Supported Platforms
Related Documentation
auto-negotiation
Syntax
Hierarchy Level
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 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:
|
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. |
Default
Autonegotiation is automatically enabled. No explicit action is taken after the autonegotiation is complete or if the negotiation fails.
Options
remote-fault (local-interface-online | local-interface-offline)—(Optional) For M Series, MX Series, T Series, TX Matrix routers, and ACX Series routers only, manually configure remote fault on an interface.
Default: local-interface-online
Required Privilege Level
interface—To view this statement in the configuration.
interface-control—To add this statement to the configuration.
