DawgTalkers.net Forums DawgTalk Tailgate Forum Any networking(switching) experts here?

I'm probably missing something obvious here, I figure I'll toss this out and see if anyone can explain where I went wrong.

Here's the network layout I am looking at.

I have N0 and N1 connected to a switch, N2 and N3 connected to another switch and the 2 switches connected to a router. If N0 has a misconfigured ip address, it won't be able to communicate with N2 and N3, but it should still be able to communicate with N1, right? Since N0 and N1 are plugged into the switch, the switch will use the mac-address table to find the other machine, right?

Lets say:
router port Ethernet0 has 192.168.10.1 /24
N0 is 192.168.20.1 /24
N1 is 192.168.10.2 /24

My thinking is N0 and N1 would still be able to communicate through the switch, any traffic wouldn't even make it to the router.

I had a question on a practice exam(ccna) that stated N0 would not be able to communicate with any host. I'm just trying to figure out why, since a switch communicates at layer 2, and it's a layer 3 address that's messed up. Any thoughts?

Quote:

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Since N0 and N1 are plugged into the switch, the switch will use the mac-address table to find the other machine, right?

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While that sounds feasible, it would be highly dependent upon the switch's capabilities, but my initial guess is no, they won't still talk.

you are still using tcp/ip to 'communicate' between devices, whether they are on the same switch or not....and to do that they will have to know how to route to the ip address...even though the 2 devices are on the same switch, they must still talk to the router to figure out how to route to the other's ip address...

you are right in thinking switches communicate at layer 2 (DL) but routing is a layer 3 function..if you have 2 PC's on different subnets they will not communicate unless 1. The switch is multilayer or 2. you are using vlans with router on stick. the way your diagram is reading, they want you to assume the switches can't do layer 3 because they provide a router.I can tell you Cisco loves to get tricky with the wording and diagrams...later on in your studied in cisco, you'll see they will get model and IOS specific in the questions and diagrams..i took the 801 CCNA,(old one) and then the CCNP, and i've passed the CCIE written, but the lab kicked my behind..i didn't do terrible considering the fail rate, but i didn't pass in 2 attempts so far..lol, my problem was finding rack time. If you want some good resources to help you prep, PM me and i can point you to a bunch

Ok, I think I got it. If the hosts on are the same subnet, they don't need the router and can communicate directly through the switch. But since N0 is misconfigured with a ip on a different subnet, it will need a router, but because the ip address is wrong it won't be able to communicate with the router, therefore it won't be able to communicate with any host. Right?

I feel like this should be simple to understand but it's just not fitting together. I keep thinking that if N0 sends something to NC1, the switch will look up the mac address and send it out the port for N1 and that's it.