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Cisco IOS and NX-OS Software
Cisco IOS 15.1SY
Status
Available
Series Release Date
15-OCT-2012
This product is supported by Cisco, but is no longer sold.
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Recent Security Notices
06-Nov-2025
Security Advisory: Cisco Secure Firewall Adaptive Security Appliance Software, Secure Firewall Threat Defense Software, IOS Software, IOS XE Software, and IOS XR Software Web Services Remote Code Execution Vulnerability
24-Sep-2025
Security Advisory: Cisco IOS and IOS XE Software CLI Denial of Service Vulnerability
20-Aug-2025
Security Advisory: Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability
14-Aug-2025
Security Advisory: Cisco IOS, IOS XE, Secure Firewall Adaptive Security Appliance, and Secure Firewall Threat Defense Software IKEv2 Denial of Service Vulnerabilities
30-Jul-2025
Security Advisory: SNMP Remote Code Execution Vulnerabilities in Cisco IOS and IOS XE Software
Document Categories
Configuration
Data Sheets and Product Information
Reference
Security Notices
Data Sheets and Product Information
End-of-Life and End-of-Sale Notices
End-of-Sale and End-of-Life Announcement for the Cisco IOS Software Release 15.1(2)SY for the Cisco Catalyst 6500 Series Switches
09-Feb-2016
Security Notices
Security Advisories, Responses and Notices
Cisco Secure Firewall Adaptive Security Appliance Software, Secure Firewall Threat Defense Software, IOS Software, IOS XE Software, and IOS XR Software Web Services Remote Code Execution Vulnerability
06-Nov-2025
Cisco IOS and IOS XE Software CLI Denial of Service Vulnerability
24-Sep-2025
Cisco IOS and IOS XE Software Smart Install Remote Code Execution Vulnerability
20-Aug-2025
Cisco IOS, IOS XE, Secure Firewall Adaptive Security Appliance, and Secure Firewall Threat Defense Software IKEv2 Denial of Service Vulnerabilities
14-Aug-2025
SNMP Remote Code Execution Vulnerabilities in Cisco IOS and IOS XE Software
30-Jul-2025
Cisco IOS, IOS XE, and IOS XR Software TWAMP Denial of Service Vulnerability
07-May-2025
Cisco IOS and IOS XE Software SNMPv3 Configuration Restriction Vulnerability
07-May-2025
Cisco Adaptive Security Appliance Software, Firepower Threat Defense Software, IOS Software, and IOS XE Software IKEv2 Denial of Service Vulnerability
07-May-2025
Cisco IOS, IOS XE, and IOS XR Software SNMP Denial of Service Vulnerabilities
12-Mar-2025
Cisco IOS and IOS XE Software Resource Reservation Protocol Denial of Service Vulnerability
25-Sep-2024
Cisco IOS and IOS XE Software Intermediate System-to-Intermediate System Denial of Service Vulnerability
27-Mar-2024
Cisco IOS and IOS XE Software Locator ID Separation Protocol Denial of Service Vulnerability
27-Mar-2024
Cisco IOS and IOS XE Software Internet Key Exchange Version 1 Fragmentation Denial of Service Vulnerabilities
27-Mar-2024
Cisco IOS and IOS XE Software Command Authorization Bypass Vulnerability
13-Oct-2023
Cisco IOS and IOS XE Software Cisco Group Encrypted Transport VPN Software Out-of-Bounds Write Vulnerability
27-Sep-2023
Reference
Command References
Cisco IOS Security Command Reference: Commands S to Z
28-Aug-2024
Cisco IOS IP Routing: ISIS Command Reference
30-Apr-2024
Cisco IOS IP Routing: OSPF Command Reference
30-Apr-2024
Cisco IOS Interface and Hardware Component Command Reference
05-Oct-2023
Cisco IOS Security Command Reference: Commands A to C
11-Jan-2021
Cisco IOS Embedded Event Manager Command Reference
16-Sep-2020
Cisco IOS IP Switching Command Reference
17-Aug-2020
Cisco IOS First Hop Redundancy Protocols Command Reference
21-Jun-2020
Cisco IOS Scripting with TCL Command Reference
11-Jun-2020
Cisco IOS Multiprotocol Label Switching Command Reference
10-Jun-2020
Cisco IOS Service Advertisement Framework Command Reference
09-Jun-2020
Cisco IOS HTTP Services Command Reference
09-Jun-2020
Cisco IOS IP Application Services Command Reference
26-Apr-2020
Cisco IOS High Availability Command Reference
06-Mar-2020
Cisco IOS Security Command Reference: Commands D to L
17-Dec-2019
View all documentation of this type
Configuration
Configuration Examples and TechNotes
Simultaneous Embedded Packet Capture from Two Interfaces Configuration Example
01-Aug-2013
Configuration Guides
IP Routing EIGRP Configuration Guide, Cisco IOS Release 15SY
30-Apr-2018
IP Routing: OSPF Configuration Guide, Cisco IOS Release 15SY
05-May-2017
Managing Configuration Files Configuration Guide, Cisco IOS Release 15SY
13-Sep-2016
IP Routing: ISIS Configuration Guide, Cisco IOS Release 15SY
01-Sep-2016
Metadata Configuration Guide Cisco IOS Release 15SY
22-Dec-2014
Securing the Data Plane Configuration Guide Library, Cisco IOS Release 15SY
22-Dec-2014
IP Routing: RIP Configuration Guide, Cisco IOS Release 15SY
22-Dec-2014
IP Addressing Services Configuration Guide Library, Cisco IOS Release 15SY
14-Dec-2014
Multiprotocol Label Switching Configuration Guide Library, Cisco IOS Release 15SY
22-Sep-2014
Software Activation Configuration Guide, Cisco IOS Release 15SY
30-Mar-2014
Software Modularity Installation and Configuration Guide, Cisco IOS Release 15SY
05-Oct-2013
IP Routing: LISP Configuration Guide, Cisco IOS Release 15SY
17-May-2013
IP Routing: ODR Configuration Guide, Cisco IOS Release 15SY
06-Dec-2012
First Hop Redundancy Protocols Configuration Guide, Cisco IOS Release 15SY
19-Oct-2012
IP Switching Configuring Multicast Distributed Switching Configuration Guide, Cisco IOS Release 15SY
17-Oct-2012
View all documentation of this type
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