Configuring the Interface Speed
You can configure the interface speed on the following interfaces:
- Configuring the Speed of Management Ethernet Interfaces on M Series and T Series Routers
- Configuring the Speed of Gigabit Ethernet Interfaces on J Series Routers
- Configuring the Speed of Fast Ethernet Interfaces
- Configuring the Speed of Tri-Rate Ethernet Copper Interfaces
- Configuring the Speed of SONET/SDH Interfaces
Configuring the Speed of Management Ethernet Interfaces on M Series and T Series Routers
M Series routers, MX Series routers, T Series routers, and TX Series routers use one of two management Ethernet interface types, either em or fxp, dependent on the installed Routing Engine model. For information about management Ethernet interfaces and to determine the management Ethernet interface type for your router, see Understanding Management Ethernet Interfaces and Supported Routing Engines by Chassis.
By default, the M Series and T Series routers management Ethernet interface autonegotiates whether to operate at 10 megabits per second (Mbps) or 100 Mbps. All other interfaces automatically choose the correct speed based on the PIC type and whether the PIC is configured to operate in multiplexed mode (using the no-concatenate statement in the [edit chassis] configuration hierarchy, as described in the Junos OS Administration Library for Routing Devices).
To configure the management Ethernet interface to operate at 10 Mbps or 100 Mbps, include the speed statement at the [edit interfaces fxp0] or [edit interfaces em0] hierarchy level:
For information about configuring the link mode, see Configuring the Link Characteristics on Ethernet Interfaces.
Configuring the Speed of Gigabit Ethernet Interfaces on J Series Routers
By default, Gigabit Ethernet interfaces (both built-in and PIMs) for J Series routers autonegotiate whether to operate at 10 megabits per second (Mbps), 100 Mbps, or 1000 Mbps.
To configure a J Series Gigabit Ethernet interface to operate at 10 Mbps, 100 Mbps, or 1000 Mbps, include the speed statement at the [edit interfaces ge-pim/0/port] hierarchy level:
For information about configuring the link mode, see Configuring the Link Characteristics on Ethernet Interfaces.
Configuring the Speed of Fast Ethernet Interfaces
By default, both of the built-in Fast Ethernet ports on the M7i router FIC autonegotiate whether to operate at 10 Mbps or 100 Mbps. All other interfaces automatically choose the correct speed based on the PIC type and whether the PIC is configured to operate in multiplexed mode (using the no-concatenate statement at the [edit chassis] hierarchy level, as described in the Junos OS Administration Library for Routing Devices).
If the link partner does not support autonegotiation, configure either Fast Ethernet port manually to match its link partner's speed and link mode. When the link mode is configured, autonegotiation is disabled.
![]() | Note: When you manually configure Fast Ethernet interfaces on the M Series and T Series routers, link mode and speed must both be configured. If both these values are not configured, the router uses autonegotiation for the link and ignores the user-configured settings. |
To configure a Fast Ethernet port on the FIC to operate at 10 Mbps or 100 Mbps, include the speed statement at the [edit interfaces fe-fpc/pic/port] hierarchy level:
For information about configuring the link mode, see Configuring the Link Characteristics on Ethernet Interfaces.
Configuring the Speed of Tri-Rate Ethernet Copper Interfaces
By default, the Tri-Rate Ethernet copper interfaces on MX Series routers operate at 1 Gbps. Tri-Rate Ethernet copper interfaces can also be configured to operate at 10 Mbps, 100 Mbps, or 1 Gbps.
![]() | Note: When you configure the Tri-Rate Ethernet copper interface to operate at 1 Gbps, autonegotiation must be enabled. |
![]() | Note: Half-duplex mode is not supported on Tri-Rate Ethernet copper interfaces. When you include the speed statement, you must include the link-mode full-duplex statement at the same hierarchy level. |
To configure a Tri-Rate Ethernet copper interface to operate at 10 Mbps, 100 Mbps, or 1 Gbps, include the speed statement at the [edit interfaces ge-fpc/pic/port] hierarchy level:
For information about configuring the link mode, see Configuring the Link Characteristics on Ethernet Interfaces.
Configuring the Speed of SONET/SDH Interfaces
You can configure the speed of SONET/SDH interfaces on next-generation SONET/SDH Type 1 and Type 2 PICs with SFP. The speed you select is dependent upon whether the PIC is in concatenated or nonconcatenated mode. In concatenated mode, the bandwidth of the interface is in a single channel. In nonconcatenated mode, the PIC operates in channelized (multiplexed) mode.
Table 1 shows the mode combinations for the next-generation SONET/SDH Type 1 PICs with SFP.
Table 1: Type 1 PIC Mode Combinations
PIC | Mode | Speed Configuration | Default Mode |
---|---|---|---|
2-port OC3 | 2xOC3 concatenated | fpc/pic/0 speed oc3 | concatenated |
4-port OC3 | 1xOC12 concatenated | fpc/pic/0 speed oc12 | — |
1xOC12 nonconcatenated | fpc/pic/0:0 speed oc3 | nonconcatenated | |
4xOC3 concatenated | fpc/pic/port speed oc3 | concatenated | |
1-port OC12 | 1xOC12 concatenated | fpc/pic/0 speed oc12 | concatenated |
1xOC12 nonconcatenated | fpc/pic/0:0 speed oc3 | nonconcatenated | |
1xOC3 concatenated | fpc/pic/0 speed oc3 | — |
Table 2 shows the mode combinations for the next-generation SONET/SDH Type 2 PICs with SFP.
Table 2: Type 2 PIC Mode Combinations
PIC | Mode | Speed Configuration | Default Mode |
---|---|---|---|
1-port OC48, IQ and IQE | 1xOC48 concatenated | fpc/pic/0 speed oc48 | concatenated |
1xOC48 nonconcatenated | fpc/pic/0:0 speed oc12 | nonconcatenated | |
1xOC12 concatenated | fpc/pic/0 speed oc12 | — | |
1xOC12 nonconcatenated | fpc/pic/0 0 speed oc3 | — | |
1xOC3 concatenated | fpc/pic/0 speed oc3 | — | |
4-port OC12, IQ and IQE | 1xOC48 concatenated | fpc/pic/0 speed oc48 | — |
1xOC48 nonconcatenated | fpc/pic/0:0 speed oc12 | nonconcatenated | |
1xOC12 nonconcatenated | fpc/pic/0 speed oc3 | — | |
4xOC12 concatenated | fpc/pic/port speed oc3|oc12 | concatenated | |
4-port OC3, IQ and IQE | 1xOC12 concatenated | fpc/pic/0 speed oc12 | — |
1xOC12 nonconcatenated | fpc/pic/0:0 speed oc3 | nonconcatenated | |
4xOC3 concatenated | fpc/pic/port speed oc3 | concatenated |
By default, SONET/SDH PICs operate in concatenated mode. To specify interface speed in concatenated mode, include the speed statement with options at the [edit interfaces so-fpc/pic/port] hierarchy level:
For example, each port of the 4-port OC12 PIC can be configured to be in OC3 or OC12 speed independently when this PIC is in 4xOC12 concatenated mode.
To specify interface speed in nonconcatenated mode, include the speed statement at the [edit interfaces so-fpc/pic/port.channel] hierarchy level:
To configure the PIC to operate in channelized (multiplexed) mode, include the no-concatenate statement at the [edit chassis fpc slot-number pic pic-number] hierarchy level.
For more information about using the no-concatenate statement, see the Junos OS Administration Library for Routing Devices.