Junos® OS Ethernet Interfaces Configuration ... - Juniper Networks

auto-negotiation
Syntax (auto-negotiation | no-auto-negotiation) ;
Hierarchy Level [edit interfaces interface-name ether-options],
[edit interfaces interface-name gigether-options],
[edit interfaces ge-pim/0/0 switch-options switch-port port-number]
Release Information Statement introduced in Junos OS Release 7.6.
Statement introduced in Junos OS Release 8.4 for J Series Services Routers.
Statement introduced in Junos OS Release 9.0 for EX Series switches.
Statement introduced in Junos OS Release 12.2 for ACX Series Universal Access Routers.
Description For Gigabit Ethernet interfaces on M Series, MX Series, T Series, TX Matrix routers, and
Copyright © 2012, Juniper Networks, Inc.
ACX Series routers explicitly enable autonegotiation and remote fault. For EX Series
switches and J Series Services Routers, explicitly enable autonegotiation only.
• auto-negotiation—Enables autonegotiation. This is the default.
• no-auto-negotiation—Disable autonegotiation. When autonegotiation is disabled, you
must explicitly configure the link mode and speed.
When you configure Tri-Rate Ethernet copper interfaces to operate at 1 Gbps,
autonegotiation must be enabled.
NOTE: On EX Series switches, an interface configuration that disables
autonegotiation and manually sets the link speed to 1 Gbps is accepted when
you commit the configuration; however, if the interface you are configuring
is a Tri-Rate Ethernet copper interface, the configuration is ignored as invalid
and autonegotiation is enabled by default.
To correct the invalid configuration and disable autonegotiation:
1. Delete the no-auto-negotiation statement and commit the configuration.
2. Set the link speed to 10 or 100 Mbps, set no-auto-negotiation, and commit
the configuration.
Chapter 34: Summary of Ethernet Interfaces Configuration Statements
On J Series Services Routers with universal Physical Interface Modules (uPIMs) and on
EX Series switches, if the link speed and duplex mode are also configured, the interfaces
use the values configured as the desired values in the negotiation. If autonegotiation is
disabled, the link speed and link mode must be configured.
NOTE: On T4000 routers, the auto-negotiation command is ignored for
interfaces other than Gigabit Ethernet.
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