Does AWS Transit Gateway peering supports Jumbo frames (MTU)?

Question

I am not able to find any reference for TGW Peering Jumbo MTU support, can you please confirm if this is supported?

I can see in the VPC docs, that inter-region VPC peering doesn't support Jumbo frames, since TGW Peering also uses the same architecture (I believe) it should also not support Jumbo MTU.

I tried a test (EC2 to EC2 across TGW Peering with DF bit set) and it works up to 8500 MTU. Apologies if I am missing something very obvious here.

```
h-4.2$ ping -M do -s 8472 10.2.1.167.  
PING 10.2.1.167 (10.2.1.167) 8472(8500) bytes of data.  
8480 bytes from 10.2.1.167: icmp_seq=1 ttl=253 time=73.3 ms.  
8480 bytes from 10.2.1.167: icmp_seq=2 ttl=253 time=72.4 ms.  
8480 bytes from 10.2.1.167: icmp_seq=3 ttl=253 time=72.5 ms.  
8480 bytes from 10.2.1.167: icmp_seq=4 ttl=253 time=72.3 ms.  
^C.   
--- 10.2.1.167 ping statistics ---  
4 packets transmitted, 4 received, 0% packet loss, time 3005ms.
```

Accepted Answer

TGW does support Jumbo MTU (although at 8500) for all attachments except VPN. See below link:
https://docs.aws.amazon.com/vpc/latest/tgw/what-is-transit-gateway.html

*"Transit Gateway Maximum Transmission Unit (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 can be passed in a single packet. A transit gateway supports an MTU of **8500 bytes** for traffic between VPCs, Direct Connect and **peering attachments**. Traffic over VPN connections can have an MTU of 1500 bytes."*

Does AWS Transit Gateway peering supports Jumbo frames (MTU)?

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