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Instances Limits

Validated on 23 Aug 2023 - Last edited on 23 Aug 2023

FibaCloud Instances are Linux-based virtual machines (VMs) running on virtualized hardware. Every Instance you create is a new server that you can use independently or as part of a larger, cloud-based infrastructure.


  • Some Instance network traffic is restricted to help prevent malicious actions, like reflected DDoS attacks. We know these restrictions also prevent functionality like configuring direct server return and using Instances as routers and site-to-site VPN gateways. Future changes to our network will support this functionality. Until then, some workarounds include using a VPN mesh network or overlay network.

    The following types of traffic are restricted:

    • TCP and UDP traffic on port 11211 inbound from external networks (due to the Memcached amplification attacks).
    • Multicast traffic.
    • Traffic not matching a Instances IP address/MAC address.
    • SMTP via Reserved IPs and IPv6.
  • Dedicated CPU Instances with Premium CPUs have a network throughput limit of 10 Gbps. All other Instances have a maximum network throughput limit of 2 Gbps.

  • SMTP port 25 is blocked on all Instances for new accounts. As an alternative, we recommend using a dedicated email deliverability platform, like SendGrid, and generally recommend against running your own mail server.