Troubleshooting the Grid Network MTU mismatch alert

The Grid Network MTU mismatch alert is triggered when the maximum transmission unit (MTU) setting for the Grid Network interface (eth0) differs significantly across nodes in the grid.

1. List the MTU settings for eth0 on all nodes.
   • Use the query provided in the Grid Manager.
   • Navigate to <primary Admin Node IP address>/metrics/graph and enter the following query: node_network_mtu_bytes{interface='eth0'}
2. Modify the MTU settings as necessary to ensure they are the same for the Grid Network interface (eth0) on all nodes.
   • For appliance nodes, see the installation and maintenance instructions for your appliance.
   • For Linux- and VMware-based nodes, use the following command: /usr/sbin/change-mtu.py [-h] [-n node] mtu network [network...]
     Example: change-mtu.py -n node 1500 grid admin

     Note: On Linux-based nodes, if the desired MTU value for the network in the container exceeds the value already configured on the host interface, you must first configure the host interface to have the desired MTU value, and then use the change-mtu.py script to change the MTU value of the network in the container.

     Use the following arguments for modifying the MTU on Linux- or VMware-based nodes.

     Positional arguments	Description
     mtu	The MTU to set. Must be in the range 1280 to 9216.
     network	The networks to apply the MTU to. Include one or more of the following network types: grid admin client
     Optional arguments	Description
     -h, – help	Show the help message and exit.
     -n node, --node node	The node. The default is the local node.