Release Notes for Cisco IOS XRv 9000 Routers, IOS XR Release 26.3.1
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Cisco XRv 9000 Routers, IOS XR Release 26.3.1
Cisco XRv 9000 Routers, IOS XR Release 26.3.1
Cisco IOS XR Release 26.3.1 for Cisco XRv 9000 Routers advances software reliability and operational security through targeted innovations in routing and system protection. This release strengthens routing architecture with BGP full path reflection, empowering route reflectors to advertise multiple unique BGP paths per prefix and thereby enhancing network visibility and traffic engineering capabilities. In the realm of security, it introduces gated shell access, which enforces cryptographic Consent Token authorization for direct root shell access, ensuring secure, auditable, and persistent control over privileged operations. Additionally, SSH client strict host key check is implemented to bolster outbound SSH connection security by enforcing rigorous host key validation policies and maintaining trusted key persistence across reloads. Collectively, these features reinforce the platform’s reliability, security posture, and operational integrity for service provider and enterprise deployments.
For more details on the Cisco IOS XR release model and associated support, see Software Lifecycle Support Statement - IOS XR.
This section provides a brief description of the new software features introduced in this release.
Table 1. New software features for Cisco XRv 9000 Routers, Release 26.3.1
| Product impact |
Feature |
Description |
| BGP |
||
| Software reliability
|
You gain full visibility into all eligible BGP paths per prefix as route reflectors can now advertise multiple unique paths, not just one per next hop. This enables more informed routing and traffic engineering, with exact duplicate paths still suppressed. |
|
Deprecation and phasing out features with insecure capabilities and its secure alternatives
In Release 26.3.1, Cisco IOS XR software displays warning messages when you configure features or protocols that lack sufficient security, such as those that transmit sensitive data without encryption or use outdated encryption mechanisms. The software also shows warnings when you do not follow security best practices, and it provides suggestions for secure alternatives.
This list may change, but Cisco plans to generate warnings for the following features and protocols from Release 25.3.1. Each Release Notes will describe the exact changes for that version.
These documents list all features planned for removal, including insecure commands, and provide recommended secure alternatives to help you maintain network security and compliance.
o Feature deprecation phasing out insecure capabilities
o Feature deprecation and removal details
o Feature removal and suggested alternatives
Table 2. Deprecation and phasing out features with insecure capabilities and its secure alternatives
| If you are using the following insecure features… |
Then follow these secure alternatives… |
| TLS 1.0 |
Use TLS 1.2 or TLS 1.3. |
| SSH key-exchange algorithm diffie-hellman-group1-sha1 |
Use stronger SSH key-exchange algorithms. Do not configure diffie-hellman-group1-sha1. |
| SSH ciphers 3des-cbc |
Use stronger SSH ciphers. |
| SSH host-key DSA algorithm |
Use ECDSA, ED25519, or RSA host keys. Note: The SSH host-key DSA algorithm is not recommended. However, it has not been removed. If required, you can still generate and use DSA host keys. Cisco recommends using ECDSA, ED25519, or RSA host keys. |
| SSHv1 |
Use SSHv2. |
There are no open issues in this release.
There are no known issues in this release.
Appliance model
Cisco IOS XRv 9000 Appliance is the pre-installed Cisco IOS XRv 9000 Router software that is sent from the factory on a bare metal UCS server hardware. It supports hyper scalability as it can scale to 70 million route prefixes when run as a Virtual Route Reflector. Therefore, the extra layer of software (hypervisor) is not required.
The Appliance also supports Zero Touch Provisioning (ZTP) which allows easier insertion into existing networks.
Table 3. Specification of the Cisco XRv 9000 Appliance
| Parameters |
Supported |
| Form Factor |
1 RU |
| Processor |
5th Gen Intel Xeon Scalable processor Intel(R) Xeon(R) Gold 5520+ 2.2GHz/205W 28C/52.5MB DDR5 4800MT/s |
| 4th Gen Intel Xeon Scalable processor Intel I5420+ 2GHz/205W 28C/52.5MB DDR5 4400MT/s |
|
| Memory size |
128GB (8x16GB DDR5-4800 RDIMM 1Rx8) |
| Internal storage |
480GB M.2 Boot SATA Intel SSD |
| Software version |
Cisco IOS-XR version 24.4.2 and later |
| Firmware version |
BIOS version: C220M7.6.0.1a.0_XRV9K CIMC/BMC version: 6.0(1.250129) |
| Physical NICs |
25G Model: Cisco-Intel E810XXVDA4L 4x25/10 GbE SFP28 PCIe 100G Model: Cisco-MLNX MCX623106AS-CDAT 2x100GbE QSFP56 PCIe Cisco-MLNX MCX623106AS-CDAT 2x100GbE QSFP56 PCIe |
Hypervisors
A hypervisor enables multiple operating systems to share a single hardware host machine. While each operating system appears to have the dedicated use of the host's processor, memory, and other resources; the hypervisor controls and allocates only needed resources to each operating system and ensures that the operating systems (VMs) do not disrupt each other.
Installation of the Cisco IOS XRv 9000 Router is supported on selected Type 1 (native, bare metal) hypervisors. Installation is not supported on Type 2 (hosted) hypervisors, such as VMware Fusion, VMware Player, or Virtual Box. The following table lists release specific supported hypervisor versions.
Table 4. Support Matrix for Hypervisor Versions
| Cisco IOS XR Version |
VMWare ESXi |
Kernel Based Virtual Machine (KVM) |
| Release 26.3.1 |
Version 8.0 |
Linux KVM based on Red Hat Enterprise Linux 8.10 and 9.6 |
Virtual machines
Cisco IOS XRv 9000 Router virtual machines must meet the following requirements:
Table 5. VM Requirement for VMware Environment
| Parameters |
Supported |
| VMware ESXi |
Version 8.0 |
| Virtual CPU cores |
1 socket with a minimum of 4 cores Note: For multicast heavy deployments we recommend configuring 8 cores (with 4 assigned for control plane and 4 assigned for data plane). Note: For production environment minimum of 4 cores is recommended. |
| Virtual Machine memory size |
The supported memory size is 64 GB for the default image and a minimum of 115 GB for VRR scenarios. |
| Virtual Machine hard disk size |
128 GB minimum disk size for vPE and vRR image variants |
| Virtual Interfaces |
● E1000
● VMXNET3 for traffic interfaces only
|
| Physical NICs |
For pass-through:
● Intel X710, XXV710
● Mellanox ConnectX 6
SR-IOV supported for:
● Intel E810 XXV, E810 C
● Intel X710, XXV710
|
| Number of interfaces |
Maximum of 11 NICs where:
● 1 for management
● 2 are reserved
● 8 for traffic
|
| Default video, SCSI controller set |
Required SCSI controller not required for IDE disk. |
| Virtual CD/DVD drive installed |
Virtual CD/DVD is required when installing the Cisco IOS XRv 9000 Router on the VM using ISO template. |
| IDE hard disk |
Single IDE hard disk Note: Multiple hard disk drives on a VM are not supported. |
Firmware update available for UCS M7 appliance (xrv9k-ucs-c220m7-huu-container-6.0.1.250127.tar.gz)
A firmware update package, xrv9k-ucs-c220m7-huu-container-6.0.1.250127.tar.gz, is now available for the UCS M7 appliance. This package includes firmware for both the CIMC and BIOS.
The SHA256SUM checksum for the package is: 5a7b409b58003f3b298227b6d3cc83325f0b3b0b4ef2181553209f4df942048e
The SHA256SUM checksum for the CIMC and BIOS binaries are:
● bios.pkg 5567aea1a085dd1e8300be692639fbad01f792d6aed39a5a7bad1e162673a031
● cimc.bin b5bace7d6126de3196057b08aa54391c2a178d3e7532ce62ef1c6803dfd75aec
For detailed instructions on extracting and installing the firmware, please refer to the documentation at Firmware Files.
Optics support
Table 6. Optics support for the XRv 9000 Routers
| Product |
Product Code |
Product Recommendation |
| Cisco 100GBASE LR4 QSFP Transceiver, LC, 10km over SMF |
Cisco QSFP-100G-LR4-S |
XRv9000 Appliance with UCS-C220 M7 server, 2X100G |
| Cisco 100GBASE SR4 QSFP Transceiver, MPO, 100m over OM4 MMF |
Cisco QSFP-100G-SR4-S |
|
| Cisco 10GBASE SFP+, Short Range |
Cisco SFP-10G-SR |
XRv9000 Appliance with UCS-C220 M7 server - 4X10/25G |
| Cisco 10GBASE SFP+, Long Range |
Cisco SFP-10G-LR |
Table 7. Related resources
| Resource |
Description |
| Provides access to Cisco product documentation for checking feature support details. |
|
| Allows searching by release number, error strings, or comparing release numbers to view a detailed repository of error messages and descriptions. |
|
| Allows selecting the MIB of your choice from a drop-down to explore an extensive repository of MIB information. |
|
| Provides CDC documentation for Cisco XRv 9000 routers. |
|
| Outlines the features currently supported by each operating system.
|
|
| Provides a list of insecure features and protocols that are scheduled for systematic deprecation and eventual removal from specified Cisco products.
|
|
| Details the reasons why certain features or protocols are deemed insecure and offers secure alternatives when available. |
|
| Provides a general guide in case of upgrading IOS XR routers or new deployments that involve IOS XR routers. |
|
| Provides information about Smart Licensing Using Policy solutions and their deployment on IOS XR routers. |
|
| Allows searching by product family, product ID, data rate, reach, cable type, or form factor to determine the transceivers that Cisco hardware device supports. |
|
| Provides yang data models introduced and enhanced in every IOS XR release. |
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