Alcatel-Lucent 6850-48 参考指南
Virtual Private LAN Service (VPLS) Commands
OmniSwitch CLI Reference Guide
September 2009
page 26-39
configure service vpls service-mtu
Configures the administrative Maximum Transmission Unit (MTU) value for the specified Virtual Private
LAN Service (VPLS). This value specifies the largest frame size that the VPLS can transmit to the far-end
router without dropping packets or requiring IP fragmentation.
LAN Service (VPLS). This value specifies the largest frame size that the VPLS can transmit to the far-end
router without dropping packets or requiring IP fragmentation.
configure service vpls service-ip [customer customer-id] service-mtu bytes
configure service vpls service-ip [customer customer-id] no service-mtu
Syntax Definitions
service-id
An existing VPLS ID number.
customer-id
Optional. A customer ID number associated with the specified service
ID number.
ID number.
bytes
The largest service frame size, in bytes, allowed through this service.
The valid range is 1–9194.
The valid range is 1–9194.
Defaults
By default, the service MTU for VPLS is set to 1514.
Platforms Supported
OmniSwitch 9000E
Usage Guidelines
• Use the no form of this command to revert the service MTU to the default value.
• Specifying the customer ID associated with this VPLS is not required when using this command.
However, if the customer ID specified is not the one associated with the VPLS, the command is not
allowed.
allowed.
• The service MTU and the service delineation encapsulation overhead (for example., 4 bytes for a
802.1Q tag) of the SAP is used to derive the required MTU of the physical port or channel on which
the SAP was created. If the required payload is larger than the port or channel MTU, then the SAP is
placed in an inoperative state. If the required MTU is equal to or less than the port or channel MTU,
the SAP is able to transition to an operative state.
the SAP was created. If the required payload is larger than the port or channel MTU, then the SAP is
placed in an inoperative state. If the required MTU is equal to or less than the port or channel MTU,
the SAP is able to transition to an operative state.
• When binding an SDP to a service, the service MTU is compared to the path MTU associated with the
SDP. The path MTU is dynamically reduced due to the MTU capabilities discovered by the tunneling
mechanism of the SDP or the egress interface MTU capabilities based on the next hop in the tunnel
path.
mechanism of the SDP or the egress interface MTU capabilities based on the next hop in the tunnel
path.
• If the service MTU is larger than the path MTU, the SDP binding for the service is placed in an inoper-
ative state. If the service MTU is equal to or less than the path MTU, then the SDP binding is placed in
an operational state.
an operational state.