A network engineer receives an security alert regarding an unexpected network device connected to interface GigabitEthernet1/0/5 on a Cisco switch. To inspect the neighboring device details via Link Layer Discovery Protocol (LLDP), the engineer executes the `show lldp entry Switch-B` command and receives the following output:
Capability codes:
(R) Router, (B) Bridge, (T) Telephone, (W) WLAN Access Point, (P) Repeater
Local Intf: Gi1/0/5
Chassis id: 0026.99a1.b2c0
Port id: Gi0/1
Port Description: Uplink-to-Core
System Name: Switch-B
System Capabilities: B, R
Enabled Capabilities: B
Management Addresses:
IP: 192.168.10.50
Based on this command output, which statement accurately describes the remote neighbor device?
- The remote device is identified as Switch-B, connected via its own GigabitEthernet0/1 interface, and is currently operating with Layer 2 bridging capability enabled.Answer
- BThe local switch receives LLDP messages on interface GigabitEthernet0/1 from the remote device's local port GigabitEthernet1/0/5.
- CThe remote device is actively routing IP packets across subnets because both Router (R) and Bridge (B) system capabilities are listed.
- DThe remote device is transmitting Cisco Discovery Protocol (CDP) Type-Length-Value (TLV) attributes to advertise management address 192.168.10.50.
Answer
The remote device is identified as Switch-B, connected via its own GigabitEthernet0/1 interface, and is currently operating with Layer 2 bridging capability enabled.
The correct answer accurately interprets the LLDP entry output fields: 'System Name: Switch-B' identifies the neighbor hostname, 'Port id: Gi0/1' specifies the remote interface, and 'Enabled Capabilities: B' confirms the neighbor is currently functioning as a Layer 2 bridge/switch.
Step-by-Step Solution
Key Concept
Interpretation of LLDP neighbor entry outputs, distinguishing local vs. remote interfaces and system vs. enabled capabilities.