Quotas for your transit gateways - Amazon Virtual Private Cloud

Quotas for your transit gateways

Your AWS account has the following service quotas (previously referred to as quotas) related to transit gateways. Unless indicated otherwise, you can request an increase for a quota. For more information about service quotas, see AWS Service Quotas in the Amazon Web Services General Reference.

General

Routing

  • Number of transit gateway route tables per transit gateway: 20

  • Number of routes per transit gateway: 10,000

    For VPC route table quotas, see Amazon VPC quotas in the Amazon VPC User Guide.

  • Dynamic routes advertised from a virtual router appliance to a Transit Gateway Connect peer: 1,000

  • Routes advertised from a Transit Gateway Connect peer on a transit gateway to a virtual router appliance: 5,000

    Advertised routes come from the route table that's associated with the Connect attachment.

  • Number of static route for a prefix to a single attachment: 1

Transit gateway attachments

  • Total number of transit gateway attachments per transit gateway: 5,000

  • Number of unique transit gateway attachments per VPC: 5

    This value cannot be increased. A transit gateway cannot have more than one attachment to the same VPC.

  • Number of transit gateway peering attachments per transit gateway: 50

  • Number of transit gateway peering attachments between two transit gateways: 1

  • Number of pending transit gateway peering attachments per transit gateway: 10

  • Number of Transit Gateway Connect peers (GRE tunnels) per transit gateway Connect attachment: 4

    This value cannot be increased.

Bandwidth

  • Maximum bandwidth (burst) per VPC, Direct Connect gateway, or peered transit gateway connection: 50 Gbps

  • Maximum bandwidth per VPN tunnel: 1.25 Gbps

    This is a hard value. You can use ECMP to get higher VPN bandwidth by aggregating multiple VPN tunnels. To use ECMP, the VPN connection must be configured for dynamic routing. ECMP is not supported on VPN connections that use static routing.

  • Maximum bandwidth (burst) per Transit Gateway Connect peer (GRE tunnel) per Connect attachment: 5 Gbps

    This is a hard value. You can create up to 4 Transit Gateway Connect peers per Connect attachment (up to 20 Gbps in total bandwidth per Connect attachment), as long as the underlying transport (VPC or AWS Direct Connect) attachment supports the required bandwidth. You can use equal-cost multi-path routing (ECMP) to get higher bandwidth by scaling horizontally across multiple Transit Gateway Connect peers of the same Connect attachment or across multiple Connect attachments on the same transit gateway. The transit gateway cannot use ECMP between the BGP peerings of the same Transit Gateway Connect peer.

AWS Direct Connect gateways

  • Number of AWS Direct Connect gateways per transit gateway: 20

    This value cannot be increased.

  • Transit gateways per AWS Direct Connect gateway: 3

    This value cannot be increased.

MTU

  • The maximum transmission unit (MTU) of a network connection is the size, in bytes, of the largest permissible packet that can be passed over the connection. The larger the MTU of a connection, the more data that can be passed in a single packet. A transit gateway supports an MTU of 8500 bytes for traffic between VPCs, Direct Connect gateway and peering attachments. Traffic over VPN connections can have an MTU of 1500 bytes.

  • Packets with a size larger than 8500 bytes that arrive at the transit gateway are dropped.

  • The transit gateway does not generate the FRAG_NEEDED for ICMPv4 packet, or the Packet Too Big (PTB) for ICMPv6 packet. Therefore, the Path MTU Discovery (PMTUD) is not supported.

  • The transit gateway enforces Maximum Segment Size (MSS) clamping for all packets. For more information, see RFC879.

Multicast

  • Number of multicast domains per transit gateway: 20

  • Number of multicast group members and sources per transit gateway: 1000

  • Number of multicast group members per transit gateway multicast group: 100

  • Number of multicast domain associations per VPC: 20

  • Number of sources per transit gateway multicast group: 1

  • Number of static multicast group and IGMPv2 multicast group members and sources per transit gateway: 10,000

  • Number of static multicast group and IGMPv2 multicast group members per transit gateway multicast group: 100

  • Maximum multicast throughput per flow: 1 Gbps

  • Maximum aggregate multicast throughput per subnet: 4 Gbps

  • Maximum aggregate multicast throughput per subnet including unicast traffic: 50 Gbps

Additional quota resources

For information about quotas that apply to Site-to-Site VPN connections, see Site-to-Site VPN Quotas in the AWS Site-to-Site VPN User Guide.

For information about quotas that apply to VPC attachments, see Amazon VPC Quotas in the Amazon VPC User Guide.

For information about quotas that apply to Direct Connect gateway attachments, see AWS Direct Connect Quotas in the AWS Direct Connect User Guide.

For more information about service quotas for Transit Gateway Network Manager, see Network Manager quotas.