Ntron 7506GX2 Series Installation and operating instructions

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7506GX2
Managed Industrial
Gigabit Ethernet Switch
User Manual &
Installation
Guide

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7506GX2 Managed Industrial Gigabit Ethernet Switch Installation Guide.................................................................4
7506GX2 Industrial Ethernet Switch Accessories.......................................................................................................6
SAFETY WARNINGS................................................................................................................................................8
Installation....................................................................................................................................................................9
Connecting the Unit ................................................................................................................................................... 14
Overview of Advanced Features................................................................................................................................18
Mode of Operation..................................................................................................................................................................18
Port Mirroring .........................................................................................................................................................................18
Port Trunking ..........................................................................................................................................................................18
Quality of Service (QoS).........................................................................................................................................................18
Virtual LAN ............................................................................................................................................................................19
Rapid Spanning Tree Protocol ................................................................................................................................................20
SNMP Traps............................................................................................................................................................................20
IGMP Snooping ......................................................................................................................................................................20
N-Ring.....................................................................................................................................................................................21
N-Link.....................................................................................................................................................................................21
CIP ..........................................................................................................................................................................................21
DHCP......................................................................................................................................................................................21
DHCP Client ...........................................................................................................................................................................22
DHCP Relay Agent.................................................................................................................................................................22
DHCP Server...........................................................................................................................................................................22
LLDP.......................................................................................................................................................................................22
Port Security—MAC Address Based......................................................................................................................................22
Web Software Configuration .....................................................................................................................................24
Web Management ...................................................................................................................................................................24
Web Management - Home ......................................................................................................................................................25
Administration –System.........................................................................................................................................................27
Administration –SNMP..........................................................................................................................................................32
Administration –Fault ............................................................................................................................................................34
DHCP –Server –Setup Profiles .............................................................................................................................................35
DHCP –Server –Setup IP Maps ............................................................................................................................................37
DHCP –Server –View Bindings............................................................................................................................................42
DHCP –Relay & Local IP - Setup..........................................................................................................................................43
LLDP - Configuration.............................................................................................................................................................46
LLDP - Ports...........................................................................................................................................................................47
LLDP - Status..........................................................................................................................................................................48
LLDP - Statistics.....................................................................................................................................................................49
Ports –Configuration ..............................................................................................................................................................50
Ports –MAC Security –Learning...........................................................................................................................................52
Ports –MAC Security –Authorization List............................................................................................................................53
Ports –MAC Security –Intruder Log.....................................................................................................................................54
Ports –Mirroring.....................................................................................................................................................................55
Ports –Trunking......................................................................................................................................................................57
Ports –QoS .............................................................................................................................................................................58
Statistics –Port Statistics ........................................................................................................................................................60
Statistics –Port Utilization......................................................................................................................................................61
VLAN –Configuration ...........................................................................................................................................................62
Bridging –Aging Time ...........................................................................................................................................................64
Bridging –Unicast Addresses.................................................................................................................................................65
Bridging –Multicast Addresses ..............................................................................................................................................67
Bridging –Show MAC by Port...............................................................................................................................................69
RSTP –Configuration.............................................................................................................................................................71
IGMP –Configuration ............................................................................................................................................................75
IGMP –Show Group and Show Router..................................................................................................................................78
IGMP –RFilter .......................................................................................................................................................................79
N-View –Configuration..........................................................................................................................................................81
N-View –Ports........................................................................................................................................................................82
N-Ring –Configuration ..........................................................................................................................................................84
N-Ring –Advanced Configuration .........................................................................................................................................87

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N-Ring –Status.......................................................................................................................................................................89
N-Link –Configuration...........................................................................................................................................................93
N-Link –Status .......................................................................................................................................................................97
CIP - Configuration...............................................................................................................................................................102
CIP –Status...........................................................................................................................................................................103
Firmware/Config –TFTP......................................................................................................................................................104
Support –Web Site and E-mail.............................................................................................................................................106
BPCL –Broadcast Packet Count Limit Configuration .........................................................................................................107
User Management –Adding Users .......................................................................................................................................108
User Management –Removing Users...................................................................................................................................109
Logical View.........................................................................................................................................................................110
Configuration –Save or Reset...............................................................................................................................................112
Help –Overview ...................................................................................................................................................................114
Help –Administration...........................................................................................................................................................115
Help –DHCP ........................................................................................................................................................................116
Help –LLDP.........................................................................................................................................................................117
Help –Ports...........................................................................................................................................................................118
Help –Statistics.....................................................................................................................................................................119
Help –VLAN........................................................................................................................................................................120
Help –Bridging.....................................................................................................................................................................121
Help –RSTP .........................................................................................................................................................................122
Help –IGMP.........................................................................................................................................................................123
Help –N-View......................................................................................................................................................................124
Help –N-Ring.......................................................................................................................................................................125
Help –N-Link.......................................................................................................................................................................126
Help –CIP.............................................................................................................................................................................127
Help –Firmware/Config .......................................................................................................................................................128
Help –BPCL.........................................................................................................................................................................129
Help –User Management......................................................................................................................................................130
Help –Other..........................................................................................................................................................................131
CLI Commands........................................................................................................................................................ 132
―?‖ (Help) ..............................................................................................................................................................................132
Logout...................................................................................................................................................................................132
Show, Add, or Delete ARL Entries.......................................................................................................................................133
Configuration Device Operations..........................................................................................................................................134
Show or Set CIP Configuration.............................................................................................................................................135
Save or Reset the Configuration Settings..............................................................................................................................136
Show or Set IGMP Configuration.........................................................................................................................................136
Show or Set Mirror Configuration ........................................................................................................................................137
Show or Set N-Ring Configuration.......................................................................................................................................138
Show or Set N-View Configuration......................................................................................................................................138
Ping a Host............................................................................................................................................................................139
Show or Set Port Configuration ............................................................................................................................................140
Reset the Switch....................................................................................................................................................................141
Show or Set SNMP Configuration........................................................................................................................................141
Show or Clear the Last System Error....................................................................................................................................142
Show System Information.....................................................................................................................................................142
Set or Show the System IP Configuration.............................................................................................................................143
Show or Set System Configuration .......................................................................................................................................144
VLAN Addition and Deletion Example...................................................................................................................145
VLAN Configuration Examples .............................................................................................................................. 150
Example 1 –Basic understanding of port-based VLANs......................................................................................................150
Example 2 –Basic understanding of tagged VLANs (Admit –Tagged Only) .....................................................................151
Example 3 –Basic understanding of tagged VLANs (Admit –All).....................................................................................152
Example 4 –Basic understanding of Hybrid VLANs ...........................................................................................................153
Example 5 –Basic understanding of Overlapping VLANs...................................................................................................154
Example 6 –Basic understanding of VLANs with Multicast Filtering.................................................................................155
KEY SPECIFICATION...........................................................................................................................................156
N-TRON Limited Warranty.....................................................................................................................................158

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7506GX2 Managed Industrial Gigabit Ethernet Switch Installation Guide
The N-TRON 7506GX2 Series Industrial Gigabit Ethernet Switch offers outstanding performance and ease
of use. It is ideally suited for connecting Ethernet enabled industrial and or security equipment and is a fully
managed switch.

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PRODUCT FEATURES
• Full IEEE 802.3 Compliance
• Four 10/100/1000BaseT(X) RJ-45 Ports
• Two SFP (Mini-GBIC) Gigabit Transceivers
(Optional)
o1000BaseSX/LX Fiber with LC style connectors
or
o1000BaseT Copper with RJ-45 connectors
• Extended Environmental Specifications
-40° to 80°C Surrounding Air Temperature
• ESD and Surge Protection Diodes on all Ports
• Auto Sensing 10/100/1000BaseT(X), Duplex, and
MDIX
• Store-and-forward Technology
• Rugged DIN-Rail Enclosure
• Onboard Temperature Sensor
• Redundant Power Inputs (10-49VDC)
• Configurable Bi-Color Fault Status LED
PRODUCT CONFIGURATIONS
• 7506GX2
–Four 10/100/1000 Base-T RJ45 Copper Ports,
and two optional SFP transceivers
Supported SFP (Mini-GBIC) Fiber Transceivers:
NTSFP-SX (LC Style Connector, up to 550m)
NTSFP-LX-10 (LC Style Connector, up to 10km)
NTSFP-LX-40 (LC Style Connector, up to 40km)
NTSFP-LX-80 (LC Style Connector, up to 80km)
MANAGEMENT FEATURES
• SNMP v1, v2, v3 and Web Browser Management
• Configuration backup via Optional Configuration Device (NTCD)
• Jumbo Frame Support
• EtherNet/IP™ CIP Messaging
• Detailed Ring Map and Fault Location Charting
• N-Ring™ Technology with ~30ms Healing
• Web Browser Management with detailed ring map and
fault location charting.
• N-View™ OPC Monitoring
• N-Link™ Redundant N-Ring Coupling
• IGMP Auto Configuration and Plug and Play Support
• 802.1Q tag VLAN and Port VLAN
• 802.1p QoS, Port QoS, and DSCP
• LLDP (Link Layer Discovery Protocol)
• Trunk with other N-Tron trunking capable switches over two ports
• Port Mirroring
• 802.1d, 802.1w, 802.1D RSTP (Rapid Spanning Tree Protocol)
• DHCP Client, Server, Option 82 relay, Option 61
• Local Port IP Addressing
• Port Security—MAC Address Based

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7506GX2 Industrial Ethernet Switch Accessories
NTCD-SD
Configuration Device
Ideal for saving, or restoring switch configuration
parameters quickly without the need for a computer or
software. One configuration device per switch is
recommended.

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Copyright, © N-Tron Corp., 2008-2009
820 S. University Blvd., Suite 4E
Mobile, AL 36609 USA
All rights reserved. Reproduction, adaptation, or translation without prior written permission from N-Tron
Corp. is prohibited, except as allowed under copyright laws.
Ethernet is a registered trademark of Xerox Corporation. All other product names, company names, logos
or other designations mentioned herein are trademarks of their respective owners.
The information contained in this document is subject to change without notice. N-Tron Corp. makes no
warranty of any kind with regard to this material, including, but not limited to, the implied warranties of
merchantability or fitness for a particular purpose. In no event shall N-Tron Corp. be liable for any
incidental, special, indirect or consequential damages whatsoever included but not limited to lost profits
arising out of errors or omissions in this manual or the information contained herein.
Warning
Do not perform any services on the unit unless qualified to do so. Do not substitute unauthorized parts or
make unauthorized modifications to the unit.
Do not operate the unit with the top cover removed, as this could create a shock or fire hazard.
Do not block the air vents on the sides or the top of the unit.
Do not operate the equipment in the presence of flammable gasses or fumes. Operating electrical equipment
in such an environment constitutes a definite safety hazard.
Do not operate the equipment in a manner not specified by this manual.

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SAFETY WARNINGS
GENERAL SAFETY WARNINGS
WARNING: If the equipment is used in the manner not specified by N-Tron Corp., the protection
provided by the equipment may be impaired.
Maximum surrounding air temperature rating: 80°C
LASER SAFETY (7506GX2 Model with optional NTSFP-LX -10, -40 and -80)
CAUTION: CLASS 1 LASER PRODUCT. Do not stare into the laser!
Contact Information
N-Tron Corp.
820 South University Blvd. Suite 4E
Mobile, AL 36609
TEL: [phone]
FAX: [phone]
WEBSITE: www.n-tron.com
E-MAIL: [email protected]
ENVIRONMENTAL SAFETY
WARNING: Disconnect the power and allow to cool 5 minutes before touching.
ELECTRICAL SAFETY
Must be used with Listed UL Industrial Power Supply.
WARNING: Disconnect the power cable before removing the top cover.
WARNING: Do not operate the unit with the any cover removed.
WARNING: Properly ground the unit before connecting anything else to the unit. Units not properly
grounded may result in a safety risk and could be hazardous and may void the warranty. See the grounding
technique section of this user manual for proper ways to ground the unit.
WARNING: Do not work on equipment or cables during periods of lightning activity.

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WARNING: Do not perform any services on the unit unless qualified to do so.
WARNING: Do not block the air vents.
WARNING: Observe proper DC Voltage polarity when installing power input cables. Reversing voltage
polarity can cause permanent damage to the unit and void the warranty.
Hazardous Location Installation Requirements
1. WARNING: Explosion Hazard –Substitution of components may impair suitability for Class I,
Div. 2.
2. WARNING: Explosion Hazard - do not disconnect while circuit is live, unless area is known to be
non-hazardous.
3. WARNING: Explosion Hazard –do not replace the device unless power has been switched off or
the area is known to be non-hazardous.
4. Use 90°C or higher rated Copper wire, (0.22Nm) 2lb/in tightening torque for field installed
conductors.
5. The USB Port is for temporary connection only. Do not use, connect, or disconnect unless area is
known to be non-hazardous. Connection or disconnection in an explosive atmosphere could result in
an explosion.
6. The SD Card connector is for temporary connection only. Do not use, connect, or disconnect unless
area is known to be non-hazardous. Connection or disconnection in an explosive atmosphere could
result in an explosion.
Please make sure the 7506GX2 Ethernet Switch package contains the following items:
1. 7506GX2 Switch
2. Product CD
Contact your carrier if any items are damaged.
Installation
Read the following warning before beginning the installation:
WARNING
Never install or work on electrical equipment or cabling during periods of lightning activity. Never connect
or disconnect power when hazardous gasses are present.
Disconnect the power cable before removing any enclosure panel.
UNPACKING

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Remove all the equipment from the packaging, and store the packaging in a safe place. File any damage
claims with the carrier.
CLEANING
Clean only with a damp cloth.

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DIN RAIL MOUNTING
Install the unit on a standard 35mm Din-Rail. Recess the 7506GX2 unit to allow at least 3‖ of horizontal
clearance for copper cable bend radius. Recess the 7506GX2 unit to allow at least 5‖ of horizontal
clearance for fiber cable bend radius. There should be at least 3‖ of clearance on both the top and bottom of
the unit to allow proper ventilation.
To install the unit to 35mm industrial DIN rail,
place the top edge of the included mounting
bracket on the back of the unit against the DIN rail
at a 15° angle as shown. Rotate the bottom of the
unit to the back (away from you) until it snaps into
place.
To remove the unit from the 35mm industrial
DIN rail, pull forward on the unit until it disengages
from the bottom of the DIN rail. Rotate the bottom
of the unit towards you and up at an approximate
15° upward angle to completely remove the unit.
URMK 1000-PM
Most N-Tron™ products are designed to be mounted on industry standard 35mm DIN rail. However, DIN
rail mounting may not be suitable for all applications. Our Universal Rack Mount Kit (P/N: URMK) may be
used to mount the 7506GX2 enclosure to standard 19" racks, and our Panel Mount Assembly (P/N: 1000-
PM) may be used to mount the 7506GX2 enclosure to a panel or any other flat surface.

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FRONT PANEL
From Top to Left:
LED lights when Power is supplied to the unit
USB Command Line Interface (CLI)
RJ45 Ports Auto Sensing 10/100/1000 Base-T Connections
NTCD N-Tron Configuration Device
Gigabit Ports 1000 Base SFP Fiber Transceivers (Optional)
NOTE: The RJ45 data ports have two LEDs located on each connector. The bottom LED indicates the
SPEED, and the top LED indicates LINK/ACTIVITY.
LEDs: The table below describes the operating modes:
LED
Color
Description
GREEN
Power is ON
RED
Power is ON and a fault condition exists
OFF
Power is OFF
SPEED
1000
GREEN
Link is 1000Mbs
OFF
Link is 10/100Mbs
LNK/ACT
GREEN
Link established, no Activity on cable.
BLINKING
Link established, Activity on cable.
OFF
No Link activity between ports

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APPLYING POWER (Side View)
Unscrew & Remove the DC Voltage Input Plug from the top header.
Install the DC Power Cables into the Plug (observing polarity on unit).
Plug the Voltage Input Plug back into the top header.
Tightening torque for the terminal block power plug is 0.5 Nm/0.368 Pound Foot.
All LEDs will flash ON Momentarily.
Verify the Power LED stays ON (GREEN).
Notes:
Only 1 power supply must be connected to power for minimal operation. For redundant power
operation, V1and V2inputs must be connected to separate DC Voltage sources. This device will
draw current from both sources simultaneously. Use 16-28 gauge wire when connecting to the
power supply.
Recommended 24V DC Power Supplies, similar to: N-Tron‘s P/N NTPS-24-1.3:
Input AC 115/230V
Output DC 24-28V
Output Current 1.3A @ 24V
1.0A @ 28V
Power 30W
35 mm DIN-Rail Mountable
Dimensions: 45X75X91 mm

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Connecting the Unit
For 10/100/1000 Base-T ports, plug a Category 5E twisted pair cable into the RJ45 connector. Connect the
other end to the far end station. Verify that the LNK/ACT LEDs are ON once the connection has been
completed. To connect any port to another device (end node, Switch or Repeater), use a standard Category
5E straight through or crossover cable
with a minimum length of one meter and a
maximum length of 100 meters.
N-Tron recommends the use of pre-
manufactured Cat5E cables to ensure the
best performance. If this is not an option
and users must terminate their own ends
on the Cat5E cables; one of the two color
coded standards shown to the right should
be utilized. If a user does not follow one
of these two color code standards then the
performance and maximum cable distance
will be reduced significantly, and may
prevent the switch from establishing a
link.
For LC style fiber optic connections, remove the dust cap from the SFP modules and connect the fiber optic
cables. The TX port should be connected to the RX port of the far end station. The RX port should be
connected to the TX port of the far end station.
Warning: Creating a port to port connection on the same switch (i.e. loop) is an illegal operation and
will create a broadcast storm which will crash the network!

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N-TRON SWITCH GROUNDING TECHNIQUES
The grounding philosophy of any control system is an integral part of the design. N-Tron switches are
designed to be grounded, but the user has been given the flexibility to float the switch when required. The
best noise immunity and emissions (i.e. CE) are obtained when the N-Tron switch chassis is connected to
earth ground via a drain wire. Some N-Tron switches have metal din-rail brackets that can ground the
switch if the din-rail is grounded. In some cases, N-Tron switches with metal brackets can be supplied with
optional plastic brackets if isolation is required.
Users may run a drain wire & lug from the screw provided on the back face of
the enclosure. In the event the provided grounding screw has been lost, care
should be taken to limit the penetration of the outer skin by less than 1/4".
Failure to do so may cause irreversible damage to the internal components of
the switch.
Note: Ensure the power supply is grounded properly before applying power to
the grounded switch. This may be verified by using a voltmeter to determine
that there is no voltage difference between the power supply’s negative output
terminal and the chassis grounding point of the switch.
As an alternative grounding method, both V- legs of the power
input connector are connected to chassis internally on the PCB.
Connecting a drain wire to earth ground from one of the V-
terminal plugs as shown here will ground the switch and the
chassis. The power leads from the power source should be limited
to 3 meters or less in length.
Note: Before applying power to the grounded switch, you must use a volt meter to verify there is no voltage
difference between the power supply’s negative output terminal and the switch chassis grounding point.
If the use of shielded cables is required, it is generally recommended to only connect the shield at one end to
prevent ground loops and interfere with low level signals (i.e. thermocouples, RTD, etc.). Cat5e cables
manufactured to EIA-568A or 568B specifications are required for use with N-Tron Switches.
In the event all Cat5e patch cable distances are small (i.e. All Ethernet devices are located in the same local
cabinet and/or referenced to the same earth ground), it is permissible to use fully shielded cables terminated
to chassis ground at both ends in systems void of low level analog signals.
DRAIN WIRE WITH LUG CONNECTING SWITCH
CHASSIS TO KNOWN GOOD GROUNDING POINT.
DRAIN WIRE WITH
LUG CONNECTING
SWITCH CHASSIS
TO KNOWN GOOD
GROUNDING
POINT.
METALLIC
DIN-RAIL CLIP

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RJ45 CONNECTOR CRIMP SPECIFICATIONS
Please reference the illustration below for your Cat5 cable specifications:

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USB INTERFACE
The 7506GX2 Series switches provide a USB interface accessed via the USB connector labeled as ―USB‖
on the unit. This is used to access the Command Line Interpreter (CLI).
USB Cable
Connect the USB port of your PC and the 7506GX2 Series Switch using a standard USB cable. You will
require a cable with a Type A connector for the PC end, and a Type B connector for the 7506GX2 Series
end.
Standard USB cables are readily available from a variety of computer stores.
HyperTerminal
The following configuration should be used in HyperTerminal:
Port Settings: 115200
Data Bits: 8
Parity: NONE
Stop bits: 1
Flow Control: NONE

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Overview of Advanced Features
Mode of Operation
Each port on the switch can be configured into different modes of operation as shown below:
Copper Ports: 1000Base Fiber Ports:
- Half Duplex - Full Duplex
- Full Duplex
- Auto Negotiation
Half Duplex
In half duplex mode, the CSMA/CD media access method is the means by which two or more stations share
a common transmission medium. To transmit, a station waits (defers) for a quiet period on the medium (that
is, no other station is transmitting) and then sends the intended message in bit-serial form. If, after initiating
a transmission, the message collides with that of another station, then each transmitting station intentionally
transmits for an additional predefined period to ensure propagation of the collision throughout the system.
The station remains silent for a random amount of time (back-off) before attempting to transmit again.
Full Duplex
Full duplex operation allows simultaneous communication between a pair of stations using point-to-point
media (dedicated channel). Full duplex operation does not require that transmitters defer, nor do they
monitor or react to receive activity, as there is no contention for a shared medium in this mode.
Auto Negotiation
In Auto Negotiation mode, the port / hardware detects the mode of operation of the station that is connected
to this port and sets its mode to match the mode of the station.
Port Mirroring
A Mirroring Port is a dedicated port that is configured to receive the copies of Ethernet frames that are being
transmitted out and also being received in from any other port that is being monitored.
Port Trunking
Port Trunking is the ability to group two network ports to increase the bandwidth between two machines
(switch or any work station). This feature allows grouping of high-speed connectivity and provides
redundant connection between switches, so that a trunk can act as a single link between the switches.
Quality of Service (QoS)
Quality of service (QoS) refers to resource reservation control mechanisms. Quality of service is the ability
to provide different priority to different applications, users, or data flows. Quality of service guarantees are
important if the network capacity is insufficient, especially for real-time streaming multimedia applications
such as voice over IP, online games and IP-TV, since these often require fixed bit rate and are delay
sensitive, and in networks where the capacity is a limited resource, for example in cellular data
communication. In the absence of network congestion, QoS mechanisms are not required.

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Each of these three QOS methods below is included or not based on the settings on the relevant browser
page:
1) Force High Priority (Port Based),
2) IEEE802.1p (Tagged QOS), or
3) DSCP (differentiated services code points) (RFC 2474).
When Force High Priority is enabled, the port based priority is included in the decision for all ports and all
frames received on a port will use the default QOS priority for that port in the decision. For example, if it is
desired to have ingress frames on a port egress to the highest priority transmit queue regardless of other
factors, then enable Force High Priority and set the port's Default Port Priority to 7.
Virtual LAN
The switch provides support for setting up tagged Virtual LANs (Local Area Networks). A port may belong
to any number of Virtual LANs. The VLAN membership of a device is determined by the VLAN(s) that
have been defined for the port to which the device is connected. If a device should move from one port to
another, it loses its current VLAN membership and inherits that of the new port it is connected to.
VLANs facilitate easy administration of logical groups of devices that can communicate as if they
were on the same LAN. Traffic between VLANs is restricted, unless the ports are explicitly configured
as overlapping VLANs. Switches forward unicast, multicast, and broadcast traffic only on LAN segments
that serve the VLAN to which the traffic belongs.
A Default Virtual LAN (VID=1) exists to which a port, which is not a member of any other Virtual LAN,
will belong. This allows the switch to operate as a ‗normal‘ switch when it is used in a network. A port is
automatically removed from the Default VLAN when it is reconfigured to belong to another Virtual LAN,
because that is the most common operation. But, if desired, the port can be included in VLAN 1 by
configuring VLAN 1 last.
If switch ports are configured to transmit and receive untagged frames, end devices are able to communicate
throughout the LAN. Using Tagged VLANs, the switch has the ability to take non-tagged packets in some
ports, add a VLAN tag to the packet and send it out tagged ports on the switch. The VLANs can also be
configured to accept tagged packets in tagged ports, strip the tags off the packets, and send the packets back
out other untagged ports. This allows a network administrator to set up the switch to support devices on the
network that do not support VLAN Tagged packets. The administrator can also set up the ports to discard
any packets that are tagged or to discard any packets that are untagged based on a hybrid VLAN of both
tagged and untagged ports, and using the VLAN Ingress Filter on the switch.
For each switch port there is one and only one PVID (port VLAN ID) setting. If an incoming frame is
untagged and untagged frames are being accepted, then that frame will inherit the tag of the PVID value for
that port. Subsequent switch routing and treatment will be in accordance with that VLAN switch map. By
configuring PVIDs properly and configuring for all frames to exit untagged, the switch can achieve a ‗port
VLAN‘ configuration in which all frames in and out can be untagged, thus not requiring external devices to
be VLAN cognizant.
To understand how a VLAN configuration will perform, first look at the port on which the frame enters the
switch, then the VLAN ID (if the frame is tagged) or the PVID (if the frame is untagged). The VLAN
defined by the VID or PVID defines a VLAN group with a membership of ports. This membership
determines whether a port is included or excluded as to frame egress from the switch.
The 7506GX2 Series switch also has the ability to allow overlapping VLANs. Overlapping VLANs give

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the user the ability to have one or more ports share two or more VLAN groups. For more information and
examples on how this could be implemented, please see the ‗VLAN Configuration Examples‘ in this
document, and/or our website‘s technical documents. Note that RSTP on overlapping VLANs is not
supported and the system will automatically disable RSTP on all but the lowest VID VLANs that have
overlapping ports.
Rapid Spanning Tree Protocol
The Rapid Spanning Tree Protocol as specified in IEEE 802.1D-2004 is supported. One Spanning Tree per
non-overlapping VLAN is supported. The Rapid Spanning Tree Protocol (RSTP) supersedes the Spanning
Tree Protocol (STP) which was described in IEEE 802.1D-1998. The RSTP is used to configure a simply
connected active network topology from the arbitrarily connected bridges of a bridged network. Bridges
effectively connect just the LANs to which their forwarding ports are attached. Ports that are in a blocking
state do not forward frames. The bridges in the network exchange sufficient information to automatically
derive a spanning tree.
RSTP allows for much quicker learning of network topology changes than the older STP. RSTP supports
new and improved features such as rapid transition to forwarding state. RSTP also sends out new BPDUs
every hello time instead of just relaying them. RSTP interoperates with older STP switches by falling back
to the older STP when the older BPDUs are detected on bridge ports. The user can also manually configure
bridge ports to use the older STP when desired.
SNMP Traps
The 7506GX2 switch supports up to 5 SNMP Trap Stations to which SNMP Traps will be sent. The switch
supports five standard traps; Link Up, Link Down, Cold Start, Warm Start and Authentication Errors.
SNMP Traps will be sent to all the trap stations configured on the switch when the corresponding trap is
enabled.
IGMP Snooping
IGMP Snooping is enabled by default, and the switch is Plug and Play for IGMP. IGMP snooping provides
intelligent network support for multicast applications. In particular, unneeded traffic is reduced. IGMP
Snooping is configured via the web console and if enabled, operates dynamically upon each power up.
Also, there can be manual only or manual and dynamic operation. Note that ―static multicast group
address‖ can be used whether IGMP Snooping is enabled or not.
IGMP Snooping will function dynamically without user intervention. If some of the devices in the LAN do
not understand IGMP, then manual settings are provided to accommodate them. The Internet Group
Management Protocol (IGMP) is a protocol that provides a way for a computer to report its multicast group
membership to adjacent ‗routers‘. In this case N-Tron 7506GX2 switches provide router-like functionality.
Multicasting allows one computer to send content to multiple other computers that have identified
themselves as interested in receiving the originating computer's content. Multicasting can be used to
transmit only to an audience that has joined (and not left) a multicast group membership. IGMP version 2 is
formally described in the Internet Engineering Task Force (IETF) Request for Comments (RFC) 2236.
IGMP version 1 is formally described in the Internet Engineering Task Force (IETF) Request for Comments
(RFC) 1112. The 7506GX2 supports v1 and v2.