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Troubleshooting VLANs


I'm studying VLANs and I have a doubt.

I'm in the following scenario:

I have three PC: PCA, PCB, PCC and each of them belong at differents VLANs and they are connected to a switch on three separated FastEthernet ports. The switch is connected to a router which is useful to connect PC1, PC2, PC3 (router on a stick). PCB can ping PCA and PCC, but can't telnet to the switch.

The correct answer of this multiple choice is: The switch needs an appropriate default gateway assigned.

My question is: If PCB can ping PCA and PCC why PCB can't telnet the switch? I think that if ping success it mean that ping leaves PCB, goes to he router and than go to PCA or PCC

I don't understand why PCB is not able to telnet to the switch from host B while ping can reach the others two hosts  successful

VIP Purple



If your on the same subnet it would work but the answer is correct if the switch has no default-gateway set how does it know to send traffic back to you on a different subnet

when everything is on the same subnet no need for gateway as it will arp the request anyway and be reachable but layer 2 devices without any gateway set will not get traffic out of its local broadcast domain

Pinging the switch is just the MGMT interface as its layer 2 it has nothing to do with the default-gateway and how traffic is sent back out , all switches at layer 2 would all have an ip in the same range for mgmt. purposes and reachability to make sure switch is up but that's al the ip is used for on layer 2 switch

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