Agents in different VPCs might experience problems when trying to communicate with Deep Security Manager. This could be because the network maximum transmission unit (MTU) supported by Amazon Web Services is 1500 and Deep Security Agent communication traffic can exceed this, which results in fragmented and dropped packets.

You can prevent this MTU-related communication issue from happening by adding a new firewall rule to all firewall policies. The key settings for this new firewall rule are shown in the image below.