C2691-advipservicesk9-mz.124-17.image May 2026

C2691-advipservicesk9-mz.124-17.image is a specific Cisco IOS software image designed for the Cisco 2691 series router . It runs the Advanced IP Services feature set on the

mainline release. This image is widely recognized in the networking community as a "gold standard" for lab environments and certification prep due to its stability and broad feature support. Image Specification Breakdown Platform (C2691):

Specifically for the Cisco 2691 modular router, a high-performance member of the 2600 family. Feature Set (advipservicesk9): Represents Advanced IP Services

. The "k9" indicates support for strong 128-bit/256-bit payload encryption (3DES/AES). Execution Location (mz): The image runs from RAM ("m") and is compressed ("z"). Version (12.4-17):

A stable release from the Cisco 12.4 mainline, known for reliability in production and lab scenarios. Key Capabilities C2691-advipservicesk9-mz.124-17.image

This feature set is robust, bridging the gap between standard IP Base and full Advanced Enterprise images. Configuring complex dynamic ACL (Lock-and-Key) | NIL

The string "C2691-advipservicesk9-mz.124-17.image" refers to a specific Cisco IOS (Internetworking Operating System) software image.

Here is a detailed breakdown of the "deep features" (naming conventions and capabilities) encoded in this filename:

Multiprotocol Label Switching (MPLS)

• AT&T, Verizon, and other carriers often required CPE routers to support MPLS. This image allows the 2691 to act as a PE (Provider Edge) or CE (Customer Edge) router running LDP, MP-BGP, and MPLS VPNs (VRF).

9. Comparison to Similar Images

| Image Name | Platform | Feature Set | Main Difference | | :--- | :--- | :--- | :--- | | C2691-advipservicesk9-mz.124-17.image | 2691 | Advanced IP Services + VPN + MPLS | Full enterprise routing | | C2691-ipbase-mz.124-17.image | 2691 | IP Base only | No VPN, no MPLS, no advanced QoS | | C2691-advsecurityk9-mz.124-17.image | 2691 | Advanced Security | VPN + Firewall, but no MPLS / IPv6 | | c3725-adventerprisek9-mz.124-15.T14.image | 3725 | Enterprise Plus | Similar but for 3725 platform; newer IOS 12.4(15)T | C2691-advipservicesk9-mz

Understanding the Cisco C2691-advipservicesk9-mz.124-17.image: A Deep Dive into Legacy IOS

8. Important Security Note

Do not use this image on a production network connected to the internet. It has unpatched vulnerabilities:

• CVE-2018-0151 (Cisco IOS IKE remote code execution)
• CVE-2018-0171 (Smart Install – not present on 2691 but similar SNMP vulns)
• Many known DoS and RCE flaws from 2005–2015 era.

Use only in isolated labs.

5. License & Crypto Activation

Since it has k9:

• You need the 3DES/AES software license (even for lab use on old gear, legally you need entitlement, but for home labs Cisco no longer enforces).
• The router will run IPSec without extra license key on most 12.4(17) builds, but you may see:

  %CRYPTO-6-ISAKMP_ON_OFF: ISAKMP is ON
  

  If crypto commands are rejected, check:

  show license feature
  

If you see License Level: advipservices and K9: yes, you're fine. AT&T, Verizon, and other carriers often required CPE

10. Where can you legally obtain it?

• Legally: If you own a C2691 with the original entitlement, from Cisco.com (requires active SmartNet contract – impossible now for EOL gear).
• Practically: It exists in old lab archives and GNS3 appliance repos. Cisco no longer distributes it publicly.

1. File Name Breakdown

Understanding the filename tells you everything about the file's purpose.

| Part | Meaning | | :--- | :--- | | c2691 | Platform: Cisco 2691 router | | advipservicesk9 | Feature Set: Advanced IP Services with K9 = Encryption (3DES/AES) | | mz | Image type: main image, zipped (compressed) | | 124-17 | IOS version: 12.4(17) | | .image | File extension (Cisco IOS image) |

Note: Older Cisco IOS files often used .bin extension. .image is functionally identical.

4. Use Cases: Where Would You Still Encounter This Image in 2025?

While the Cisco 2691 was declared End-of-Life (EoL) by Cisco years ago, you will still encounter C2691-advipservicesk9-mz.124-17.image in specific environments: