Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the Feature Information Table at the end of this document.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
Prerequisites for Layer 2 Local Switching
You must enable Cisco Express Forwarding for the Cisco 7200 series router. You must use Cisco Express Forwarding or Distributed Cisco Express Forwarding for the Cisco 7500 series router. (Distributed Cisco Express Forwarding is enabled already by default on the Gigabit Switch Router [GSR]).
For Frame Relay local switching, you must globally issue the frame-relayswitchingcommand.
In ATM single cell relay AAL0, the ATM virtual path identifier/virtual channel identifier (VPI/VCI) values must match between the ingress and egress ATM interfaces on the Cisco 7200 series and 7500 series routers. If Layer 2 local switching is desired between two ATM VPIs and VCIs whose values do not match and are on two different interfaces, choose ATM AAL5. However, if the ATM AAL5 is using Operation, Administration, and Maintenance (OAM) transparent mode, the VPI and VCI values must match.
NSF/SSO: Layer 2 local switching is supported on Cisco 7500 series routers.
Layer 2 local switching is supported on the following interface processors in the Cisco 7200 series routers:
C7200-I/O-2FE
C7200-I/O-GE+E (Only the Gigabit Ethernet port of this port adapter is supported.)
C7200-I/O-FE
Layer 2 local switching is supported on the following interface processors in the Cisco 7500 series routers:
All GSR line cards support Frame Relay-to-Frame Relay local switching.
8-port OC-3 ATM Engine 2 line cards support only like-to-like Layer 2 local switching.
IP Service Engine (ISE) (Engine 3) line cards support like-to-like and any-to-any local switching. Non-ISE line cards support only like-to-like local switching.
Starting in Cisco IOS Release 12.0(31)S2, ISE customer edge-facing interfaces support the following types of like-to-like and any-to-any local switching:
ATM to ATM
ATM to Ethernet
ATM to Frame Relay
Ethernet to Ethernet VLAN
Frame Relay to Frame Relay (including Multilink Frame Relay)
Same-port switching for ATM (PVC and PVP)
Same-port switching for Ethernet VLAN
Same-port switching for Frame Relay
Note
Native Layer 2 Tunnel Protocol Version 3 (L2TPv3) tunnel sessions on customer edge-facing line cards can coexist with tunnel sessions that use a tunnel-server card.
Starting in Cisco IOS Release 12.0(32)SY, customer edge-facing interfaces on Engine 5 SPAs and SPA Interface Processors (SIPs) support the following types of like-to-like local switching:
Ethernet to Ethernet VLAN
Frame Relay to Frame Relay (including Multilink Frame Relay)
Same-port switching for Ethernet VLAN
Same-port switching for Frame Relay
For ATM-to-ATM local switching, the following ATM types are supported for the Layer 2 Local Switching feature:
ATM adaptation layer 5 (AAL5)
ATM single cell relay adaptation layer 0 (AAL0), VC mode
ATM single cell relay VP mode on the GSR
ATM single cell relay VC and VP modes on ISE line cards on the GSR
Starting with Cisco IOS Release 12.0(30)S, you can use local switching and cell packing with ATM VP or VC mode on the GSR on IP Services Engine (ISE/Engine 3) line cards. For information about how to configure cell packing, refer to Any Transport over MPLS.
Unsupported Hardware
The following hardware is not supported:
Cisco 7200--non-VXR chassis
Cisco 7500--Route Switch Processor (RSP)1 and 2
Cisco 7500--Versatile Interface Processor (VIP) 2-40 and below
GSR--4-port OC-3 ATM Engine-0 line card
GSR--4-port OC-12 ATM Engine-2 line card
GSR--1-port OC-12 ATM Engine-0 line card
GSR--Ethernet Engine-1, Engine-2, and Engine-4 line cards
Local switching allows you to switch Layer 2 data between two interfaces of the same type (for example, ATM to ATM, or Frame Relay to Frame Relay) or between interfaces of different types (for example, Frame Relay to ATM) on the same router. The interfaces can be on the same line card or on two different cards. During these kinds of switching, the Layer 2 address is used, not any Layer 3 address.
Additionally, same-port local switching allows you to switch Layer 2 data between two circuits on the same interface.
NSF SSO - Local Switching Overview
Nonstop forwarding (NSF) and stateful switchover (SSO) improve the availability of the network by providing redundant Route Processors (RPs) and checkpointing of data to ensure minimal packet loss when the primary RP goes down. NSF/SSO support is available for the following locally switched attachment circuits:
Ethernet to Ethernet VLAN
Frame Relay to Frame Relay
Layer 2 Local Switching Applications
Incumbent local exchange carriers (ILECs) who use an interexchange carrier (IXC) to carry traffic between two local exchange carriers can use the Layer 2 Local Switching feature. Telecom regulations require the ILECs to pay the IXCs to carry that traffic. At times, the ILECs cannot terminate customer connections that are in different local access and transport areas (LATAs). In other cases, customer connections terminate in the same LATA, which may also be on the same router.
For example, company A has more than 50 LATAs across the country and uses three routers for each LATA. Company A uses companies B and C to carry traffic between local exchange carriers. Local switching of Layer 2 frames on the same router might be required.
Similarly, if a router is using, for example, a channelized interface, it might need to switch incoming and outgoing traffic across two logical interfaces that reside on a single physical port. The same-port local switching feature addresses that implementation.
The figure below shows a network that uses local switching for both Frame Relay to Frame Relay and ATM to Frame Relay local switching.
Figure 1
Local Switching Example
Access Circuit Redundancy Local Switching
The Automatic Protection Switching (APS) mechanism provides a switchover time of less than 50 milliseconds. However, the switchover time is longer in a pseudowire configuration due to the time the pseudowire takes to enter the UP state on switchover. The switchover time of the pseudowire can be eliminated if there is a single pseudowire on the working and protect interfaces instead of separate pseudowire configurations. A single pseudowire also eliminates the need to have Label Distribution Protocols (LDP) negotiations on a switchover. The virtual interface or controller model provides a method to configure a single pseudowire between the provider edge (PE) routers.
Access Circuit Redundancy (ACR) ensures low data traffic downtime by reducing the switchover time. ACR works on the APS 1+1, nonrevertive model where each redundant line pair consists of a working line and a protect line. If a signal fail condition or a signal degrade condition is detected, the hardware switches from the working line to the protect line.
The working and protect interfaces can be on the following:
Same SPA
Different SPA but on the same line card
SPAs on different line cards
When the working or protection interface is configured with ACR, a virtual interface is created and a connection is established between the virtual interfaces to facilitate the switching of data between the interfaces.
ACR for ATM-to-ATM local switching supports the ATM AAL5 and ATM AAL0 encapsulation types and switches Layer 2 data between L2 transport virtual circuits (VCs).
Note
The L2 transport VCs must be configured with the same encapsulation type.
The figure below shows the ACR for ATM-to-ATM local switching model.
Figure 2
ATM-to-ATM ACR Local Switching Model
In the figure:
ATM 1/0/0 and ATM 9/0/0 are configured as working and protection interfaces of ACR 1 group.
ATM 7/1/0 and ATM 9/1/0 are configured as working and protection interfaces of ACR 2 group.
A connection is established between the ACRs.
The Add/Drop Multiplexer (ADM) sends data to both the interfaces, which are part of the ACR group ACR 1.
The cells or packets received on the APS active interface VC (0/32) of ACR group 1 are switched to the ACR 2 interface VC (1/32) and the cells or packets from the APS inactive interface are dropped.
The packets received on the ACR 2 VC (1/32) interface are replicated on both the physical interfaces, which are part of the ACR group ACR 2.
ACR for CEM-to-CEM Local Switching
Circuit Emulation (CEM) transports Time Division Multiplexing (TDM) data over TDM pseudowires, allowing mobile operators to carry TDM traffic over an IP or Multiprotocol Label Switching (MPLS) network. ACR for CEM-to-CEM involves creating a virtual controller and associating the virtual controller with the physical controllers. The virtual controller is created when APS and ACR are configured on the physical controller. All commands executed on the virtual controller apply to the working and protect controller. The virtual controller simplifies the single point of configuration and provides the flexibility of not running a backup pseudowire for the protect controller in the event of a failure. This way there is no switchover between the pseudowires, which in turn reduces the recovery time when the physical link fails.
When the CEM group is configured on the virtual controller, a virtual CEM-ACR interface is created and associated with the CEM circuit. ACR creates CEM interfaces and CEM circuits on the physical interfaces that correspond to the physical controllers belonging to the same ACR group.
The figure below shows the ACR for CEM-to-CEM local switching model:
Figure 3
CEM-to-CEM ACR Local Switching Model
In the figure:
Packets are received from the ADM. The packets from the APS inactive interface are dropped and the packets received on the APS active interface are switched.
The packets received on the CEM circuit ID 1 of the APS active interface, which is part of ACR group 1, are switched to the CEM circuit ID 2 of the APS active interface, which is part of ACR group 2.
The packets are duplicated and sent on both the APS active and inactive physical CEM interfaces that are part of ACR group 2.
Configuring ATM-to-ATM PVC Local Switching and Same-Port Switching
You can configure local switching for both ATM AAL5 and ATM AAL0 encapsulation types.
Creating the ATM PVC is not required. If you do not create a PVC, one is created for you. For ATM-to-ATM local switching, the autoprovisioned PVC is given the default encapsulation type AAL0 cell relay.
Note
Starting with Cisco IOS Release 12.0(30)S, you can configure same-port switching following the steps in this section.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfaceatmslot/port
4.pvcvpi/vcil2transport
5.encapsulationlayer-type
6.exit
7.exit
8.connectconnection-nameinterfacepvcinterfacepvc
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfaceatmslot/port
Example:
Router(config)# interface atm1/0/0
Specifies an ATM line card, subslot (if available), and port, and enters interface configuration mode.
Step 4
pvcvpi/vcil2transport
Example:
Router(config-if)# pvc 1/100 l2transport
Assigns a VPI and VCI and enters ATM PVC l2transport configuration mode.
The
l2transport keyword indicates that the PVC is a switched PVC instead of a terminated PVC.
Specifies an ATM line card, subslot (if available), and port, and enters interface configuration mode.
Step 4
atmpvpvpil2transport
Example:
Router(config-if)# atm pvp 100 l2transport
Identifies the virtual path and enters PVP l2transport configuration mode. The l2transportkeyword indicates that the PVP is a switched PVP instead of a terminated PVP.
Repeat Steps 3 and 4 for another ATM permanent virtual path on the same router.
Step 5
exit
Example:
Router(config-if-atm-l2trans-pvp)# exit
Exits PVP l2transport configuration mode and returns to interface configuration mode.
Step 6
exit
Example:
Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
Step 7
connectconnection-nameinterfacepvpinterfacepvp
Example:
Router(config)# connect atm-con
Example:
atm1/0 100 atm2/0 200
In global configuration mode, creates a local connection between the two specified permanent virtual paths.
Configuring ATM PVP Same-Port Switching
Perform this task to configure ATM PVP switching on an ATM interface.
SUMMARY STEPS
1.enable
2.configureterminal
3.interfaceatmslot/subslot/port
4.atmpvpvpil2transport
5.exit
6.exit
7.connectconnection-nameinterfacepvpinterfacepvp
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
interfaceatmslot/subslot/port
Example:
Router(config)# interface atm1/0/0
Specifies an ATM line card, subslot (if available), and port, and enters interface configuration mode.
Step 4
atmpvpvpil2transport
Example:
Router(config-if)# atm pvp 100 l2transport
Specifies one VPI and enters PVP l2transport configuration mode. Repeat this step for the other ATM permanent virtual path on this same port.
The l2transportkeyword indicates that the indicated PVP is a switched PVP instead of a terminated PVP.
Step 5
exit
Example:
Router(config-if-atm-l2trans-pvp)# exit
Exits PVP l2transport configuration mode and returns to interface configuration mode.
Step 6
exit
Example:
Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
In global configuration mode, creates the local connection between the two specified permanent virtual paths.
Configuring ATM-to-Ethernet Port Mode Local Switching
For ATM to Ethernet port mode local switching, creating the ATM PVC is not required. If you do not create a PVC, one is created for you. For ATM-to-Ethernet local switching, the autoprovisioned PVC is given the default encapsulation type AAL5SNAP.
ATM-to-Ethernet local switching supports both the IP and Ethernet interworking types. When the Ethernet interworking type is used, the interworking device (router) expects a bridged packet. Therefore, configure the ATM CPE for either IRB or RBE.
Note
Enabling ICMP Router Discovery Protocol on the Ethernet side is recommended.
ATM-to-Ethernet local switching supports the following encapsulation types:
ATM-to-Ethernet with IP interworking: AAL5SNAP, AAL5MUX
ATM-to-Ethernet with Ethernet interworking: AAL5SNAP
Perform this task to configure local switching between ATM and Ethernet port mode.
In global configuration mode, creates a local connection between the two interfaces and specifies the interworking type.
Both the IP and Ethernet interworking types are supported.
Configuring ATM-to-Ethernet VLAN Mode Local Switching
For ATM-to-Ethernet VLAN mode local switching, creating the ATM PVC is not required. If you do not create a PVC, one is created for you. For ATM-to-Ethernet local switching, the autoprovisioned PVC is given the default encapsulation type AAL5SNAP.
ATM-to-Ethernet local switching supports both the IP and Ethernet interworking types. When the Ethernet interworking type is used, the interworking device (router) expects a bridged packet. Therefore, configure the ATM CPE for either IRB or RBE.
Note
Enabling ICMP Router Discovery Protocol on the Ethernet side is recommended.
ATM-to-Ethernet local switching supports the following encapsulation types:
ATM-to-Ethernet with IP interworking: AAL5SNAP, AAL5MUX
ATM-to-Ethernet with Ethernet interworking: AAL5SNAP
The VLAN header is removed from frames that are received on an Ethernet subinterface.
Perform this task to configure local switching for ATM to Ethernet in VLAN mode.
In global configuration mode, specifies the second Fast Ethernet line card, subslot (if available), port, and subinterface, and enters subinterface configuration mode.
Step 7
encapsulationdot1qvlan-id
Example:
Router(config-subif)# encapsulation dot1q 20
Enables this subinterface to accept 802.1Q VLAN packets and specifies the second VLAN.
Step 8
exit
Example:
Router(config-subif)# exit
Exits subinterface configuration mode and returns to global configuration mode.
In global configuration mode, creates a local connection between the two subinterfaces (and hence their previously specified VLANs) on the same Fast Ethernet port.
Configuring Ethernet Port Mode to Ethernet VLAN Local Switching
Perform this task to configure local switching for Ethernet (port mode) to Ethernet VLAN.
Specifies a Fast Ethernet line card, subslot (if available), and port, and enters interface configuration mode. This is the interface on one side of the PE router that passes Ethernet packets to and from the customer edge (CE) router.
Specifies a Fast Ethernet line card, subslot (if available), port, and subinterface, and enters subinterface configuration mode. This is the interface on the other side of the PE router than passes Ethernet VLAN packets to and from the CE router.
Step 5
encapsulationdot1qvlan-id
Example:
Router(config-subif)# encapsulation dot1q 100
Enables the interface to accept 802.1Q VLAN packets.
Step 6
exit
Example:
Router(config-subif)# exit
Exits subinterface configuration mode and returns to global configuration mode.
Creates a local connection between the two interfaces and specifies the interworking type.
Both the IP and Ethernet interworking types are supported.
Configuring ATM-to-Frame Relay Local Switching
You use the interworkingipkeywords for configuring ATM-to-Frame Relay local switching.
FRF.8 Frame Relay-to-ATM service interworking functionality is not supported. Frame Relay discard-eligible (DE) bits do not get mapped to ATM cell loss priority (CLP) bits, and forward explicit congestion notification (FECN) bits do not get mapped to ATM explicit forward congestion indication (EFCI) bits.
Creating the PVC is not required. If you do not create a PVC, one is created for you. For ATM-to-Ethernet local switching, the automatically provisioned PVC is given the default encapsulation type AAL5SNAP.
ATM-to-Frame Relay local switching supports the following encapsulation types:
AAL5SNAP
AAL5NLPID (GSR uses AAL5MUX instead, for IP interworking)
Perform this task to configure local switching for HDLC. The PE routers are configured with HDLC encapsulation. The CE routers are configured with any HDLC-based encapsulation, including HDLC, PPP, and Frame Relay.
Before You Begin
Ensure that the interfaces you configure for HDLC encapsulation can handle ping packets that are smaller, the same size as, or larger than the CE interface MTU.
Enable Cisco Express Forwarding.
Note
Do not configure other settings on the interfaces configured for HDLC encapsulation. If you assign an IP address on the interface, the connect command is rejected and the following error message displays:
Incompatible with IP address command on interface - command rejected.
If you configure other settings on the interface that is enabled for HDLC encapsulation, the local switching feature may not work.
Interworking is not supported.
Same-port local switching for HDLC is not supported.
Dialer and ISDN interfaces are not supported. Only serial, HSSI, and POS interfaces can be configured for HDLC local switching.
>
SUMMARY STEPS
1.enable
2.configureterminal
3.ipcef
4.interfacetypenumber
5.exit
6.connectconnection-nameinterfaceinterface
DETAILED STEPS
Command or Action
Purpose
Step 1
enable
Example:
Router> enable
Enables privileged EXEC mode.
Enter your password if prompted.
Step 2
configureterminal
Example:
Router# configure terminal
Enters global configuration mode.
Step 3
ipcef
Example:
Router(config)# ip cef
Enables Cisco Express Forwarding operation.
Step 4
interfacetypenumber
Example:
Router(config)# interface serial 2/0
Specifies an interface and enters interface configuration mode.
Step 5
exit
Example:
Router(config-if)# exit
Exits interface configuration mode and returns to global configuration mode.
The connect command provides an infrastructure to create the required L2 transport VCs with the default AAl0 encapsulation type and does not require that the VCs must exist.
Perform this task to configure ACR for ATM-to-ATM local switching.
To verify configuration of the Layer 2 Local Switching feature, use the following commands on the provider edge (PE) router:
SUMMARY STEPS
1.showconnection [all | element | idid | namename | portport]
2.showatmpvc
3.showframe-relaypvc[pvc]
DETAILED STEPS
Step 1
showconnection [all | element | idid | namename | portport]
The showconnectioncommand displays the local connection between an ATM interface and a Fast Ethernet interface:
Example:
Router# show connection name atm-eth-con
ID Name Segment 1 Segment 2 State
==================================================================
1 atm-eth-con ATM0/0/0 AAL5 0/100 FastEthernet6/0/0 UP
This example displays the local connection between an ATM interface and a serial interface:
Example:
Router# show connection name atm-fr-con
ID Name Segment 1 Segment 2 State
==================================================================
1 atm-fr-con ATM0/0/0 AAL5 0/100 Serial1/0/0 16 UP
This example displays a same-port connection on a serial interface.
Example:
Router# show connection name same-port
ID Name Segment 1 Segment 2 State
==================================================================
1 same-port Serial1/1/1 101 Serial1/1/1 102 UP
Step 2
showatmpvc
The showatmpvccommand shows that interface ATM3/0 is UP:
Example:
Router# show atm pvc
VCD/ Peak Avg/Min Burst
Interface Name VPI VCI Type Encaps SC Kbps Kbps Cells Sts
3/0 10 1 32 PVC FRATMSRV UBR 155000 UP
Step 3
showframe-relaypvc[pvc]
The showframe-relaypvc command shows a switched Frame Relay PVC:
Example:
Router# show frame-relay pvc 16
PVC Statistics for interface POS5/0 (Frame Relay NNI)
DLCI = 16, DLCI USAGE = SWITCHED, PVC STATUS = UP, INTERFACE = POS5/0
LOCAL PVC STATUS = UP, NNI PVC STATUS = ACTIVE
input pkts 0 output pkts 0 in bytes 0
out bytes 0 dropped pkts 100 in FECN pkts 0
in BECN pkts 0 out FECN pkts 0 out BECN pkts 0
in DE pkts 0 out DE pkts 0
out bcast pkts 0 out bcast bytes 0
switched pkts 0
Detailed packet drop counters:
no out intf 0 out intf down 100 no out PVC 0
in PVC down 0 out PVC down 0 pkt too big 0
pvc create time 00:25:32, last time pvc status changed 00:06:31
Verifying the NSF SSO Local Switching Configuration
Layer 2 local switching provides NSF/SSO support for Local Switching of the following attachment circuits on the same router:
Ethernet (port mode) to Ethernet VLAN
Frame Relay to Frame Relay
For information about configuring NSF/SSO on the RPs, see the Stateful Switchover feature module. To verify that the NSF/SSO: Layer 2 Local Switching is working correctly, follow the steps in this section.
SUMMARY STEPS
1. Issue thepingcommand or initiate traffic between the two CE routers.
2. Force the switchover from the active RP to the standby RP by using the
redundancyforce-switchover command. This manual procedure allows for a "graceful" or controlled shutdown of the active RP and switchover to the standby RP. This graceful shutdown allows critical cleanup to occur.
3. Issue theshowconnectallcommand to ensure that the Layer 2 local switching connection on the dual RP is operating.
4. Issue the
ping command from the CE router to verify that the contiguous packet outage was minimal during the switchover.
DETAILED STEPS
Step 1
Issue thepingcommand or initiate traffic between the two CE routers.
Step 2
Force the switchover from the active RP to the standby RP by using the
redundancyforce-switchover command. This manual procedure allows for a "graceful" or controlled shutdown of the active RP and switchover to the standby RP. This graceful shutdown allows critical cleanup to occur.
Step 3
Issue theshowconnectallcommand to ensure that the Layer 2 local switching connection on the dual RP is operating.
Example:
Router# show connect all
ID Name Segment 1 Segment 2 State
2 Eth-Vlan1 Fa1/1/1 Fa6/0/0/0.1 UP
Step 4
Issue the
ping command from the CE router to verify that the contiguous packet outage was minimal during the switchover.
Troubleshooting Tips
You can troubleshoot Layer 2 local switching using the following commands on the PE router:
debugatml2transport
debugconn
debugframe-relaypseudowire
showframe-relaypvc
showconnection
showatmpvc
Configuration Examples for Layer 2 Local Switching
ATM-to-Ethernet local switching terminates an ATM frame to an Ethernet/VLAN frame over the same PE router. Two interworking models are used: Ethernet mode and IP mode.
The following example shows an Ethernet interface configured for Ethernet VLAN, and an ATM PVC interface configured for AAL5 encapsulation. The connectcommand allows local switching between these two interfaces and specifies the interworking type as Ethernet mode.
The following example shows an Ethernet interface configured for Ethernet and an ATM interface configured for AAL5SNAP encapsulation. The connectcommand allows local switching between these two interfaces and specifies the interworking type as IP mode.
The following example shows a serial interface configured for Frame Relay and an ATM interface configured for AAL5SNAP encapsulation. The connectcommand allows local switching between these two interfaces.
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The following table provides release information about the feature or features described in this module. This table lists only the software release that introduced support for a given feature in a given software release train. Unless noted otherwise, subsequent releases of that software release train also support that feature.
Use Cisco Feature Navigator to find information about platform support and Cisco software image support. To access Cisco Feature Navigator, go to
www.cisco.com/go/cfn. An account on Cisco.com is not required.
The Layer 2 Local Switching feature allows you to switch Layer 2 data between two interfaces on the same router, and in some cases to switch Layer 2 data between two circuits on the same interface port.
The feature was introduced in Cisco IOS Release 12.0(27)S on the Cisco 7200 and 7500 series routers.
The feature was integrated into Cisco IOS Release 12.2(25)S for the Cisco 7500 series router.
In Cisco IOS Release 12.0(30)S, support for same-port switching was added. Support for Layer 2 interface-to-interface local switching was added on the GSR.
In Cisco IOS Release 12.0(31)S2, support was added for customer edge-facing IP Service Engine (ISE) interfaces on the GSR.
In Cisco IOS Release 12.0(32)SY, support was added for customer edge-facing interfaces on Engine 5 shared port adapters (SPAs) and SPA Interface Processors (SIPs) on the GSR.
In Cisco IOS Release 12.2(28)SB, this feature was updated to include NSF/SSO support on the Cisco 7500 series routers for the following local switching types on nonstop forwarding/stateful switchover (NSF/SSO):
NSF/SSO--Ethernet-to-Ethernet VLAN local switching support
NSF/SSO--Frame Relay-to-Frame Relay local switching support
In Cisco IOS Release 12.4(11)T, support was added for the following local switching types for the Cisco 7200 series router:
Ethernet to Ethernet VLAN
Same-port switching for Ethernet VLAN
Frame Relay to Frame Relay
Same-port switching for Frame Relay
In Cisco IOS Release 12.2(28)SB, supported was added for Local Switching on the Cisco 10000 series router.
In Cisco IOS Release 12.2(33)SXH, support was added for like-to-like Local Switching (ATM to ATM, and FR to FR only) on Cisco 6500 series switches and Cisco 7600 series routers. Same-port switching is not supported on those routers.
In Cisco IOS Release 12.2(33)SB, support was added for HDLC Local Switching on the Cisco 7200 series router and the Cisco 10000 series router.
The following commands were introduced or modified:
connect(L2VPN local switching),
encapsulation (Layer 2 local switching),
showconnection.
Access Circuit Redundancy for ATM Local Switching
15.1(1)S
Access Circuit Redundancy (ACR) ensures low data traffic downtime by reducing the switchover time. ACR works on the APS 1+1, nonrevertive model where each redundant line pair consists of a working line and a protect line. If a signal fail condition or a signal degrade condition is detected, the hardware switches from the working line to the protect line.
In Cisco IOS Release 15.1(1)S, this feature was introduced.
The following commands were introduced or modified:
apsgroup,
connect (L2VPN local switching).
ACR support for CEM
15.1(1)S
This feature provides Access Circuit Redundancy (ACR) support for CEM.
In Cisco IOS Release 15.1(1)S, this feature was introduced.
The following commands were introduced or modified:
apsgroup,
connect(L2VPN local switching).
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