Cisco® Catalyst® Instant Access simplifies the design and deployment of the traditional enterprise network architecture. It creates a single network touchpoint and single configuration across distribution and access-layer switches, fostering simplified operations and consistent features across distribution and access and ultimately helping reduce the total cost of ownership (TCO).
This document addresses some of the frequently asked questions.
Q. Is the Cisco Catalyst Instant Access solution similar to the Cisco Nexus
® Fabric Extender (FEX) solution?
A. The Cisco Catalyst Instant Access solution is very similar to data center FEX, with a consistent command-line interface (CLI) across the two solutions. The primary difference is that Instant Access is customized to meet the enterprise campus network needs with features more relevant to campus networks such as stacking, Power over Ethernet/Power over Ethernet Plus (PoE/PoE+), support for remote switches, Security Group Tagging (SGT), Multiprotocol Label Switching (MPLS) at access, Easy Virtual Network (EVN), and so on.
Q. What are the different components of the Instant Access solution?
The Instant Access solution requires new Cisco Catalyst 6800ia Instant Access clients and Cisco Catalyst 6500 or 6800 Series Switches (Instant Access parents) with
Supervisor Engine 2T
line cards. Instant Access requires Cisco Catalyst 6500 or 6800 Series Switches configured for Virtual Switching System (VSS) mode, and we recommended having a pair of switches to provide the maximum level of redundancy and load balancing.
In networks where a pair of Cisco Catalyst 6500/6800 is not available, a single Cisco Catalyst 6500/6800 switch may be used when configured for VSS mode.
Q. What release number will support Instant Access?
A. Cisco IOS
® Software 15.1(2)SY and later versions on the Cisco Catalyst 6500 and 6800 Series.
Q. Is a special software license required for Instant Access?
A. The Instant Access solution is supported with the IP Services feature set on the Cisco Catalyst 6500/6800 and does not require any additional licenses.
Q. How many ports can we deploy in a single Instant Access domain?
A. When first shipped, an Instant Access parent can support up to 1000 host ports across 21 Instant Access clients.
Note: Newer code versions will scale the number of clients and ports higher, so check the latest software release notes for these numbers.
Q. How many Instant Access clients can an Instant Access parent support?
A. When first shipped, the Instant Access parent can support up to 21 Instant Access clients distributed over a maximum of 12 Instant Access stack IDs (FEX IDs).
Note: Newer code versions will scale the number of clients and ports higher, so check the latest software release notes for these numbers.
Q. How many 10Gbps uplinks can be bundled in a single fex-fabric Multichassis EtherChannel (MEC) from Instant Access client stack to Instant Access parent?
A. When first shipped, up to six 10Gbps uplinks can be bundled (two 10Gbps uplinks per stack member) from Instant Access client stack to Instant Access parent.
Q. Can an Instant Access client dual-home to two different 6904-10G line cards over a fex-fabric MEC link?
A. Yes, the fabric links can span across multiple 6904-10G line cards in either a single Cisco Catalyst 6500/6800 chassis or across the VSS, providing line card-level redundancy at the Instant Access parent.
Q. What is the distance limitation between the Instant Access parent and the Instant Access client?
A. The fabric links are based on 10 Gigabit Ethernet links between the parent and the client. The only distance limitation is based on the transceivers (and related cables) used. For information about optics supported, refer to the next question.
Q. What transceivers are supported between Instant Access client and parent 10Gbps fex-fabric links?
The Cisco Catalyst 6800IA has two 10 Gigabit Ethernet uplink ports, which support Short-Reach (SR), Long-Reach (LR), Long-Reach Multimode (LRM), and Extend-Reach (ER) Small Form-Factor Pluggable Plus (SFP+) transceivers and associated MMF or SMF fiber cables, as well as 1M, 3M, and 5M copper Twinax cables. The Cisco-FET-10G is not supported in the Instant Access solution. Refer to the transceiver compatibility data sheet for more details at
10 Gigabit Ethernet Transceiver Modules Compatibility Matrix
Q. How many Instant Access clients can be stacked, and what is the stacking bandwidth?
A. When first shipped, the Instant Access solution supports a stack of up to three Instant Access clients with bidirectional stack bandwidth of 80Gbps.
Note: Newer code versions will scale the number of stack members (and uplink ports) higher, so check the latest software release notes for these numbers.
Q. Is the stacking module included with the Instant Access client? Does it need to be purchased separately?
A. The stacking module is built in and included when ordering the Instant Access client.
Q. Does Instant Access client support dual power supplies to support IP phone deployments?
A. Yes, 6800IA-FPDR is the Instant Access client SKU with onboard redundant power supply. Additionally, RPS2300 as external redundant power supply is supported on all C6800 Instant Access clients.
Q. Does the Cisco Catalyst 6800ia Instant Access client support Cisco StackPower
A. No, the Cisco Catalyst 6800ia does not support Cisco StackPower.
Q. Can the Instant Access solution and a traditional campus deployment coexist in the same Cisco Catalyst 6500/6800 VSS at distribution?
A. Yes, both traditional network deployments (that is, Cisco Catalyst 2k/3k/4k access switches and the Instant Access solution with Cisco Catalyst 6800IA) can coexist when connected to a single Cisco Catalyst 6500/6800 VSS at the distribution, using the existing Supervisor Engine 2T and WS-X6904-40G/10G line cards, thus providing true investment protection.
Q. Can some ports of the WS-X6904-40G/10G line card be used for the Instant Access solution and other ports used for traditional network trunk and or IP routed access?
A. Yes, the WS-6904-40G/10G line card can support Instant Access (fex-fabric link) connectivity to a Cisco Catalyst 6800IA simultaneously with the traditional Layer 2/Layer 3 connectivity to Cisco Catalyst 2k/3k/4k switches. The line card can operate in 1G, 10G, and 40G mode simultaneously, with some port groups configured in 40Gbps mode and others in 10Gbps mode, enabling different solutions to coexist.
Q. Does the 6800IA uplink support 1G SFP instead of 10G SFP+?
A. Yes, with the Cisco IOS Software 15.1(2)SY2 release we are supporting 1G SFP uplinks on 6800IA as well, but for proper oversubscription we recommend using 10G uplinks.
Q. Can a compact switch be connected to an Instant Access client?
A. Yes, a compact switch, or any other switch, can be connected to an Instant Access client host port.
Note: Any remote connected switches will be independently managed and not part of the Instant Access domain.
Q. Does the Cisco Catalyst 6800IA support PoE and PoE+?
Yes, the Cisco Catalyst 6800IA-48FPD and 48FPDR modules support PoE (15W) on all 48 10/100/1000-TX ports and PoE+ (30W) on any 24 of the 10/100/1000-TX ports, or a combination thereof, with a maximum PoE budget of 740W. Refer to the
Cisco Catalyst 6800ia data sheet
for more details and a complete list of capabilities.
Q. Can wireless access points be directly connected to an Instant Access client?
A. Yes, access points can be directly connected to Instant Access clients and powered by the PoE/PoE+ capabilities of the Instant Access client.
Q. Can the 6908-10G line card be used for 10G fabric link termination at the Instant Access parent?
A. No, the 6908-10G does not support VNTAG capability in hardware to support the Instant Access solution.
Q. Can the existing Cisco Catalyst 2960S/2960X switches be used as Instant Access clients?
A. No, the existing Cisco Catalyst 2960S/2960X does not have hardware capability to support the Instant Access solution.
Q. Can the Instant Access client be configured to operate as a standalone switch in non-FEX mode?
A. No, the Cisco Catalyst 6800ia can only operate in Instant Access client mode and does not support any local switching.
Q. Does Instant Access support EtherChannel with multiple host ports on a single Cisco Catalyst 6800IA?
A. Yes. Cisco IOS Software Release 15.1(2)SY2 supports up to 2 Instant Access host ports per port channel on a single Instant Access client, either a single client or the same Instant Access stack. A total of 23 host port channels are supported per stack.
Q. Does Instant Access support MEC across multiple Cisco Catalyst 6800IAs?
A. No. MEC across multiple Instant Access clients (that is, multiple different FEX IDs) is not supported.
Q. What is the oversubscription on the Cisco Catalyst 6800IA?
A. Each Cisco Catalyst 6800IA supports 48 10/100/1000-TX host ports and two 10Gbps uplinks, offering a subscription ration of 2.4:1 (48/20) across the fex-fabric links to the Instant Access parent.
Note: All forwarding decisions are made on the Instant Access parent (Cisco Catalyst 6500/6800).
Q. Will there be local switching on the Instant Access Cisco Catalyst 6800IA?
The Cisco Catalyst 6800IA does not support any local switching. All the Layer 2 switching, MPLS, and Layer 3 routing happens on the Instant Access parent. Because all the forwarding decisions are made on the Instant Access parent (Cisco Catalyst 6500/6800), we can now use the breadth of features available in these platforms all the way down the access layer. For more details about packet walks, refer to the
Instant Access white paper
Q. Will there be local multicast replication on the Instant Access Cisco Catalyst 6800IA?
A. The Cisco Catalyst 6800IA supports local Layer 2 (that is, within the same VLAN) replication of multicast flows to allow for a scalable, distributed multicast solution. While multicast lookups are performed on the Instant Access parent, the replication of the multicast flows destined for the host on that particular Instant Access client occurs locally on the Instant Access client.
Q. How does the traffic flow between two hosts directly connected to Instant Access clients?
Host-to-host traffic flows through the Instant Access parent. The actual forwarding of packets happens at the distributed forwarding engine (DFC4) in the 6904-10G line card at the Instant Access parent. For more details on packet walk, refer to the
Instant Access white paper
Q. How exactly does the Instant Access client communicate with the Instant Access parent?
A. Instant Access client and parent communicate over four control protocols: Satellite Discovery Protocol (SDP), Satellite Registration Protocol (SRP), Switch Configuration Protocol (SCP), and Inter-Process Communication and Inter-Card Communication (IPC/ICC). SDP and SRP are new protocols that manage the automatic discovery and registration of new Instant Access clients, whereas SCP and IPC/ICC are the same protocols used by the Cisco Catalyst 6500/6800 to manage installation and programming of modular line cards. These are at the heart of the Instant Access solution, enabling automatic provisioning and a single point of management for distribution and access layers. For more information, refer to the Instant Access white paper.
Q. How are new Instant Access clients provisioned? Must any configuration and image upgrade be done at the Instant Access client?
A. Instant Access clients are provisioned automatically when they are connected to an Instant Access parent. The Instant Access parent automatically does an image check on the newly connected Instant Access client. If the Instant Access client image is different from the image on the Instant Access parent, the Instant Access client is automatically upgraded with the newer Instant Access client image. Instant Access client uplinks are also configured automatically by the control protocols running between Instant Access parent and Instant Access client, thus making the access layer truly plug and play. Additionally, Instant Access client stack members are automatically provisioned when connected.
Q. What effect does the Instant Access control protocol between Instant Access parent and client have on the fex-fabric MEC links?
A. The control protocol between Instant Access parent and Instant Access client is lightweight. Four control protocols run between Instant Access parent and Instant Access client:
● Satellite Discovery Protocol (SDP) maintains the heartbeat connection between parent and client and is sent every 3 seconds, with a dead interval of 30 seconds.
● Satellite Registration Protocol (SRP) is nonperiodic and is engaged only when the Instant Access client boots up to provision an Instant Access client.
● Switch Control Protocol (SCP) maintains host port counters and sequences numbers on a transactional basis.
● Inter-Process Communication and Inter-Card Communication (IPC/ICC) also provide transactional traffic for PoE and syslog and do not add any periodic traffic overhead.
Q. What is the code upgrade process for an Instant Access client?
The Instant Access solution supports Enhanced Fast Software Upgrade (
), using the In-Service Software Upgrade (ISSU) software infrastructure. An additional CLI is introduced (
issu runversion [fex [range] <num> | all>]
) to allow upgrade of Instant Access clients during the eFSU process. It supports the capability to do rolling upgrade of all Instant Access clients or do it one at a time.
Q. What are the different states of Instant Access client in the ISSU process?
A. Table 1 lists all the states of Instant Access client in the ISSU process.
Table 1. Instant Access Client States in ISSU Process
FEX is in offline state or not considered as a part of ISSU upgrade.
FEX will be considered as a part of ISSU upgrade.
Image download initiated for FEX. FEX will start image download and extraction of downloaded tar image and rebooting with V2 image.
FEX is successfully upgraded to V2.
FEX boot variable set to V1 image and issued reload for FEX.
Failed to upgrade to V2 image from V1 image.
FEX is already running with V2 image.
FEX is in offline state. FEX controller will notify the abort version to FEX after FEX is back online. FEX controller will move the state to FEX_ABORTVERSION_INPROGRESS.
FEX is successfully moved back to V1.
Q. Will Cisco Prime
™ infrastructure support the Instant Access solution?
A. Yes, Cisco Prime infrastructure 2.0 provides partial support of Instant Access, including list of interfaces, viewing port configuration and status of interfaces, list of Instant Access clients, performance of interfaces, interfaces utilization graph, and many other day-two management capabilities. Instant Access client provisioning, image management, and VSS will be supported in future releases of Cisco Prime infrastructure.
Q. What features are supported at Cisco Catalyst 6800IA client host ports?
A. The Instant Access solution brings Cisco Catalyst 6500/6800 features to the access layer. These include, but are not limited to, features such as:
● Layer 2: Spanning Tree, VLAN Trunking Protocol (VTP), Multiprotocol Label Switching (Port Aggregation Protocol (PAgP), Link Aggregation Protocol (LACP, Cisco Discovery Protocol (CDP), Link Layer Discovery Protocol (LLDP), and Advanced Virtual Private LAN Services (A-VPLS)
● Layer 3: IPv4, IPv6, IP multicast, Easy Virtual Network (EVN), Virtual Routing and Forwarding (e.g. VRF-lite), Multi-Protocol Label Switching (MPLS), Generic Routing Encapsulation (GRE), and Medianet
● Security: 802.1x, Web-Auth, MAB, Security Group Tagging, Security Group Access List, ACL
● Network monitoring: Flexible NetFlow, SPAN/RSPAN/ERSPAN, Embedded Event Manager (EEM)
Q. Does the Instant Access solution have restrictions on the routing protocols we can use?
A. All routing protocols supported on an Instant Access parent can be enabled on the Instant Access client host ports. Cisco Catalyst 6500/6800 with Supervisor 2T supports all routing protocols, and all of them are supported at the Instant Access client as well.
Note: The Instant Access client host ports default to Layer 2 switchports and require a “no switchport” to configure Layer 3 features. All the Layer 3 routing configuration and controls happen at the Instant Access parent (refer to the Instant Access white paper for more details), thereby further simplifying the deployment of Layer 3 routed access with the Instant Access solution.
Q. Why is the default configuration of Instant Access client host port configuration “switch trunk allowed vlan 1” and not “all”?
A. Each Instant Access host port can be configured in access or trunk (default is dynamic). If in trunk mode, there is a constraint as to how many VLANs can be trunked on each port.
Note: No more than 1000 VLANs can be associated to a FEX ID. To make sure that constraint is followed, implementation requires specifying explicitly which VLANs will be trunked, thus making sure not all 4k VLANs are trunked.
Q. Can we support services modules together with the Instant Access solution?
A. Yes, services modules can be deployed in the Instant Access parent (Cisco Catalyst 6500/6800).
Q. What is the purpose of the Instant Access management and console ports?
A. The console and out-of-band management ports are not required for Instant Access client operations on a day-to-day basis because the client provisioning happens automatically. However, these ports allow TAC engineers an extra level of troubleshooting.
Q. What are the power supply rating and heat dissipation of C6800IA Instant Access clients?
The power supply rating for C6800IA-48FPD (POE+) is 100V-240V with current at 9A-4A, frequency at 50Hz-60Hz, with power consumption of 149W, 508 BTU per hour. C6800IA-48TD (non-PoE) power rating is 100V-240V with current at 0.5A-1A, frequency at 50Hz-60Hz, with power consumption of 47W at 161 BTU per hour. For more information, refer to
C6800IA hardware details
Q. Is it required to have two C6k switches in VSS mode as Instant Access parent, or can one switch be used as Instant Access parent?
A. It is recommended to have two switches (a pair of Cisco Catalyst 6500E or C6807 or C6880-X) configured in VSS mode as Instant Access parent. It provides high availability (HA), which is critical for Instant Access clients. However, a single Cisco Catalyst 6500E or C6807 with Supervisor 2T or C6880-X can be used as Instant Access parent when configured in VSS mode (without physical redundancy of second switch). Instant Access technology uses VSS software code infrastructure to treat remote Instant Access clients as remote line cards, hence the need to enable VSS mode in single switch at distribution acting as Instant Access parent.
Q. Is VSS Quad Sup supported with Instant Access?
A. Cisco IOS Software Release 15.1(2)SY2 provides VSS Quad Sup support with Instant Access.
Q. Is quality of service (QoS) supported over fex-fabric MEC uplinks?
The Instant Access solution uses a trust differentiated services code point/class of service (DSCP/CoS) model between the Instant Access client and the Instant Access parent. The frame’s original DSCP/CoS values are maintained, and the frame is queued for transmission over the fabric link according to its DSCP/CoS markings. The DSCP/CoS to queue table maps are configured by default in both the Instant Access client and Instant Access parent and cannot be changed. All control traffic is treated as high-priority traffic. For more details, refer to the
Cisco Catalyst Instant Access white paper
Q. What are the QoS capabilities of the Instant Access solution?
A. Instant Access host ports and fex-fabric uplink ports operate in trust-DSCP mode with no packet modification. C6800IA client supports 4 queues: 1 priority and 3 standard (1P3Q3T) queues for C6800IA host ports and 10G fabric uplinks toward Instant Access parent. A packet already marked with DSCP will be queued based on default table-map preconfigured as shown in the following output and queued into priority or standard queue based on its DSCP marking:
Switch1#show queuing interface gigabitEthernet 122/1/0/43
queuing strategy: Weighted Round-Robin
Queuing on Gi122/1/0/43: Tx Enabled Rx Disabled
Queuing Mode In Tx direction: mode-dscp
Transmit queues [type =
Queue Id Scheduling Num of thresholds
1 Priority 3
2,3,4 WRR 3
WRR bandwidth ratios: 100[queue 1] 100[queue 2] 100[queue 3]
queue-limit ratios: 20[Pri Queue] 15[queue 2] 25[queue 3] 40[queue 4]
queue thresh dscp-map
1 3 32 33 40 41 42 43 44 45 46 47
2 1 16 17 18 19 20 21 22 23 26 27 28 29 30 31 34 35 36 37 38 39
2 2 24
2 3 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63
3 1 25
3 3 0 1 2 3 4 5 6 7
4 1 8 9 11 13 15
4 2 10 12 14
Q. How much packet buffer is available on 6800IA ports?
A. 6800IA supports 4 MB of shared buffers across all ports.