Why Traffic Forwarding Fails When Interfaces on the 1E1T1-M/2E1T1-M/1E1T1-F/2E1T1-F Interface Cards Are Added to an MP-Group and the Maximum MTU of the Interfaces Is Set to 1596 Bytes
After interfaces on the 1E1T1-M/2E1T1-M/1E1T1-F/2E1T1-F interface cards are added to an MP-Group, the interfaces add a 4-byte MP packet header to a 1596-byte IP packet before sending it. As a result, the total packet length exceeds the maximum MTU of the interfaces, 1596 bytes. Consequently, traffic forwarding fails.
In this scenario, you are advised to set the MTU of the interfaces on the 1E1T1-M/2E1T1-M/1E1T1-F/2E1T1-F interface cards to 1592 bytes.