Path MTU Discovery
Path MTU discovery allows the sender of IP packets to discover the Maximum Transmission Unit (MTU) of packets that it is sending to a given destination. The MTU is the largest packet that can be sent through the network along a path without requiring fragmentation. Previous releases supported ICMP to adjust the conduit MTU.
To overcome these limitations, Oracle SD-WAN Edge Release 2.4 introduces a new path MTU discovery method that will actively probe each sending path of each conduit to find out the current MTU, and adjust the conduit MTU accordingly. This feature must be enabled by the user and will then probe each path within a conduit every 10 minutes.
This feature can be configured in the Oracle SD-WAN Edge Configuration Editor (See Figure 12, below). Additionally, the Oracle SD-WAN Edge Web Console and CLI will display the current MTU that is being used by each WAN Ingress path on the conduit (See Figure 13 for an example) For more information on the Oracle SD-WAN Edge Configuration Editor, please see the APN Configuration Editor User's Guide. For more information on using the Oracle SD-WAN Edge Web Console, please refer to the APN Appliance Operation Guide.
Figure 12. Active MTU Discovery in the Oracle SD-WAN Edge Configuration Editor.
If editing the configuration file manually, the command options for this capability in the configuration file are enabled under the WAN link, conduit services:
|
add conduit_usage |
remote_site_name=Client-test1 wan_egress_rate_fair_share=100000 wan_ingress_rate_fair_share=100000 service_group_name=Default udp_port_num=2156 active_path_mtu_discovery_enable=true; |
For more information on the Oracle SD-WAN Edge configuration file, please see the APN Configuration Reference.