Release Notes for Cisco ESR6300 Router, IOS XE 26.2.x
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Cisco ESR6300 Routers, IOS XE 26.2.x
Cisco ESR6300 Routers, IOS XE 26.2.x
This release note provides information about the new features, resolved and open issues, supported software packages and information on how to obtain support and documentation.
This section provides a brief description of the new software features introduced in this release.
IOS XE 26.2.1
Table 1. New software features for Cisco ESR6300 Routers, IOS XE 26.2.1
| Product Impact |
Feature |
Description |
| Security |
As part of Cisco’s Resilient Infrastructure program and Cisco’s commitment to secure infrastructure, this release includes additional changes aimed towards continuing to make Cisco IOS XE more secure by default. Note that some of these changes may require operational changes if you are not following secure best practices. This release includes the following changes: · The RADIUS client appends the Message-Authenticator attribute (Attribute 80 HMAC-MD5) to all outgoing Access-Request packets to mitigate cryptographic forgery and Blast-RADIUS vulnerabilities (CVE-2024-3596). · The RADIUS client drops incoming Access-Accept, Access-Reject, and Access-Challenge packets if the Message-Authenticator is absent or invalid. Ensure AAA servers (example, Cisco ISE) are configured to return Attribute 80. · Outbound SSH connections enforce Trust-On-First-Use (TOFU). The device prompts to verify and store remote server host keys in the known-hosts database on first connection and validates against them on subsequent sessions. · Proxy ARP is disabled by default across all routed interfaces, SVIs, and sub interfaces to reduce Layer 2 broadcast domains and prevent ARP spoofing. Configure the ip proxy-arp command explicitly if required. · The embedded web server daemon is disabled by default on factory configurations to restrict unauthenticated management access. Web UI and RESTCONF require explicit enablement of the ip http secure-server command. · The IOS XE device rejects unauthenticated NTP Mode 6 and Mode 7 control queries (monlist) to prevent NTP reflection and amplification DDoS attacks. Standard time synchronization (Modes 3 and 4) is unaffected. · System logging timestamps automatically include the four-digit calendar year (service timestamps log datetime msec year) to standardize multi-year audit logs and SIEM compliance. · Integrates Linux auditd inside Cisco IOx Guest Shell. All commands, system calls, and privilege escalation events (sudo) executed inside the container are forwarded to the host syslog facility. · Warning messages are emitted on the console and logged to syslog whenever legacy insecure protocols (telnet, ftp, tftp, http) are enabled in the configuration. Real-time tracking of active insecure services is published to the operational database (operDB) and YANG data models, allowing management controllers (such as Cisco Catalyst Center) to monitor security compliance. |
|
| Greater Control |
DHCP Option 82 |
From this release, DHCP servers on routers support DHCP Option 82 relay information. The DHCP server can use the Circuit ID and Remote ID inserted by a DHCP relay agent to select an address pool for a client. This support enables predictable, location-based IP address assignment without requiring administrators to track client MAC addresses. Supported devices: ESR6300 |
| Enhanced Security |
IKEv2 and IPsec PFS Post Quantum Cryptography
|
This feature combines a traditional Diffie-Hellman key exchange with the NIST-standardized Module-Lattice-Based Key-Encapsulation Mechanism (ML-KEM) to establish keys for IKEv2/IPsec sessions. This hybrid approach helps protect recorded VPN traffic against future harvest-now, decrypt-later attacks. You can configure ML-KEM algorithms with IPsec Perfect Forward Secrecy. Supported devices: ESR6300 |
| Enhanced Security |
Post Quantum Cryptography for SSHv2 Sessions |
Starting with this release, you can configure ML-KEM-based hybrid key-exchange algorithms for SSHv2 client and server sessions. These algorithms combine ML-KEM with a classical elliptic-curve component to provide quantum-resistant key establishment for secure remote management. PQC algorithms must be explicitly enabled and are not supported when the device operates in FIPS mode. |
| Greater Control |
Segment Routing over MPLS on WAN Ports |
From this release, you can configure Segment Routing over Multiprotocol Label Switching (SR-MPLS) on supported WAN ports. SR-MPLS encodes an ordered list of segments in the packet and integrates with MPLS services such as Layer 3 VPN and Ethernet VPN. It provides scalable path control, traffic-engineering capabilities, and protection against link and node failures without requiring per-flow state in the network. Supported devices: ESR6300 |
IOS XE 26.2.1
There are no new hardware features in this release.
IOS XE 26.2.1
There is no change in behavior in this release.
Note: This software release may contain bug fixes first introduced in other releases. To see additional information, click the bug ID to access the Cisco Bug Search Tool.
Table 2. Resolved issues for Cisco ESR6300 Router, IOS XE 26.2.1
| Bug ID |
Description |
| NVRAM Header Corruption on Power Cycle on IR8100, IR1101 and C6300 devices |
IOS XE 26.2.1
There are no open issues in this release.
IOS XE 26.2.1
There are no known issues in this release.
This section provides compatibility details for cellular module modem firmware and OEM/PRI versions used in Cisco IoT routers. It includes the latest modem firmware available for each supported modem. See the Cisco Firmware Upgrade Guide for 4G LTE and 5G Cellular Modems for upgrade instructions.
Cisco IOS XE updates do not automatically update modem firmware. You must manually check and update all modems to the latest firmware version, including any related PRI or OEMPRI components. Refer to the following table for the most up-to-date information.
Table 3. Cellular Module Modem Firmware for Cisco ESR6300 Router, IOS XE 26.2.x
| Cellular Module |
Modem |
Software download link |
| P-LTE-MNA |
WP7610 02.37.03.05 |
|
| P-LTE-LA |
EM7430 2.38.00.00 |
Generic: |
|
|
EM7430 02.33.03.00 |
Australia Telstra: |
|
|
EM7430 2.38.00.00 |
Japan: |
| P-LTEA-EA |
EM7455 02.39.00.00 |
Generic: |
|
|
EM7455 02.39.00.00 |
Europe: |
|
|
EM7455 02.32.11.00 |
Canada: |
|
|
EM7455 02.32.11.00 |
North America ATT: |
|
|
EM7455 02.32.11.00 |
North American Sprint: |
|
|
EM7455 02.33.03.00 |
North America Verizon: |
| P-LTEAP18-GL |
LM960 32.00.1x9 |
Generic: |
|
|
LM960 32.00.1x9 |
North America: |
| P-5GS6-GL |
FN980 38.03.0202 |
|
| P-5GS6-R16SA-GL |
EM9293 03.04.10.01 |
https://software.cisco.com/download/home/286334597/type
|
This section provides information about the release packages associated with Cisco ESR6300 Router.
For the latest software downloads, see the Software Download page.
IOS XE 26.2.1
Table 4. Software packages for Router, IOS XE 26.2.1
| Image type |
Filename |
| Universal |
c6300-universalk9.26.02.01.SPA.bin |
This section shows the names of the ports on Cisco ESR6300 Series Router.
Table 5. Naming Conventions on Cisco ESR6300 Series Router
| Port |
Naming Convention |
| Gigabit Ethernet combo port WAN Layer3 |
GigabitEthernet0/0/0 GigabitEthernet0/0/1 |
| Gigabit Ethernet LAN Layer 2 ports |
GigabitEthernet0/1/0 GigabitEthernet0/1/1 GigabitEthernet0/1/2 GigabitEthernet0/1/3 |
| Cellular Interface |
Cellular0/3/0 Cellular0/3/1 |
| USB Port |
usbflash0: (IOS and ROMMON) |
Related resources
Table 6. Related resources
| Document |
Description |
| Provides information about products supported by Cisco IOS XE. |
|
| Provides information about Cisco ESR6300 Embedded Series Router. |
|
| Cisco Industrial Routers and Industrial Wireless Access Points Antenna Guide |
Provides information about Cisco Industrial Routers and Industrial Wireless Access Points. |
| Provides information about Cisco IOS XE 26 software. |
|
| Provides information about Cisco SD-WAN routers. |
|
| Provides information about Cisco IoT Field Network Director. |
|
| Provides information about Cisco Industrial Network Director. |
|
| Provides information about Smart Licensing Using Policy solutions and their deployment on IOS XE routers. |
|
| You can submit a service request here. |
|
| Provides the most up-to-date detailed troubleshooting information. |
|
| Use CFN to browse Cisco products and find relevant features and licenses. It allows you to compare platforms, determine common features between products, and identify unique product features. The CFN also has a tab that provides a MIB Locator. |
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