Cisco brings in its new software release IOS-XE 17.16.1, which offers a suite of new software features and enhancements to existing features for our Catalyst 9K portfolio. This update ensures a seamless networking experience within the Catalyst 9000 switching ecosystem.This is a Standard Maintenance Release and has a support lifetime of 12 months.
Below is a high-level list of features/enhancements that were added across areas of Catalyst C9K Switching Platform/Infra, Security, Sustainability & Programmability.
As businesses increasingly rely on multicast applications for video conferencing etc, ensuring stable and efficient multicast routing has never been more important. Cisco’s latest enhancement, the Multicast Flow-Aware SG-timer, addresses a key challenge in multicast connectivity—premature deletion of multicast routes.
With the new SG-timer feature in IOS-XE 17.16.1, when a new multicast route is created, it’s automatically marked as ‘active.’ Even if traffic stops for less than two minutes, the route will be kept alive for another cycle, reducing the chances of premature deletion. Hence, if traffic stops on a newly created (S,G) mroute within the first 2-minute cycle (e.g., at 50 seconds), the mroute age shall be extended for another 2-minute cycle. And then, if the mroute remains unused during this extended period (no traffic flow), the (S,G) mroute is then deleted. This feature significantly improves Layer 2 multicast connectivity by ensuring more reliable traffic flow, even during short bursts of inactivity.
Another enhancement on the routing side is for NAT feature which now supports ECMP (Equal-Cost Multi-Path) topologies, allowing both static and dynamic NAT rules across multiple equal-cost paths. ECMP can be configured independently on NAT inside or outside interfaces. However, all paths must be NAT-enabled for predictable behavior, ensuring reliable traffic flow in complex networks.
Network stability and reliability are crucial for maintaining uninterrupted service, and one of the biggest threats to this is the potential for network loops. STP Bridge Assurance support—addresses this issue by preventing loops caused by unidirectional links or malfunctioning devices (like "brain dead" switches that stop sending BPDUs but continue forwarding traffic). With Bridge Assurance, the system continuously monitors BPDUs, automatically blocking ports that stop receiving them, and only resuming normal operations once BPDUs are detected again. This simple but powerful mechanism prevents broadcast storms and helps maintain a stable network environment. With IOS-XE 17.16, Bridge Assurance support is now extended to the Cisco Catalyst 9300 and 9400 Series Switches.
In today’s fast-paced networking environments, high availability is critical to ensuring seamless operations and minimizing downtime. Cisco’s latest software enhancements in IOS-XE 17.16.1, include two new enhancements which are designed to improve upon the unprecedented reliability of the C9000 switches.
The Quad-Supervisor with Route Processor Redundancy (RPR) feature now allows dual supervisors to be leveraged on both chassis when configured with StackWise Virtual. This additional redundancy ensures faster recovery and operational readiness in the event of a supervisor failure or a forced switchover. This feature provides:
- Faster recovery and minimal disruption during supervisor failures.
- Seamless failover to maintain full operational bandwidth.
While this feature is already supported on Catalyst 9600 with Supervisor 1, with IOS-XE 17.16.1 release, we are adding support for C9600X-SUP-2.
Starting with IOS-XE 17.15.2, the xFSU (Extended Fast Software Upgrade) on the Catalyst 9300 platform now reduces traffic downtime during reloads and upgrades from < 30 secs to < 5 secs. This significant enhancement enables faster, seamless reloads/upgrades while continuing to support both Layer 2 and Layer 3 networks in standalone and stack configurations without any topology modifications, while also, ensuring hitless Perpetual PoE for uninterrupted power to connected devices.
In an era of rapid digital transformation, network security is more important than ever, and customers continue to leverage the power of Trustec to segment their network with no impact to network design whilst protecting critical business assets. We have added some key enhancements with this release. Prior to IOS-XE 17.16, customers could assign statically only one SGT tag to a client on an interface. However, customers have use cases where they will be putting multiple devices behind phones. With this Multiple Static SGTs on interface feature introduced on IOS-XE 17.16, it allows for two SGTs tags in different Vlans, to be assigned statically per interface, to allow for multi device SGT assignment on an interface.
The sustainability innovations within this release achieve an impressive 10% power savings on C9300 stacked switches. With a simple auto-off command applied to LEDs, SFPs and Power supplies, we can now reduce the system power footprint and help customers save energy. A perfect just in time for the year end shutdowns and power savings
- Auto-off C9300 StackPower PSUs
- Every power supply off lined shows an average of 8-10 watt power savings and an improvement of 15 to 20% operational efficiency.
- Auto-off SFP port on C9200, C9300
- Auto-disables SerDes when there is no SFP module is present on the port-group.
- Auto-off switchport LED C9200, C9300
- Auto-depower port LEDs to conserve energy and turn specific port LED on/off in the event of a mode button-press on the front panel of the switch or a Link event such as port going up/down occurs.
To continue to improve on the need for agility and efficiency in network management, we have introduced some enhancements with IOS-XE 17.16 when it comes to Day 0 Provisioning along with Programmability & Automation.
In previous releases, ZTP on the C9200CX was limited to the LAN. This IOS release brings external network connectivity to the ZTP Guest Shell to now provide Zero Touch Provisioning (ZTP) support on C9200CX.
The Guest Shell (during ZTP only) can now access any external resources and is not limited to the LAN. A different network with a different subnet can be reached to retrieve the ZTP file, or we can even go out to the internet to retrieve the ZTP file from a different source.
With every Cisco IOS-XE release, we have additional YANG model support. In the 17.16 release, we have two new Native YANG models, four new Events models, two additional RPC models and nine new common models. The seventeen new models for this release show Cisco’s continued support for programmability and automation efforts.
To better understand and leverage YANG models, we have recently published a new YANG Suite hands-on learning lab. In the lab, you can access YANG Suite as well as walk through various modules to understand how to leverage YANG models with NETCONF, RESTCONF, gNMI, gRPC, SNMP to YANG xPath mapping and much more! Check out the Learning Lab today at: https://devnetapps.cisco.com/learning/labs/intro-yangsuite/introduction-launching-yang-suite/
The IOSXE Terraform Provider is a tool to help with programmability and automation efforts using RESTCONF. This provider declaratively manages 19 features using 98 resources & data sources. Additionally, there are two imperative resources for configuration support using CLI and YANG.
Finally, with IOS-XE 17.16, we have enabled and extended optic support to our 9000-X series platforms, to continue to drive adoption. We now support the following optics on these platforms
- QSFP-100G-FR-S on C9400X-SUP-2XL and all 100G capable line cards
- QDD-400G-LR4-S on C9600-LC-40YL4CD and C9600X-LC-32CD
Summary
IOS-XE 17.16.1 brings key features in Platform, Security, Sustainability & Programmability.
Find platform specific release notes for IOS-XE 17.16.1 below:
What’s Next?
IOS-XE 17.17.1 will be a standard maintenance release and is targeted for release in April of 2025. Stay tuned for more information on new software releases!
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