Title: Alarm for Edge global ARP table usage high. Event ID: edge_health.edge_global_arp_table_usage_high Alarm Description
Purpose: Indicates usage percentage of global ARP table.
Impact: Packets drops when number of ARP entries reaches maximum.
Environment
VMware NSX-T Data Center
Edge Form factors:
Bare Metal Edge
VM Edge
Cause
Alarm is raised when the ARP table is full and no new entries can be added any more.
Resolution
Steps to resolve For 3.0.0 and higher
Recommenced Action :
Consider increasing the ARP table size if it is lesser that default size (50000) which is also the maximum allowed size.
If the ARP table size is set to the maximum value (50000), try segmenting the IP address range belonging to the Logical router into multiple Logical routers
If the above steps don't resolve the alarm, check if the Edge node is compromised.
Steps to increase the ARP limit:
Identify if router on which alarm is raised is Tier-0 or Tier-1
Get the Tier0/Tier1 message body using GET Policy API
Tier-0: GET https://<NSX Manager IP>/policy/api/v1/infra/tier-0s/<tier-0 name>
Tier-1: GET https://<NSX Manager IP>/policy/api/v1/infra/tier-1s/<tier-1 name>
Add the arp_limit attribute if not present in the response or Update the arp_limit attribute if present
Using the updated response payload as body and PATCH Tier-0/Tier-1