Command Line Reference Guide

Interfaces | 563
Example
The VLAN contains tagged members with Link MTU of 1522 and IP MTU of 1500 and untagged
members with Link MTU of 1518 and IP MTU of 1500. The VLAN’s Link MTU cannot be higher
than 1518 bytes and its IP MTU cannot be higher than 1500 bytes .
negotiation auto
c e s
Enable auto-negotiation on an interface.
Syntax
negotiation auto
To disable auto-negotiation, enter no negotiation auto.
Defaults
Enabled.
Command Modes
INTERFACE
Command
History
Usage
Information
This command is supported on C-Series, S-Series, and E-Series (TeraScale and ExaScale) 10/100/1000
Base-T Ethernet interfaces.
The no negotiation auto command is only available if you first manually set the speed of a port to
10Mbits or 100Mbits.
The negotiation auto command provides a mode option for configuring an individual port to
forced-master/forced slave once auto-negotiation is enabled.
Example 1
(Negotiation)
FTOS(conf)# int gi 0/0
FTOS(conf-if)# neg auto
FTOS(conf-if-autoneg)# ?
end Exit from configuration mode
exit Exit from autoneg configuration mode
mode Specify autoneg mode
no Negate a command or set its defaults
show Show autoneg configuration information
FTOS(conf-if-autoneg)#mode ?
forced-master Force port to master mode
forced-slave Force port to slave mode
Table 25-43. Difference between Link MTU and IP MTU
Layer 2 Overhead Link MTU and IP MTU Delta
Ethernet (untagged) 18 bytes
VLAN Tag 22 bytes
Untagged Packet with VLAN-Stack Header 22 bytes
Tagged Packet with VLAN-Stack Header 26 bytes
Version 8.1.1.0 Introduced on E-Series ExaScale
Version 7.6.1.0 Introduced on S-Series
Version 7.5.1.0 Introduced on C-Series
pre-Version 6.2.1.0 Introduced for E-Series
Note: The mode option is not available on non-10/100/1000 Base-T Ethernet line cards.