EtherSwitch Network and Service Modules on 2600/3600/3700 Series Routers FAQ

Introduction

This document answers frequently asked questions (FAQ) about hardware and software support for the Cisco 2600/3600/3700 series 16-port and 36-port EtherSwitch network and service modules. The document also covers the functionality and basic setup design of these modules. Both port configuration models come in versions that support standard and inline power. The models and part numbers are:

• NM-16ESW 16-Port 10/100 EtherSwitch Network Module (NM)

• NM-16ESW-PWR 16-Port 10/100 EtherSwitch NM with Inline Power Support

• NMD-36-ESW  36-Port 10/100 EtherSwitch High Density Service Module (HDSM)

• NMD-36-ESW-PWR 36-Port 10/100 EtherSwitch HDSM with Inline Power Support

For more information on document conventions, refer to the Conventions Used in Cisco Technical Tips.

Q. Describe the 16-port and 36-port EtherSwitch modules.

A. There are two modules for the 2600/3600/3700 routers: a 16-port 10/100 NM, and a 36-port 10/100 HDSM. These modules allow 2600/3600/3700 router customers to now integrate high-performance Layer 2 (L2) switching into the routing chassis. Both modules have autosensing 10/100 ports and line-rate L2 performance. The modules both offer optional Gigabit Ethernet and Cisco-based inline power for IP phones and Aironet wireless base stations. Other features include port autosensing, QoS and VLAN support from IEEE 802.1p and IEEE 802.1Q standards, and IEEE 802.1D Spanning Tree Protocols (STPs). Cisco-based inline power requires an external or internal power supply. Only the 3700 series offers internal power. The 16-port EtherSwitch NM can accept a single-port Gigabit Ethernet daughtercard. The 36-port EtherSwitch HDSM can accept up to two single-port Gigabit Ethernet daughtercards.

With these modules, the 2600/3600/3700 series routers can provide a single box solution for branch offices that deploy converged IP telephony. The routers can extend data, voice, and video through the delivery of IP routing, Ethernet switching, fixed wireless solutions, and voice gateway capabilities. The modularity of these platforms ensures investment protection and lower cost of ownership.

Q. Provide a support matrix for the Cisco 2600, 3660, 3725, and 3745 with use of the EtherSwitch module.

Chassis	16-port EtherSwitch NM	36-port EtherSwitch HDSM	Gigabit Ethernet (1000BASE-T) Ports	External Power Supply	Internal Power Supply
2600 Series	1	Not supported	1	Required for inline phone support	Not supported
3660 Series	Yes, 2 per router	Yes, 2 per router	1 for 16-port EtherSwitch, 2 for 36-port EtherSwitch	Required for inline phone support	Not supported
3725	Yes, 2 per router	Yes, 1 per router	1 for 16-port EtherSwitch, 2 for 36-port EtherSwitch	Not required	Supports 1 integrated inline power supply
3745	Yes, 2 per router	Yes, 2 per router	1 for 16-port EtherSwitch, 2 for 36-port EtherSwitch	Not required	Supports 2 integrated inline power supplies

Q. Can you configure a port on the EtherSwitch module as a routed port?

A. With the release of Cisco IOS® Software Releases 12.2(15)ZJ and 12.3(4)T, you can assign an IP address directly to ports of the EtherSwitch module. This feature makes those ports Layer 3 (L3) or routed ports. These ports cannot receive a DHCP address, and the ports do not support subinterfaces. L3 traffic on the routed ports still requires that the traffic utilize the platform routing engine. No L3 switching occurs on the blade. You can use all routing protocols in conjunction with this feature. This configuration serves as an example:

interface FastEthernet1/0 
no switchport 
ip address 172.16.1.0 255.255.0.0

Q. Is there a way to determine the installation of EtherSwitch modules without the need to look at the router?

A. Yes, you can issue the show version command or the show diag command. For the 16-port NM, the show version command displays:

16 Fast Ethernet/IEEE 802.3 interface(s)

For the 36-port HDSM, the show version command displays:

36 Fast Ethernet/IEEE 802.3 interface(s)

For the 16-port NM, the show diag command displays:

Fast Ethernet Port adapter, 16 ports

For the 36-port HDSM, the show diag command displays:

Fast Ethernet Port adapter, 36 ports

Q. What devices can you connect to the EtherSwitch modules?

A. You can connect these devices to the EtherSwitch modules:

• A PC or workstation

• An IP telephone

• An Aironet access point or base station

• A port on a Cisco Catalyst series switch

• Cisco CallManager

Also, any other 10/100 transmit (Tx) port that Cisco offers, such as a NM-1FE2W for the Cisco 2600, 3600, and 3700 series, and most hubs should work fine.

Q. Where can you use the optional Gigabit Ethernet daughtercard?

A. You can use the Gigabit Ethernet daughtercard as an uplink port to a file server or as a trunk port to another Cisco Catalyst switch. The 36-port EtherSwitch HDSM supports up to two Gigabit Ethernet daughtercards. You must use the Gigabit Ethernet interface to stack intrachassis between modules. When you insert a second EtherSwitch module into a 3600 or 3700 series router, you must link the modules at Layer 2 (L2) with use of the Gigabit Ethernet interfaces on the two modules. You should account for this when you order. Also, with Cisco IOS Software Releases 12.2(15)ZJ, 12.3(4)T, and later, you can also configure the Gigabit Ethernet interface as a L3 or routed interface.

Q. What are the differences between the 4-port Ethernet NMs (NM-4E) and the EtherSwitch modules?

A. The EtherSwitch modules are Layer 2 (L2) switches, whereas the NM-4E is a Layer 3 (L3) routing device. All 16 or 36 of the ports on the EtherSwitch modules have a high-speed switch fabric within the NM. This switch fabric enables devices that connect to the EtherSwitch module and belong to the same VLAN to benefit from line-rate switching in hardware. Cisco IOS Software Releases 12.2(15)ZJ and 12.3(4)T can directly associate an IP address with Fast Ethernet or Gigabit Ethernet interfaces on the EtherSwitch module. The feature makes the EtherSwitch module functionally equivalent to the NM-4E, except that the EtherSwitch module has Fast Ethernet interfaces.

Q. Does the EtherSwitch support Fast EtherChannel?

A. The EtherSwitch modules support a maximum of eight interfaces per EtherChannel when you have set all interfaces in the EtherChannel at the same speed/duplex.

Q. Do the EtherSwitch modules support Layer 2 (L2) switching and interVLAN routing via the router CPU?

A. Yes, the EtherSwitch modules support L2 switching for traffic between all the ports that belong to the same VLAN. For interVLAN routing, the modules use Layer 3 (L3) VLAN interface, which represents a VLAN at L3. All the L2 traffic in a VLAN to route goes to the L3 VLAN interface. This L3 VLAN interface receives support in conjunction with the EtherSwitch to route traffic at L3. You can apply access control lists (ACLs), routing, and IP addressing on this L3 interface.

Q. What current Cisco Catalyst software is the basis for EtherSwitch modules, and do these NMs use Cisco IOS Software command-line interface (CLI)?

A. Catalyst Cisco IOS Software is the basis for the EtherSwitch modules. Because the current Cisco 2600, 3600, and 3700 series integrate these modules, the modules natively support Cisco IOS Software CLI. There is no separate image top load on the module.

Q. Can you stack between two EtherSwitch modules in two different routers?

A. You can stack between two chassis functions in the same way that you stack between an EtherSwitch module and an external Cisco Catalyst switch. You must connect the modules via an IEEE 802.1Q trunk connection.

Q. What is intrachassis stacking?

A. Intrachassis stacking is the ability to connect multiple EtherSwitch modules via the Gigabit Ethernet connection in the same router. For example, to stack intrachassis is to place two EtherSwitch modules in the same router and connect the modules via the Gigabit Ethernet uplink. Cisco IOS Software Releases 12.2(11)T, 12.3(4)T, and later support this functionality. Two modules in any router is the limit for an intrachassis stack. An intrachassis stack requires a Gigabit Ethernet interface on each module. You must connect the modules externally with the Gigabit Ethernet interfaces and a crossover cable. Intrachassis stacks allow all the Fast Ethernet and Gigabit Ethernet interfaces to participate in the same Layer 2 (L2) domain.

Q. Can you stack two EtherSwitch modules in a chassis without the need to connect the Gigabit Ethernet ports?

A. No, there is no support to stack without a connection of the two Gigabit Ethernet interfaces. Connection of the two Gigabit Ethernet interfaces and use of the stacking-partner command eliminates conflicts in the VLAN databases between the two modules. If you install two modules without this connection, the result is duplications in the VLAN databases. There is no support for such duplications.

Q. How do you connect two EtherSwitch modules in the same chassis?

A. Use the Gigabit Ethernet ports and a crossover Ethernet cable to connect two EtherSwitch blades. This allows both EtherSwitch modules to become a single Layer 2 (L2) domain. You must use the gigabit interface command switchport stacking-link. Refer to the 16- and 36-Port Ethernet Switch Module for Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series configuration guide for more information.

Q. Are there limitations to the capabilities of routed ports?

A. Yes, there are some limitations. A routed port on the EtherSwitch module does not support subinterfaces. Also, routed ports cannot receive an address from a DHCP server. Instead, the static assignment of IP addresses must occur.

Q. What is the earliest Cisco IOS Software release that supports the EtherSwitch modules?

A. Support for the 16-port EtherSwitch NM begins with Cisco IOS Software Release 12.2(2)XT, Plus images only. Support for the 36-port EtherSwitch HDSM begins with Cisco IOS Software Release 12.2(8)T1, Plus images only. This image supports both the 16-port and the 36-port EtherSwitch on Cisco 2600, 3600, and 3700 series platforms. Support for intrachassis stacks begins with Cisco IOS Software Release 12.2(11)T, Plus images only. Support for routed port functionality begins with Cisco IOS Software Releases 12.2(15)ZJ and 12.3(4)T.

Q. Which Cisco IOS Software feature sets support the EtherSwitch modules?

A. In Cisco IOS Software Release 12.2T, the EtherSwitch modules require a Plus feature set. Support for the EtherSwitch modules in the IP Base feature set begins with Cisco IOS Software Release 12.3T.

Q. Do the EtherSwitch modules work with the current Cisco 2600, 3600, and 3700 series WAN interface cards (WICs), voice interface cards (VICs), and NMs?

A. Yes, the EtherSwitch modules work with the current Cisco 2600, 3600, and 3700 WICs, VICs, and NMs.

Q. What features do the EtherSwitch modules support?

A. The EtherSwitch modules support these features:

• VLANs

  • Up to 64 individual VLANs per switch for the Cisco 3660 and 3700 series

• IEEE 802.1Q tagged and untagged VLANs

  • VLAN Trunk Protocol (VTP) support for client, server, and transparent modes

• Layer 2 (L2) MAC-related feature support

  • Secure MAC addresses

  • Static and dynamic MAC addressing

  • 8000 total MAC addresses

• Port application support

  • EtherChannel port aggregation

  • Port monitoring

• Router-based broadcast/multicast/unicast storm control QoS feature support

  • IEEE 802.1p

  • Class of Service (CoS) priority for an 802.1Q tagged frame

  • Port-based priority for native frames

  • Port priority to overwrite the 802.1p priority

  • Strict priority and weighted round-robin (WRR)

• Additional features

  • CoS to differentiated services code point (DSCP) mapping

  • Internet Group Multicast Protocol (IGMP) snooping

  • Network Time Protocol (NTP) support

  • IEEE 802.1D spanning tree and Spanning Tree Protocol (STP) PortFast Simple Network Management Protocol (SNMP) support

  • Telnet client/server support

  • Cisco Discovery Protocol (CDP) version 1 and version 2 support

  • Flow control for the Gigabit Ethernet port only

  • Fallback bridging

  • Routed port IEEE 802.1x authentication

  • Security access control lists (ACLs)

Q. What features do the EtherSwitch modules not support?

A. The EtherSwitch modules do not support these features:

• Layer 3 (L3) switching (which the router performs)

• Dynamic VLAN for an access port

• VLAN Trunk Protocol (VTP) pruning

• Per-port enabling/disabling of unknown multicast and unicast packets

• CGMP client rate-limit

• Cisco Cluster Management Suite (CMS) support

• Cisco Emergency Responder support

• IEEE 802.3af-compliant Power over Ethernet (PoE)

Q. Which IEEE 802.1x features do the EtherSwitch modules support?

A. The EtherSwitch modules support 802.1x authentication per port in Cisco IOS Software Releases 12.2(15)ZJ, 12.3(4)T, and later. This feature allows the module to enable or disable ports on the basis of 802.1x authentication. The modules do not currently support any other 802.1x features.

Q. Does the EtherSwitch channel support a bridge to switched virtual interfaces (SVIs)?

A. With Cisco IOS Software Releases 12.2(15)ZJ and 12.3(4)T, SVIs can become members of bridge groups and perform transparent bridging.

Q. Do the EtherSwitch modules support data-link switching plus (DLSw+)?

A. With Cisco IOS Software Releases 12.2(15)ZJ and 12.3(4)T, the EtherSwitch modules support DLSw+.

Q. What Switched Port Analyzer (SPAN) features do the EtherSwitch modules support?

A. The EtherSwitch modules supports these SPAN features:

• Allowance of one active SPAN session at any given time

• The mirror of all 16/36 ports in one SPAN session

• Allowance of only one destination

• The need for all SPAN ports to be on the same EtherSwitch

• Ability of the module to analyze EtherChannel via SPAN

Q. Do the EtherSwitch modules support Auto Media-Dependent Interface (MDI)/MDI Crossover (MDI-X) detection?

A. No, the configuration of all the Fast Ethernet and Gigabit Ethernet ports is MDI-X. You can only use crossover cables to connect to other MDI-X ports. You can only use straight cables to connect to MDI ports.

Q. What is the maximum number of VLANs that the EtherSwitch modules support?

A. The EtherSwitch module supports up to 32 VLANs for the Cisco 2600, 3620, and 3640 series. The EtherSwitch HDSM supports up to 64 VLANs for the Cisco 3660 and 3700 series.

Q. What is the maximum number of Fast EtherChannels that you can create per EtherSwitch module?

A. You can create a maximum of six Fast EtherChannels per EtherSwitch module. Each Fast EtherChannel can have a maximum of eight ports/interfaces.

Q. What QoS features do the EtherSwitch modules support?

A. The EtherSwitch modules support:

• IEEE 802.1p Class of Service (CoS) priority for IEEE 802.1Q tagged frames

• Port-based priority for native frames

• Port priority to overwrite the 802.1p priority

• Strict priority and weighted round-robin (WRR) CoS policies

Q. Do the EtherSwitch modules support IEEE 802.1x authentication?

A. With Cisco IOS Software Releases 12.2(15)ZJ, 12.3(3)T, and later, the EtherSwitch module supports 802.1x authentication.

Q. How do the 16-port and 36-port EtherSwitch modules receive IP phone power?

A. IP phone power reaches the current Cisco 2600 and 3600 series routers through the external power supply chassis [PWR-Chassis-360W], along with the EtherSwitch module power option [NM-16/36ESW-PWR]. The Cisco 3700 series supports an integrated power supply. No external power supply chassis is necessary with the Cisco 3700 series. However, the same EtherSwitch power option is necessary.

Q. What types of external power supply cables can you get with the 16-port and 36-port EtherSwitch modules?

A. The different types of external power supply cables for the modules are:

• Part number CAB-PPWR-PS1-1—A one-to-one cable that connects one external power supply to one EtherSwitch module. Software monitors the signals "PS1 Present" and "PS1 OK" on this cable and allocates up to 360 W of power for this configuration.

• Part number CAB-PPWR-PS1-2—A two-power-supply-to-one-EtherSwitch-module cable that connects two external power supplies to a single EtherSwitch module. This arrangement provides redundancy in the case that one of the power supplies fails. Software monitors the signals "PS1 Present", "PS1 OK", "PS2 Present", and "PS2 OK" on this cable. Up to 360 W can power this configuration.

• Part number CAB-PPWR-PS2-1—A one-power-supply-to-two-EtherSwitch-module cable that connects one power supply to two different EtherSwitch modules. This cable allows power to two EtherSwitch modules with no redundancy. You must plug the cable into both EtherSwitch modules. The power supply shuts down if you do not plug in either EtherSwitch module or the cable end. The power also shuts down if you do not insert the EtherSwitch modules in a platform. If you unplug one EtherSwitch module, -48 V power to the other EtherSwitch module shuts down. Software monitors a special signal in addition to "PS1 Present" and "PS1 OK" for this configuration. Up to 160 W of power reach each of the two EtherSwitch modules.

Related Information

• Release Notes for the Cisco 3725 and Cisco 3745 Modular Access Routers for Cisco IOS Release 12.2(15)ZJ5
• Cisco IOS Software Releases 12.3T EtherSwitch Network Module
• LAN Product Support Pages
• LAN Switching Support Page
• Technical Support - Cisco Systems