Currently, the following network diagnosis tools are available for VXLAN networks:
Ping and tracert commands of the switch can be used to perform a simple VRF-based connectivity check. Visible paths(1) Single-path detection: is used to detect the forwarding path of a single flow. It is generally used for fault diagnosis when traffic forwarding is abnormal.
(2) Multi-path detection: is used to detect all forwarding paths between two VTEPs. It is generally used to check network faults periodically and detect problems in advance.
Traffic statistics can be collected based on multiple dimensions to check whether the incoming and outgoing traffic is normal. Some debugging commands of a switch can be used to locate specific problems on the switch.Syslog and alarm functions: When an exception occurs, the switch records some syslogs or alarms, facilitating fault diagnosis
Troubleshooting procedures in several scenarios:
If the device status is incorrect due to incorrect configurations, check the following configurations:(1) BGP peer configuration and peer status
(2) Routing table
(3) ARP table
(4) Access-side configurations (including sub-interfaces, BDs, and BDIF interfaces)
The configurations are correct but service traffic is abnormal. The problem is more complex. Locate the device that discards packets first, and check whether the device is faulty.(1) Detect the packet loss location based on path detection or traffic statistics.
(2) Check the items in scenario 1. If the problem persists, contact the maintenance personnel of the vendor.
Loop caused by the networking environment(1) Check the MAC address flapping alarm to locate the loop.
(2) Find out the cause of the loop, for example, a configuration error or bug.
(3)
When a VXLAN fault occurs, for example, no corresponding route is found or traffic fails to be forwarded, use the following methods to rectify the fault as soon as possible:
n If no corresponding route is found, check whether configurations are correct. If configurations are correct, reset the protocol that establishes the route, or delete and reconfigure the protocol. For example, run the reset ospf peer command.
n If traffic fails to be forwarded, check whether configurations are correct and find the device that fails to forward traffic. Check whether routes and ARP entries on the problematic device are abnormal.
n If the fault persists, delete all VXLAN-related configurations and then deliver the configurations again.
n If the fault persists, reset the card or restart the device.
