Physical Interface Properties
The physical interfaces undergo various transitions which is advertised to the Junos OS for proper functioning of the routers and switches. Accounting profiles that specify the characteristics of data about the traffic passing through the routers and switches can also be configured on the physical interfaces. Simple Network Management Protocol (SNMP) notifications can be enabled on the physical interface to provide information about the state of an interface or when a connection changes. The interface offers to configure various modes like short-reach-mode, flow-control and media type on the devices for ease of access.
Damping Shorter Physical Interface Transitions
By default, when an interface changes from being up to being down, or from down to up, this transition is advertised immediately to the hardware and Junos OS. In some situations—for example, when an interface is connected to an add/drop multiplexer (ADM) or wavelength-division multiplexer (WDM), or to protect against SONET/SDH framer holes—you might want to damp interface transitions. This means not advertising the interface’s transition until a certain period of time has passed, called the hold-time. When you have damped interface transitions and the interface goes from up to down, the down hold-time timer is triggered. Every interface transition that occurs during the hold-time is ignored. When the timer expires and the interface state is still down, then the router begins to advertise the interface as being down. Similarly, when an interface goes from down to up, the up hold-time timer is triggered. Every interface transition that occurs during the hold-time is ignored. When the timer expires and the interface state is still up, then the router begins to advertise the interface as being up. For information about physical interface damping, see Physical Interface Damping Overview.
This task applies to damping shorter physical interface transitions in milliseconds. To damp longer physical interface transitions in seconds, see Damping Longer Physical Interface Transitions.
To configure damping of shorter physical interface transitions:
The hold time can be a value from 0 through 4,294,967,295 milliseconds. The default value is 0, which means that interface transitions are not damped. Junos OS advertises the transition within 100 milliseconds of the time value you specify.
For most Ethernet interfaces, hold timers are implemented using a one-second polling algorithm. For 1-port, 2-port, and 4-port Gigabit Ethernet interfaces with small form-factor pluggable transceivers (SFPs), hold timers are interrupt-driven.
The hold-time
option is not available for controller
interfaces.
See Also
Configuring Accounting for the Physical Interface
- Accounting Profiles Overview
- Configuring Accounting for the Physical Interface
- Displaying Accounting Profile for the Physical Interface
Accounting Profiles Overview
Juniper Networks routers and switches can collect various kinds of data about traffic passing through the router and switch. You can set up one or more accounting profiles that specify some common characteristics of this data, including the following:
The fields used in the accounting records
The number of files that the router or switch retains before discarding, and the number of bytes per file
The polling period that the system uses to record the data
You configure the profiles and define a unique name for each
profile using statements at the [edit accounting-options]
hierarchy level. There are two types of accounting profiles: interface
profiles and filter profiles. You configure interface profiles by
including the interface-profile
statement at the [edit
accounting-options]
hierarchy level. You configure filter profiles
by including the filter-profile
statement at the [edit
accounting-options]
hierarchy level. For more information, see
the Junos OS Network Management Administration Guide for Routing Devices.
You apply filter profiles by including the accounting-profile
statement at the [edit firewall filter filter-name]
and [edit firewall family family filter filter-name]
hierarchy levels. For more information, see the Routing Policies, Firewall Filters, and Traffic Policers User Guide.
Configuring Accounting for the Physical Interface
Before you begin
You must configure a profile to collect error and statistic information for input and output packets on a particular physical interface. An accounting profile specifies what statistics should be collected and written to a log file. For more information on how to configure an accounting-data log file, see the Configuring Accounting-Data Log Files.
An interface profile specifies the information collected and written to a log file. You can configure a profile to collect error and statistic information for input and output packets on a particular physical interface.
See Also
Displaying Accounting Profile for the Physical Interface
Purpose
To display the configured accounting profile a particular
physical interface at the [edit accounting-options interface-profile profile-name]
hierarchy level:
interface-name—ge-1/0/1
Interface profile —
if_profile
File name—
if_stats
Interval—15 minutes
Action
Run the
show
command at the[edit edit interfaces ge-1/0/1]
hierarchy level.[edit interfaces ge-1/0/1] accounting-profile if_profile;
Run the
show
command at the[edit accounting-options]
hierarchy level.interface-profile if_profile { interval 15; file if_stats { fields { input-bytes; output-bytes; input-packets; output-packets; input-errors; output-errors; } } }
Meaning
The configured accounting and its associated set options are displayed as expected.
Enabling or Disabling SNMP Notifications on Physical Interfaces
By default, Simple Network Management Protocol (SNMP) notifications are sent when the state of an interface or a connection changes. You can enable or disable these notification based on you requirements.
To explicitly enable sending SNMP notifications on the physical interface, perform the following steps:
To disable sending SNMP notifications on the physical interface, perform the following steps:
In configuration mode, go to the
[edit interfaces interface-name]
hierarchy level:[edit] user@host# edit interfaces interface-name
Configure the
no-traps
option to disable sending of Simple Network Management Protocol (SNMP) notifications when the state of the connection changes.[edit interfaces interface-name] user@host# set no-traps
See Also
Configuring Ethernet Loopback Capability
To place an interface in loopback mode, include the loopback
statement:
loopback;
To return to the default—that is, to disable loopback
mode—delete the loopback
statement from the configuration:
[edit] user@switch# delete interfaces interface-name ether-options loopback
To explicitly disable loopback mode, include the no-loopback
statement:
no-loopback;
You can include the loopback and no-loopback
statements at the following hierarchy levels:
[edit interfaces interface-name aggregated-ether-options]
[edit interfaces interface-name ether-options]
See Also
Configuring Short Reach Mode on QFX5100-48T
You can enable short-reach mode for individual as well as a range of copper-based 10-Gigabit Ethernet interfaces using short cable lengths (less than 10m) on the QFX5100-48T switch. Short-reach mode reduces power consumption up to 5W on these interfaces.
See Also
Configuring Flow Control
By default, the router or switch imposes flow control to regulate the amount of traffic sent out on a Fast Ethernet, Tri-Rate Ethernet copper, Gigabit Ethernet, and 10-Gigabit Ethernet interface. Flow control is not supported on the 4-port Fast Ethernet PIC. This is useful if the remote side of the connection is a Fast Ethernet or Gigabit Ethernet switch.
You can disable flow control if you want the router or switch
to permit unrestricted traffic. To disable flow control, include the no-flow-control
statement:
no-flow-control;
To explicitly reinstate flow control, include the flow-control
statement:
flow-control;
You can include these statements at the following hierarchy levels:
[edit interfaces interface-name aggregated-ether-options]
[edit interfaces interface-name ether-options]
[edit interfaces interface-name fastether-options]
[edit interfaces interface-name gigether-options]
On the Type 5 FPC, to prioritize control packets in case of ingress oversubscription, you must ensure that the neighboring peers support MAC flow control. If the peers do not support MAC flow control, then you must disable flow control.
See Also
Setting the Mode on an SFP+ or SFP+ MACSec Uplink Module
SFP+ uplink modules are supported on EX3200 and EX4200 switches, and SFP+ Media Access Control Security (MACSec) uplink modules are supported on EX4200 switches. You can use these uplink modules either for two SFP+ transceivers or four SFP transceivers. You configure the operating mode on the module to match the type of transceiver you want to use—that is, for SFP+ transceivers, you configure the 10-gigabit operating mode, and for SFP transceivers, you configure the 1-gigabit operating mode.
By default, the SFP+ uplink module operates in the 10-gigabit mode and supports only SFP+ transceivers. If you have not changed the module from the default setting and you want to use SFP+ transceivers, you do not need to configure the operating mode.
To set the operating mode of an SFP+ or SFP+ MACSec uplink module:
You can see whether the operating mode has been changed to the
new mode you configured by issuing the show chassis pic fpc-slot slot-number pic-slot 1
command.
See Also
Setting the Operating Mode on a 2-Port 40-Gigabit Ethernet QSFP+/100-Gigabit Ethernet QSFP28 Uplink Module
You can configure the 2-port 4-Gigabit Ethernet QSFP+/100-Gigabit Ethernet QSFP28 uplink module on EX4300-48MP switches to operate either two 40-Gigabit Ethernet ports or two 100-Gigabit Ethernet port. By default, the uplink module operates only the two 40-Gbps ports.
The uplink module on EX4300-48MP switches supports Media Access Control Security (MACsec). See Understanding Media Access Control Security (MACsec) for more information.
The uplink module does not support configuring virtual chassis ports.
To set the operating mode on this uplink module:
If you configure both the ports on the uplink module to operate at 100-Gbps speed, the four built-in QSFP+ ports on the switch are disabled.
Starting with Junos
OS Release 19.1R1, in the 2-port 40-Gigabit Ethernet QSFP+/1-port
100-Gigabit Ethernet QSFP28 uplink module of EX4300-48MP switches,
you can channelize the 100-Gigabit four independent 25-Gigabit Ethernet
ports by using breakout cables. You can configure
only port 0 of the uplink module as 25-Gigabit Ethernet port. Issue
the command set chassis fpc 0 pic 2 port 0 channel-speed 25g
to channelize the 100-Gigabit Ethernet uplink port to four 25-Gigabit
Ethernet uplink ports.
Starting with Junos OS Release 19.3R1, you can configure the 2-port 40-Gigabit Ethernet QSFP+/100-Gigabit Ethernet QSFP28 uplink module on EX4300-48MP switches to operate either two 40-Gigabit Ethernet ports or two 100-Gigabit Ethernet ports.
You can also channelize the 40-Gigabit Ethernet interfaces to four independent 10-Gigabit Ethernet interfaces using breakout cables. To channelize the 100-Gigabit Ethernet interfaces to operate as four independent 25-Gigabit Ethernet, specify the port number and channel speed
To configure the 100-Gigabit Ethernet uplink port to operate as a 25-Gigabit Ethernet interface, specify the port number and channel speed by using the following command:
[edit chassis fpc 0 pic 2] user@switch# set port port-number channel-speed speed
For example, to configure port 0 to operate as a 25-Gigabit Ethernet port:
[edit chassis fpc 0 pic 2] user@switch# set port 0 channel-speed 25g
Review your configuration and issue the
commit
command.[edit] user@switch# commit commit complete
If you configure both the ports on the uplink module to operate at 100-Gbps speed, the four QSFP+ ports on the switch are disabled.
See Also
Configuring the Media Type on Dual-Purpose Uplink Ports
EX2200-C switches and ACX1000 routers provide two dual-purpose uplink ports. Each dual uplink port is a single interface that offers a choice of two connections: an RJ-45 connection for a copper Ethernet cable and an SFP connection for a fiber-optic Ethernet cable. You can choose to use either connection, but only one connection can be active at a time.
By default, if you plug a transceiver into the SFP connector, the port becomes a fiber-optic Gigabit Ethernet port, even if a copper Ethernet cable is plugged into the RJ-45 connection as well. If a transceiver is not plugged into the SFP connector, the port defaults to a copper 10/100/1000 Ethernet port.
You can constrain the use of the port to one connection type by configuring the media type for the port to be either copper or fiber. When you configure a media type on the port, the port will no longer accept the alternate connection type. For example, if you configure the uplink port as a fiber port and then plug a copper Ethernet cable into the RJ-45 connector, the interface will not come up.
To configure the media type for an uplink port:
user@switch# set interfaces interface-name media-type (Dual-Purpose Uplink Ports) media-type
For example, to set the media type for uplink port ge-0/1/0 to copper:
user@switch# set interfaces ge-0/1/0 media-type copper
When you change the media type setting for a dual-purpose uplink port, it can take up to 6 seconds for the interface to appear in operational commands.
See Also
Disabling a Physical Interface
- Disabling a Physical Interface
- Example: Disabling a Physical Interface
- Effect of Disabling Interfaces on T series PICs
Disabling a Physical Interface
You can disable a physical interface, marking it as being down, without removing the interface configuration statements from the configuration.
Dynamic subscribers and logical interfaces use physical interfaces for connection to the network. The Junos OS allows you to set the interface to disable and commit the change while dynamic subscribers and logical interfaces are still active. This action results in the loss of all subscriber connections on the interface. Use care when disabling interfaces.
To disable a physical interface:
On the router, when you use the disable
statement
at the edit interfaces
hierarchy level, depending on the
PIC type, the interface might or might not turn off the laser. Older
PIC transceivers do not support turning off the laser, but newer Gigabit
Ethernet PICs with SFP and XFP transceivers do support it and the
laser will be turned off when the interface is disabled.
Do not stare into the laser beam or view it directly with optical instruments even if the interface has been disabled.
Example: Disabling a Physical Interface
Sample interface configuration:
[edit interfaces] user@host# show ge-0/3/2 { unit 0 { description CE2-to-PE1; family inet { address 20.1.1.6/24; } } }
Disabling the interface:
[edit interfaces ge-0/3/2] user@host# set disable
Verifying the interface configuration:
[edit interfaces ge-0/3/2] user@host# show disable; # Interface is marked as disabled. unit 0 { description CE2-to-PE1; family inet { address 20.1.1.6/24; } }
Effect of Disabling Interfaces on T series PICs
The following table describes the effect of using the set
interfaces disable interface_name
statement
on T series PICs.
PIC Model Number |
PIC Description |
Type of PIC |
Behaviour |
---|---|---|---|
PF-12XGE-SFPP |
10-Gigabit Ethernet LAN/WAN PIC with SFP+ (T4000 Router) |
5 |
Tx laser disabled |
PF-24XGE-SFPP |
10-Gigabit Ethernet LAN/WAN PIC with Oversubscription and SFP+ (T4000 Router) |
5 |
Tx laser disabled |
PF-1CGE-CFP |
100-Gigabit Ethernet PIC with CFP (T4000 Router) |
5 |
Tx laser disabled |
PD-4XGE-XFP |
10-Gigabit Ethernet, 4-port LAN/WAN XFP |
4 |
Tx laser disabled |
PD-5-10XGE-SFPP |
10-Gigabit LAN/WAN with SFP+ |
4 |
Tx laser disabled |
PD-1XLE-CFP |
40-Gigabit with CFP |
4 |
Tx laser disabled |
PD-1CE-CFP-FPC4 |
100-Gigabit with CFP |
4 |
Tx laser disabled |
PD-TUNNEL |
40-Gigabit Tunnel Services |
4 |
NA |
PD-4OC192-SON-XFP |
OC192/STM64, 4-port XFP |
4 |
Tx laser not disabled |
PD-1OC768-SON-SR |
OC768c/STM256, 1-port |
4 |
Tx laser not disabled |