have the source MAC address of the last router that routed the packet to that remote site, not your MAC address.

[TheOne]

Thank you for all these generous replies. I guess I was right all along thinking my router couldn't possibly send my MAC all the way to the destination source since the packets will/may have to make so many hops before they reach their final destination.

While we are on the subject of networking, I will confess that I'm an IT student. I would like to get my CCENT and eventually CCNA from cisco in the next few months. Can any of you professionals in the industry tell me if it'll be worth it? That is of course on top of the other required classes that I have to take.

PS. I'm taking a java class right now and I hate it. Is java a big deal to know well as an IT guy?

thanks all!

[opmrcrab]

Im a software eng, degree level, did Java at uni, been working for 3 years or so now in various industries.

Java is important for several reasons, its a strict OO language - and thats an important paragdim to learn - its got a beutiful API for both programming and online resources (go look at .NET), and while it runs like a dog is some situations (3D gfx etc) its a very powerful business tool.

Personaly .NET has been more widely adopted by the industry, so definatly get some practical exerpience with ASP and VB/C#, but in terms of transferable skills java to C# is so ez you can practicly copy/paste code between for like 80% of source files.

[wimiadmin]

I can't really speak for the java side of things, but I can add my 2 cents for the CISCO stuff.

Having run many large networks, the heart of all data transferring most likely will happen on a CISCO switch. With more and more companies moving to VoIP and needing good quality equipment that will handle QoS, in my opinion, CISCO is the only way to go. When we use to set up networks, we would just hire someone to come in with a CISCO switch and let them set it up while we took care of the rest (more cost effective than keeping a CISCO person on staff). I never made the time to learn more about their setup or configuration. I'm in a position now where I don't really need to know about this type of heavy duty equipment any more....but really wish I would've made the time to learn.

I say go for it. Get your cert. Even if you decide not to do hardware, it'll be something you can add to your resume and remember, the more well rounded you are with knowledge, the less likely you are to get pigeon holed in to a job you don't want.

[clanmills]

Hello TheOne

I think wimi and I might be unidentical twins (I know nothing about CISCO and quite a lot about Java). We're both engineers. Wimi makes stuff work, I do code. Maybe wimi is 'light matter' and I am 'dark matter'.

There are many facets to computer systems. If you want to be a 'coding guy', Java is a valuable skill. However if you want to be a 'network guy', Wimi's right - go for CISCO.

Knowledge comes in many forms. Knowing your limits and dislikes is as important as understanding your strengths. It sounds as though you've learned something very important on your Java course.

I think it's easy to hate Java (although I don't). In fact it's easy to hate most software. However once you know what type of guy you are, you'll find a place where you'll blossom and shine. Don't forget, most people will hate the world in which you thrive and be very pleased that you take care of that part of the enterprise.

Good Luck and have fun.

[TheOne]

Once again, thank you for these wonderful replies. My main problem with java is that it's hard for me to keep up. I've been behind in the class for like 5 weeks straight now and it seems like I will never be able to catch up

However, I think I really like the Cisco stuff. I'm sure it will get much harder as I go up in chapters, but at least I feel like I can't fall behind in it. But I would love to know programming (I guess I just dont like learning it) even if I will not work on that side of the industry. Perhaps once I get it, I'll love it more. That is if I ever get it.

Thank you very much. This site is wonderful. I'm grateful!

I'll come back with some more network questions for you guys later.

Good day

[clanmills]

I didn't start programming for a living until I was 33. I'm now 58 - so I've been cranking out code every day for 25 years. I've probably written around 1 million lines of code and read 10 million lines of other folks stuff.

When I arrived in the computer business (when I was 23), I quickly came to the conclusion that I wasn't cut out for writing code. 10 years later I realized that this was what I really wanted to do.

So don't give up at this Java hurdle. Be patient. Life is (quite) long and a journey down a different avenue such as Visual Basic or C++ may be better for you. Maybe configuring the network, testing, documentation, marketing, sales or management is your strength. We all face set-backs. This java course might be a set-back or a life-saver. Relax and let things come to you.

I don't know where you're located - however I'd be happy to tutor/mentor you with Java via Skype if you think that would help. Of course you may find my Scottish accent even more difficult than Java!

Robin