A network administrator is investigating connectivity and performance problems on an 802.1Q trunk link connecting a distribution switch to a newly provisioned access switch. Syslog entries on the distribution switch repeatedly record %CDP-4-NATIVE_VLAN_MISMATCH alerts. Furthermore, interface status reports on the trunk link display a high count of late collisions and frame check sequence (FCS) errors on one side, alongside significant packet drops. Which TWO of the following root causes are responsible for these symptoms? (Select TWO.)
- A native VLAN configuration discrepancy exists between the trunk interfaces on the two switches.Cevap
- A duplex mismatch is present across the interconnected trunk switchports.Cevap
- CThe access switch has been configured with a higher numerical Bridge Protocol Data Unit (BPDU) priority value, forcing all trunk ports into a disabled state.
- DHosts on the same VLAN require an active Layer 3 default gateway to communicate across an 802.1Q trunk.
Cevap
The issues are caused by a native VLAN mismatch across the trunk link and a duplex mismatch on the trunk switchports.
The CDP syslog alert specifically diagnoses an 802.1Q native VLAN mismatch between the trunk peers. Simultaneously, late collisions accompanied by FCS frame errors are the classic diagnostic signatures of a duplex mismatch between connected interfaces.
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Anahtar Kavram
Identifying symptoms of native VLAN mismatches and duplex mismatches on trunk links