Mtu Configuration Guidelines; Table 4: Mtu Default Values - Alcatel-Lucent 7210 SAS E OS Configuration Manual

802.3ah OAM

MTU Configuration Guidelines

Observe the following general rules when planning your physical MTU configurations:
The 7210 SAS must contend with MTU limitations at many service points. The physical (access
and access uplink) port, MTU values must be individually defined.
•
•
•
Default MTU Values
Table 4
encapsulation.

Table 4: MTU Default Values

Ethernet
Ethernet
Fast Ethernet
Other Ethernet
*The default MTU for Ethernet ports other than Fast Ethernet is actually the lesser of 9212 and
any MTU limitations imposed by hardware which is typically 9728 bytes.
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Identify the ports that are designated as access uplink ports as these are intended to carry
service traffic.
MTU values should not be modified frequently.
MTU values must conform to the following conditions:
→ The access uplink port MTU must be greater than or equal to the access port MTU
plus the overhead added by the system (for example, typically 4 bytes of VLAN tag
are added when a packet is transmitted using the QinQ access uplink).
displays the default MTU values which are dependent upon the (sub-) port type, mode, and
Port Type Mode
access
access
uplink
uplink
7210 SAS E Interface Configuration Guide
Encap Type Default
(bytes)
null 1514
dot1q 1518
— 1522
— 9212*