A technician is troubleshooting host connectivity issues on the switches. The hosts in VLANs 10 and 15 on Sw11 are unable to communicate with hosts in the same VLANs on Sw12. Hosts in the Admin VLAN are able to communicate. The port-to-VLAN assignments are identical on the two switches. What could be the problem?
A. The Fa0/1 port is not operational on one of the switches. B. The link connecting the switches has not been configured as a trunk. C. At least one port needs to be configured in VLAN 1 for VLANs 10 and 15 to be able to communicate. D. Port FastEthernet 0/1 needs to be configured as an access link on both switches. E. A router is required for hosts on SW11 in VLANs 10 and 15 to communicate with hosts in the same VLAN on Sw12.
Correct Answer: B
In order for hosts in the same VLAN to communicate with each other over multiple switches, those switches need to be configured as trunks on their connected interfaces so that they can pass traffic from multiple VLANs.
Given this output for Switch C, what should the network administrator’s next action be?
A. Check the trunk encapsulation mode for Switch C’s fa0/1 port. B. Check the duplex mode for Switch C’s fa0/1 port. C. Check the duplex mode for Switch A’s fa0/2 port. D. Check the trunk encapsulation mode for Switch A’s fa0/2 port.
Correct Answer: C
Here we can see that this port is configured for full duplex, so the next step would be to check the duplex setting of the port on the other switch. A mismatched trunk encapsulation would not result in input errors and CRC errors.
If the EtherChannel was configured with mode “auto”, it was using PAgP, so, we need to configure the other switch with “desirable” mode.
PAgP modes: auto | Desirable
LACP modes: active | pasive