Symptoms:

When experiencing packet loss across ZVM connectivity link, the following issues might occur:
  1. Unable to pair sites.
  2. Site-to-site disconnection between a ZVM pair.
  3. Prolonged or unexpected Zerto sync operations (relevant for Self -replicating setup only?).
The following is a list of common packet loss causes:
  1. Link Congestion (an event where a network device has to discard old queue information before it is able to process it).
  2. Different network components and consumers (such as Zerto's VRAs) are using different MTU values on the same network.

Solution:

Possible solutions include (but are not limited to) the following:
  1. Verify that all Zerto components (VRA, ZVM etc) are configured with the correct MTU value
  2. Increase the bandwidth of the congested link(s)
  3. Implement Quality of Service (QoS) and set high priority to ZVM-related traffic
  4. Verify that all network equipment can handle your maximum throughput, or potentially cluster additional hardware to increase throughput