Samba, ssh and unmanaged switch

I am having a problem understanding this: if I have pc1 (acting as a samba server) connected to an unmanaged switch, how does pc4 also connected to an unmanaged switch browse pc1 shares or try to ssh into it if an unmanged switch only uses mac addresses?

Both unmanaged switchs are behind a netgear router, so same subnet: /24.

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Comments

dustinmurphy

A switch is a switch is a switch... managed or unmanaged (as long as it's not a L3 switch)... the unmanaged switch just means that it doesn't support VLAN, etc. This puts all ports in the same VLAN. As long as you're running TCP/IP (which addressing and L3 routing is being handled by your router) you have connectivity (as long as your PC1 and PC4 are using the same subnet addressing.) The switch gives the network L2 access for which L3 can ride on.

Edit: this is assuming you have a link between the 2 switches.

binaryhat

The two unmanaged switchs are connected directly into the router.

So I guess what I am asking is:

1) For ssh can I still do 'ssh binaryhat@192.168.1.101 -p 50001' behind a switch?
2) For Samba can I browse by ip address? I assume I can browse by netbios name...

dustinmurphy

binaryhat wrote: »

The two unmanaged switchs are connected directly into the router.

So I guess what I am asking is:

1) For ssh can I still do 'ssh binaryhat@192.168.1.101 -p 50001' behind a switch?
2) For Samba can I browse by ip address? I assume I can browse by netbios name...

I'm sorry... I don't understand how you have A+, Network+, and Security+ and NOT know the answer to those 2 questions. Not sure if trolling... or...

Either way...

BEHIND a switch? A switch is the basic unit (these days, anyways) for layer 2 connectivity, which is required for the remaining layers of the OSI model to function.

Assuming that you have TCP/IP configured correctly, here's the answers:

1) Yes.
2) Yes.

I am assuming you're using a *Nix host for Samba and SSH.... as long as you have SSH configured to answer on port 50001.... should work. Assuming you are using *Nix, Netbios may not work, depending on your configuration. IP address should work.

The question I have for you is...

Did I just get trolled?

binaryhat

Did I just get trolled?

No.

I was having a difficult time grasping the concept. I understand the difference between L2 and L3 devices. I was just hitting a brick wall when it came to how the application layer stuff which use ip addresses would function when used behind a switch. It's new terrirtory for me. Trolling is not my intent at all.

dustinmurphy

Ok. It just seems like a very elementary concept to me... especially considering you claim to have 3 certifications, one of which has a distinct focus on networking concepts and the OSI model, specifically the devices you are hitting a "brick wall" on...

The next question I have for you... if this is a "new" concept for you... what were you using previously?

I'm having a hard time with understanding how someone can configure SSH with a non-standard port... and Samba on a *Nix box without at least the concept of how a switch works....

Note: I'm ALWAYS willing to help, as I tried to do previously. It just seems to me that someone with the credentials you claim to have should understand the basics of network connectivity. I have seen some of your other posts, and they seem to focus on ICND1/2... if I were you, I would review the Network+ topics and get a good foundation of understanding of networking concepts, before trying to move forward with much more difficult material. Either way... to each his own... and I hope I helped you with understanding...

Zartanasaurus

I'm going to answer your question with a question. Switches forward frames. What do frames have inside of them? What does a host do when it receives a frame addressed to it?

binaryhat

Zartanasaurus wrote: »

I'm going to answer your question with a question. Switches forward frames. What do frames have inside of them? What does a host do when it receives a frame addressed to it?

Frames contain the preamble, CRC, payload, src and dst MAC Address. When a host receives a frame addressed to it, it strips/removes it. A frame is a L2 PDU. Yes?

it_consultant

binaryhat wrote: »

I am having a problem understanding this: if I have pc1 (acting as a samba server) connected to an unmanaged switch, how does pc4 also connected to an unmanaged switch browse pc1 shares or try to ssh into it if an unmanged switch only uses mac addresses?

Both unmanaged switchs are behind a netgear router, so same subnet: /24.

You have to learn ARP and DNS in order to really understand what is happening. Cutting out DNS, it can be explained this way. If I call another computer on layer 2 by IP address, my computer ARPs a request to know the MAC address of the IP I am calling for. The switch broadcasts that ARP to all ports until the target computer responds. The switch locks the conversation between these computers to only the 2 ports on the switch (this is the difference between a switch and a hub) and they can talk.

Open a command window and type in "arp -a" and see what you get. Higher in the OSI protocol chain you get DNS and WINS which allow you to call by an ASCII name as opposed to an IP address. The results of the "arp -a" will be the same. If you type in "ipconfig /displaydns" you will get the hostname to IP address. With all that information your PC has (hostname to IP, IP to MAC) your PC is able to resolve the other PC by name and browse its shares.

Zartanasaurus

binaryhat wrote: »

Frames contain the preamble, CRC, payload, src and dst MAC Address. When a host receives a frame addressed to it, it strips/removes it. A frame is a L2 PDU. Yes?

What's in the payload?

binaryhat

Zartanasaurus wrote: »

What's in the payload?

The data that is being trasmitted across the network. It has a MTU of 1500 bytes.

Zartanasaurus

binaryhat wrote: »

The data that is being trasmitted across the network. It has a MTU of 1500 bytes.

So the SMB data is in the frame. The destination is in the frame. The switch forwards frames. Why would the switch only knowing MAC addresses prevent the PCs from communicating?

binaryhat

Zartanasaurus wrote: »

So the SMB data is in the frame. The destination is in the frame. The switch forwards frames. Why would the switch only knowing MAC addresses prevent the PCs from communicating?

Hmmm...stuck on that one...

Well...an unmanaged switch means the ports are on same VLAN so that's not the answer...

Port is being blocked??

dustinmurphy

binaryhat wrote: »

Hmmm...stuck on that one...

I believe this is where it_consultant's post comes in. Although the SMB data is in the frame payload, TCP/IP tells the packets where to go, right? ARP is just like DNS, except it translates an IP into a MAC address... the packet information contains source IP and destination IP. ARP allows that information to be translated to MAC address the switch creates a connection between those 2 MAC addresses.

Just because a switch is "unmanaged" doesn't mean it doesn't hold an ARP table of some sort... it just means it cannot be configured by the user... and doesn't have the configurability for complex networks (i.e. VLAN's, STP, etc)

dustinmurphy

binaryhat wrote: »

Hmmm...stuck on that one...

Well...an unmanaged switch means the ports are on same VLAN so that's not the answer...

Port is being blocked??

I think that question at the end of his post is more of a rhetorical question. I think he's saying that the addressing and payload are in the frame, so why would it not be able to communicate?

IMO - the thing you're missing is ARP.