Chapter 32. Using LLDP to debug network configuration problems
Chapter 32. Using LLDP to debug network configuration problems You can use the Link Layer Discovery Protocol (LLDP) to debug network configuration problems in the topology. This means that, LLDP can report configuration inconsistencies with other hosts or routers and switches. 32.1. Debugging an incorrect VLAN configuration using LLDP information If you configured a switch port to use a certain VLAN and a host does not receive these VLAN packets, you can use the Link Layer Discovery Protocol (LLDP) to debug the problem. Perform this procedure on the host that does not receive the packets. Prerequisites The nmstate package is installed. The switch supports LLDP. LLDP is enabled on neighbor devices. Procedure Create the ~/enable-LLDP-enp1s0.yml file with the following content: interfaces: - name: enp1s0 type: ethernet lldp: enabled: true Use the ~/enable-LLDP-enp1s0.yml file to enable LLDP on interface enp1s0 : Display the LLDP information: Verify the output to ensure that the settings match your expected configuration. For example, the LLDP information of the interface connected to the switch shows that the switch port this host is connected to uses VLAN ID 448 : - type: 127 ieee-802-1-vlans: - name: v2-0488-03-0505 vid: 488 If the network configuration of the enp1s0 interface uses a different VLAN ID, change it accordingly. Additional resources Configuring VLAN tagging
interfaces: - name: enp1s0 type: ethernet lldp: enabled: true nmstatectl apply ~/enable-LLDP-enp1s0.yml nmstatectl show enp1s0 - name: enp1s0 type: ethernet state: up ipv4: enabled: false dhcp: false ipv6: enabled: false autoconf: false dhcp: false lldp: enabled: true neighbors: - - type: 5 system-name: Summit300-48 - type: 6 system-description: Summit300-48 - Version 7.4e.1 (Build 5) 05/27/05 04:53:11 - type: 7 system-capabilities: - MAC Bridge component - Router - type: 1 _description: MAC address chassis-id: 00:01:30:F9:AD:A0 chassis-id-type: 4 - type: 2 _description: Interface name port-id: 1/1 port-id-type: 5 - type: 127 ieee-802-1-vlans: - name: v2-0488-03-0505 vid: 488 oui: 00:80:c2 subtype: 3 - type: 127 ieee-802-3-mac-phy-conf: autoneg: true operational-mau-type: 16 pmd-autoneg-cap: 27648 oui: 00:12:0f subtype: 1 - type: 127 ieee-802-1-ppvids: - 0 oui: 00:80:c2 subtype: 2 - type: 8 management-addresses: - address: 00:01:30:F9:AD:A0 address-subtype: MAC interface-number: 1001 interface-number-subtype: 2 - type: 127 ieee-802-3-max-frame-size: 1522 oui: 00:12:0f subtype: 4 mac-address: 82:75:BE:6F:8C:7A mtu: 1500 - type: 127 ieee-802-1-vlans: - name: v2-0488-03-0505 vid: 488