The new Cisco Catalyst 9300, 9400, and 9500 Series Switches are the next generation in the legendary Cisco Catalyst family of enterprise LAN access, aggregation, and core switches. Designed for an entirely new era in networking, the Cisco Catalyst 9000 family delivers high performance and functionality and extends Cisco’s networking leadership with breakthrough innovations in security, mobility, Internet of Things (IoT), and the cloud.
This document is intended to help network planners and engineers who are familiar with the Cisco Catalyst 4500-X Series in deploying Cisco Catalyst 9500 Series Switches in the enterprise networking environment.Why migrate?The Cisco Catalyst 9500 Series Switches are the next generation of enterprise-class switches, built for security, IoT, mobility, and cloud. They leverage the strengths of the Cisco Unified Access® Data Plane (UADP) application-specific integrated circuit (ASIC). With the new UADP 2.0 ASIC, the Cisco Catalyst
9000 switch family delivers twice the performance with comparable pricing while adding a host of new features and functionality.
Cisco Catalyst 9500 Series Switches also combine a new onboard x86-based CPU with the open Cisco IOS® XE Software, a converged operating system. Together they deliver model-driven programmability, streaming telemetry, third-party container-based app hosting, application visibility, stronger security, support for higher-bandwidth uplinks, and a more advanced operating system than the current Cisco Catalyst 4500-X Series offers.
Cisco Catalyst 9500 Series advantagesThe Cisco Catalyst 9500 Series is the industry’s first purpose-built 40-Gbps fixed-core/aggregation enterprise switching platform targeted for the enterprise campus, delivering exceptional table scales and buffering for enterprise applications. The platform offers nonblocking 40-Gbps and 10-Gbps switches with granular port densities that meet diverse campus needs. The Cisco Catalyst 9500 Series supports advanced routing and infrastructure services, Software-Defined Access (SD-Access) border capabilities, and network system virtualization with StackWise® virtual technology, which are critical for its placement in the campus core. The platform also supports all the foundational high-availability capabilities such as patching, graceful insertion and removal (GIR), nonstop forwarding with stateful switchover (NSF/SSO), redundant platinum-rated power supplies, and fans.
System hardwareThe Cisco Catalyst 9500 Series is based on Cisco’s UADP 2.0 ASIC architecture and an x86 CPU architecture. It also provides the option for additional internal and external storage, which enables the device to host containers and run third-party applications and scripts natively within the switch. Table 1 compares the hardware of the 4500-X and 9500 Series.
Table1. Hardware comparison | 4500-X Series | 9500 Series |
| CPU | Dual core 1.5 GHz | Quad core x86 2.4 GHz |
| Memory | 4 GB | 16 GB |
| Internal flash | 16 GB | 16 GB |
| External storage | 16 GB | 120 GB |
System default behaviorsThe system default behaviors on the Cisco Catalyst 9500 Series are very similar to those of the 4500-X Series. For example, interfaces are default in Layer 2 switch port mode, the management interface is in a dedicated virtual routing and forwarding (VRF) instance, and so on. However, there are also some differences:
Control Plane Policing (CoPP): CoPP is enabled on the Cisco Catalyst 9500 Series, with default policing rates for different classes of traffic. These policing rates are optimized for a typical campus environment. The policing rates can be changed or disabled to meet the requirements of different application environments. On the Cisco Catalyst 4500-X Series, CoPP is not enabled by default, but the system provides a macro to create the different classes.
Link-status logging: The logging for link-status changes is on by default with the Cisco Catalyst 9500 Series, and the behavior can be changed per interface. On the 4500-X Series, the logging for link-status changes is off by default and can be changed globally. See Table 2.
Table2. Link-status logging comparison | 4500-X Series | 9500 Series |
| Default | Off | On |
| Configuration | Per system
C4500(config)#no logging
event link-status global
C4500(config)#logging event
link-status global | Per interface
C9500(config)#int te 1/0/1
C9500(config-if)#no logging
event link-status
C9500(config-if)#logging
event link-status |
ROMMON and config-registerThe Cisco Catalyst 9500 Series uses the x86 CPU architecture to enable hosting containers and third-party applications. With this change, there are also changes in the ROMMON.
Prompts and file systemsOn the Cisco Catalyst 4500-X Series, the prompt is “rommon>” and the “bootflash:” is the memory partition for local storage. The prompt on the Cisco Catalyst 9500 Series is “switch:” and the “flash:” is the memory partition for local storage. See
Table3.
Table3. ROMMON outputs
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Boot variablesThe Cisco Catalyst 4500-X Series uses the traditional “config-register” command in both Cisco IOS and ROMMON to control the booting behavior. The Cisco Catalyst 9500 Series uses a parallel set of commands in Cisco IOS XE, which creates the equivalent ROMMON variables. See
Table4.
Table4. Boot variables
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Baud rate With the Cisco Catalyst 9500 Series, the user can set the baud rate in the Cisco IOS XE command-line interface (CLI) or ROMMON. See Table 5.
Table5. Setting the baud rate
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Cisco IOS Software | Confreg 0x????
or
Line con 0
Speed 9600 | Line con 0
Speed 9600 |
| ROMMON | Confreg
Use the interactive prompt to set the baud rate | BAUD=9600 |
“Break” processing At the beginning of the bootup process, the user can use Ctrl+C to break out of the booting process and drop the system back into ROMMON if the break sequence is enabled. See Table6.
Table6.“Break” processing
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Cisco IOS Software | Confreg 0x???? | [no] boot enable-break |
| ROMMON | Confreg
Use the interactive prompt to enable/disable break | ENABLE_BREAK=[no | yes] |
Ignoring the startup configuration With the Cisco Catalyst 9500 Series, the user can ignore the startup configuration in the Cisco IOS XE CLI or ROMMON. (See
Table7.)
Table7. Ignoring the startup configuration
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Cisco IOS Software | Confreg 0x8000 or 0x0040 | C9500-40X(config)#system ignore startupconfig switch 1 |
| ROMMON | Confreg
Use the interactive prompt to enable/disable ignore startup
configuration | SWITCH_IGNORE_STARTUP_CFG=1 |
Operations Interface reference The Cisco Catalyst 4500-X Series has two levels of interface numbering:
interface <Type><Slot#>/<Port#>. The 9500 Series has three levels:
interface <Type><Switch#>/<Module#>/ <Port#>. For example, Ten Gigabit Ethernet port 1 on slot 1 is referenced as: Te1/1 in the 4500-X Series and as Te1/0/1 in the 9500 Series.
In VSS mode on the 4500-X Series, interface numbering is
interface <Type><Switch#>/<Slot#>/<Port#>. In StackWise Virtual mode on the 9500 Series, interface numbering is the same as the single-chassis default interface:
interface <Type><Switch#>/<Module#>/<Port#>. See Table 8.
Table8. Interface numbering
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Default interfaces | TenGigabitEthernet1/1
TenGigabitEthernet1/2 TenGigabitEthernet1/3 | Te1/0/1
Te1/0/2
Te1/0/3 |
| Uplinks | TenGigabitEthernet2/1
TenGigabitEthernet2/2 TenGigabitEthernet2/3 | Te1/1/1
Te1/1/2
Te1/1/3 |
| VSS/StackWise | TenGigabitEthernet1/1/1 for Chassis 1 TenGigabitEthernet2/1/1 for Chassis 2 | Te1/0/1 for Chassis 1 Te2/0/1 for Chassis 2 |
Management interface With the Cisco Catalyst 9500 Series, ‘Gig 0/0’ is used as the management interface and ‘Mgmt-vrf’ as the management VRF. Please be aware that the VRF name is case sensitive. See Table 9.
Table9. Management interface and VRF
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Interface | FastEthernet1 | GigabitEthernet 0/0 |
| VRF | mgmtVrf
C4500-X#sh run int fastEthernet 1
Building configuration... Current configuration : 119 bytes !
interface FastEthernet1 vrf forwarding mgmtVrf ip address 172.26.100.8 255.255.255.0
end | Mgmt-vrf
C9500-40X#sh run int
gigabitEthernet 0/0
Building configuration...
Current configuration : 106 bytes !
interface GigabitEthernet0/0 vrf forwarding Mgmt-vrf ip address 172.26.100.8
255.255.255.0
end |
Software features For details on the software features supported on the Cisco Catalyst 9500 Series, please use the feature navigator on Cisco.com. Some of the features behave differently on the 9500 Series compared to the 4500-X Series. Following are some of these differences. System MTU On the Cisco Catalyst 4500-X Series, the global command “system mtu <1500-1552>” sets the global baby giant MTU for all interfaces. The 4500-X Series also supports per-interface MTU. The per‑interface MTU command takes precedence. With the Cisco Catalyst 9500 Series, the system MTU is a global command that sets the MTU for all the interfaces. See Table 10.Table10. Setting the system MTU | Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| System MTU | C4500-X(config)#system mtu ?
<1500-1552> MTU size in bytes
C4500-X(config)#int te 1/3
C4500-X(config-if)#mtu ?
<1500-9198> MTU size in bytes | C9500-40X(config)#system mtu ?
<1500-9198> MTU size in bytes
(This is a global command.) |
IP routing The IP routing command is required on the Cisco Catalyst 9500 Series for Layer 3 routing:
C9500-40X
#conf t
Enter configuration commands, one per line. End with CNTL/Z.
C9500-40X(config)
#ip routing
C9500-40X(config)
#endC9500-40X
#wrStackWise Virtual The Cisco Catalyst 4500-X Series supports VSS, which combines a pair of switches into a single network element. Similarly, the Cisco Catalyst 9500 Series supports StackWise Virtual, which can provide the same functionality as VSS by extending proven back-panel technology over front-panel network ports (Figure 2).
Figure2. StackWise Virtual
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Cisco StackWise Virtual is a network system virtualization technology that pairs two Cisco Catalyst 9000 family switches into one virtual switch. Cisco Catalyst 9000 family switches in a Cisco StackWise Virtual solution simplify operational efficiency with a single control and management plane, scale system bandwidth with a distributed forwarding plane, and assist in building resilient networks using the recommended network design. Cisco StackWise Virtual allows two physical Cisco Catalyst 9500 Series Switches to operate as a single logical virtual switch using a 40 Gigabit or 10 Gigabit Ethernet connection.
Use the steps below to configure StackWise Virtual.Step1: StackWise Virtual domain| SW-1 | SW-2 |
9500-Dist-1(config)# stackwise-virtual
9500-Dist-1(config)# domain <1-255> | 9500-Dist-2(config)# stackwise-virtual
9500-Dist-2(config)# domain <1-255> |
Step2: StackWise Virtual link| SW-1 | SW-2 |
9500-Dist-1(config)# interface range FortyG x/y/z
9500-Dist-1(config-if)# stackwise-virtual link <1 | 255> | 9500-Dist-2(config)# interface range FortyG x/y/z
9500-Dist-2(config-if)# stackwise-virtual link <1 | 255> |
Step3: Dual-active detection| SW-1 | SW-2 |
9500-Dist-1(config)# interface range TenG x/y/z
9500-Dist-1(config-if)# stackwise-virtual dual-active-detection | 9500-Dist-2(config)# interface range TenG x/y/z
9500-Dist-2(config-if)# stackwise-virtual dual-active-detection |
Step4: Save and reload to convert| SW-1 | SW-2 |
9500-Dist-1# copy run start
9500-Dist-1# reload | 9500-Dist-2# copy run start
9500-Dist-2# reload |
For more information, refer to the StackWise Virtual configuration guide for the Cisco Catalyst 9500 Series:
https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst9500/software/release/16-6/ configuration_guide/b_166_ha_9500/b_166_ha_9500_chapter_01.htmlHost tracking feature The Cisco Catalyst 4500-X Series supports IP device tracking (IPDT) for keeping track of connected hosts (association of MAC and IP addresses). In the Cisco Catalyst 9500 Series with the latest Cisco IOS XE release, the new switch integrated security features (SISF)-based IP device-tracking feature acts as a container policy that enables the snooping and device-tracking features available with First Hop Security (FHS) in both IPv4 and IPv6, using IP-agnostic CLI commands. The command “device-tracking upgrade-cli” allows you to migrate the existing IPDT configuration to the new SISF-based device-tracking CLI commands.
Please see Appendix A for detailed information on migrating from the IPDT CLI configuration to the new SISF-based device-tracking CLI configuration.
Flexible NetFlow Both the Cisco Catalyst 9500 Series and the Cisco Catalyst 4500-X Series support Flexible NetFlow. Beside the scalability differences, there are a few configuration differences. They are listed in Table 11.
Table11. Flexible NetFlow differences
| Cisco Catalyst 4500-X Series | Cisco Catalyst 9500 Series |
| Timestamp | Use system uptime | Use absolute time [0 is at time 00:00:00 January 1, 1970] |
| NetFlow on port-channel | Configuration under port-channel | Configuration under member of port-channel |
| Bridged traffic | Apply the flow monitor to the Layer 2 interface with keyword “layer2-switched” | Apply the flow monitor to a VLAN |
Quality of service (QoS) The ASICs that power the Cisco Catalyst 4500-X and 9500 Series are different, so there are some difference in QoS behaviors, as described below.
Per-port per-VLAN QoS policy The Cisco Catalyst 4500-X Series provides the ability to configure service policy per VLAN under the trunk interface. The Cisco Catalyst 9500 Series supports this with the use of Hierarchical QoS. In this case, the parent policy consists of two different VLAN policies. Table 12 gives an example.
Table12. Per-port per-VLAN configuration
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Congestion avoidance The Cisco Catalyst 4500-X Series supports Dynamic Buffer Limiting (DBL) as a hardware feature, and there are no user-configurable parameters. The Cisco Catalyst 9500 Series uses Weighted Random Early Detection (WRED), which randomly discards packets at specified queue thresholds. WRED gives the network operator much more control over the drop behavior. The following is an example of WRED configuration on the 9500 Series.
policy-map 2P6Q3T class PRIORITY-QUEUE priority level 1 class VIDEO-PRIORITY-QUEUE priority level 2 class DATA-QUEUE bandwidth remaining percent <number> queue-buffers ratio <number> random-detect dscp-based random-detect dscp 10 percent 60 80Table13 lists other QoS differences between the Cisco Catalyst 4500-X and 9500 Series.
Table13. QoS differences
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Cisco Catalyst 4500-X Series platform-specific commands Table14 lists commands that are specific to the Cisco Catalyst 4500-X Series and are not available on the 9500 Series.
Table14. Cisco Catalyst 4500-X Series platform-specific commands
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Conclusion The Cisco Catalyst 9500 Series is the industry’s first purpose-built 40-Gbps fixed-core/aggregation enterprise switching platform. It is the new generation of fixed-core/aggregation platforms and provides many additional capabilities. It is well suited for enterprises looking to migrate from their existing Cisco Catalyst 4500-X Series deployment.
Appendix A. IPDT/SISF If your device has no legacy IP device tracking or IPv6 snooping configurations, you can use only the new SISF-based device-tracking commands for all your future configurations. The legacy IPDT commands and IPv6 snooping commands are not available.
IPDT, IPv6 snooping, and device-tracking CLI compatibility
Table 15 displays the new SISF-based device-tracking commands and the corresponding IPDT and IPv6 snooping commands.
Table15. Device-tracking and corresponding IPDT and IPv6 snooping commands
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Info from
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