Juniper EX2200 Hardware Guide

NOTE: The actual frames transmitted also contain cyclic redundancy check
(CRC) bits, which are not part of the media MTU. For example, the media
MTU for a Gigabit Ethernet Version 2 interface is specified as 1514 bytes, but
the largest possible frame size is actually 1518 bytes; you need to consider
the extra bits in calculations of MTUs for interoperability.
The physical MTU for Ethernet interfaces does not include the 4-byte frame
check sequence (FCS) field of the Ethernet frame.
A SONET/SDH interface operating in concatenated mode has a “c” added
to the rate descriptor. For example, a concatenated OC48 interface is referred
to as OC48c.
If you do not configure an MPLS MTU, the Junos OS derives the MPLS MTU
from the physical interface MTU. From this value, the software subtracts the
encapsulation-specific overhead and space for the maximum number of
labels that might be pushed in the Packet Forwarding Engine. Currently, the
software provides for three labels of four bytes each, for a total of 12 bytes.
In other words, the formula used to determine the MPLS MTU is the following:
MPLS MTU = physical interface MTU – encapsulation overhead – 12
If you configure an MTU value by including the mtu statement at the [edit
interfaces interface-name unit logical-unit-number family mpls] hierarchy level,
the configured value is used.
How to Configure the Media MTU
To modify the default media MTU size for a physical interface, include the mtu statement
at the [edit interfaces interface-name] hierarchy level:
[edit interfaces interface-name]
mtu bytes;
If you change the size of the media MTU, you must ensure that the size is equal to or
greater than the sum of the protocol MTU and the encapsulation overhead.
NOTE: Changing the media MTU or protocol MTU causes an interface to be
deleted and added again.
You configure the protocol MTU by including the mtu statement at the following hierarchy
levels:
•
[edit interfaces interface-name unit logical-unit-number family family]
•
[edit logical-systems logical-system-name interfaces interface-name unit
logical-unit-number family family]
55Copyright © 2015, Juniper Networks, Inc.
Chapter 2: Configuration Tasks

Juniper EX2200 Specifications

General

Throughput	77 Mpps
MAC address table	8000 entries
Jumbo frames support	Yes
Number of VLANs	1024
Networking standards	-
Switch type	Managed
SFP module slots quantity	4
Installed SFP modules quantity	0
Basic switching RJ-45 Ethernet ports quantity	48
Stackable	No
Product color	Black
Power consumption (typical)	100 W
Operating altitude	0 - 3048 m
Non-operating altitude	0 - 4877 m
Storage temperature (T-T)	-40 - 70 °C
Operating temperature (T-T)	0 - 45 °C
Storage relative humidity (H-H)	0 - 95 %
Operating relative humidity (H-H)	10 - 85 %

Weight and Dimensions

Depth	254 mm
Width	441 mm
Height	43 mm
Weight	3600 g