Description
This article explains how to set the correct MTU for UniFi service. UniFi is a triple-play service by Telekom Malaysia, offering Internet access, VoIP, and IPTV to residential and business customers in Malaysia.
Scope
FortiGate, Unifi’s internet access.
Solution
Users might have an issue connecting to PPPoE if the correct MTU is not specified. Apart from Vthe LAN interface with VLAN-id 500 using PPPoE Dialer, this interface also requires MTU to be set to 1492.
config system interface
edit "unifi"
set mtu-override enable -> Enable MTU override
set mtu 1492 -> set MTU to 1492
next
end
When configuring an MTU of 1492 for PPPoE, an 8-byte PPPoE header is added to the standard Ethernet frame. This results in an effective MTU of 1500 bytes.
To verify the configured MTU, use the following command:
diagnose netlink interface list unifi
