Support for Jumbo Frames in Avi Vantage


This guide explains the support for jumbo frames in Avi Vantage.

Avi Vantage supports MTU greater than 1500 on the Service Engine interface. However, PMTU discovery is not supported. Ensure that the larger MTU is supported throughout the network.

Configuring SE MTU

You can manually configure to allow jumbo frames in the datapath using Service Engine property se_mtu. After configuring manually, the range will be a user configured value between 512-9000 and will not have any default value.

The global MTU is an SE property used to limit the MTU if there are some encapsulation overheads that can enlarge the packet over the original MTU. Starting with Avi Vantage version 18.2.8, you can replace the global MTU with se_mtu for the same purpose.

The se_mtu always overrides global MTU if configured. For instance, if you configure se_mtu to 9K, then the system does not depend on global MTU value. Global MTU is kept only for backward compatibility, i.e., if you configure global MTU in an earlier release and do an upgrade, then the global MTU should still take effect unless you configure se_mtu later.

You can configure se_mtu with jumbo size on the serviceenginegroup. This will change the MTU to the value for all the VNICs on all the SEs in the Service Engine group. If it is not set, then it will be backward compatible with global_mtu of Service Engine properties.

You need to set all the VNIC’s MTU to global_mtu command if it has been configured or to VNIC’s original MTU if it is not configured.

Note: The se_mtu affects the MTU of the SE’s interfaces only.

Ensure that the jumbo MTU is configured on all the nodes along the data path for the end-to-end jumbo frame traffic to work. The configuration should be accurate for the results to be as expected.

Configuration Example

[admin:10-79-109-168]: > configure serviceenginegroup Default-Group

[admin:10-79-109-168]: serviceenginegroup> se_mtu 9000

[admin:10-79-109-168]: serviceenginegroup> save