SystemPrivileged EXEC

show version

Displays system hardware and software information, including IOS version, uptime, memory, interfaces, and configuration register, used to verify device identity and software compatibility.

Syntax·Privileged EXEC

show version

When to Use This Command

Check the IOS version and feature set before upgrading or troubleshooting.
Verify device uptime to confirm when it last rebooted.
Determine the amount of DRAM and flash memory for capacity planning.
Check the configuration register value to understand boot behavior.

Command Examples

Basic show version output

show version

Cisco IOS Software, C1900 Software (C1900-UNIVERSALK9-M), Version 15.7(3)M3, RELEASE SOFTWARE (fc2)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2019 by Cisco Systems, Inc.
Compiled Mon 04-Mar-19 15:32 by prod_rel_team

ROM: System Bootstrap, Version 15.7(1r)M1, RELEASE SOFTWARE (fc1)

Router uptime is 2 weeks, 3 days, 14 hours, 22 minutes
System returned to ROM by power-on
System image file is "flash0:c1900-universalk9-mz.SPA.157-3.M3.bin"
Last reload type: Normal Reload

This product contains cryptographic features and is subject to United
States and local country laws governing import, export, transfer and
use. Delivery of Cisco cryptographic products does not imply
third-party authority to import, export, distribute or use encryption.
Importers, exporters, distributors and users are responsible for
compliance with U.S. and local country laws. By using this product you
agree to comply with applicable laws and regulations. If you are unable
to comply with U.S. and local laws, return this product immediately.

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

Cisco CISCO1941/K9 (revision 1.0) with 487424K/49152K bytes of memory.
Processor board ID FTX1636848Z
2 Gigabit Ethernet interfaces
2 Serial interfaces
1 Virtual Private Network (VPN) Module
DRAM configuration is 64 bits wide with parity enabled.
255K bytes of non-volatile configuration memory.
250880K bytes of ATA System CompactFlash 0 (Read/Write)

License Info:
License UDI:

Device# PID SN
*0 CISCO1941/K9 FTX1636848Z

Technology Package License Information for Module:'c1900'
-----------------------------------------------------------------
Technology Technology-package Technology-package
Current Type Next reboot
------------------------------------------------------------------
ipbase ipbasek9 Permanent ipbasek9
security securityk9 Permanent securityk9
uc uck9 Permanent uck9
data datak9 Permanent datak9

Configuration register is 0x2142 (will be 0x2102 at next reload)

Line 1: IOS version and release information. Line 2-4: support and copyright. Line 6: ROM version. Line 8: system uptime. Line 9: reason for last restart (power-on). Line 10: location of the IOS image file. Line 11: last reload type. Lines 13-20: cryptographic export notice. Line 22: model and revision, memory split (DRAM/Flash). Line 23: processor board ID. Line 24: interface count. Line 25: serial interfaces. Line 26: VPN module. Line 27: DRAM width and parity. Line 28: NVRAM size. Line 29: CompactFlash size. Lines 31-35: license UDI. Lines 37-44: technology package licenses and their types (Permanent). Line 46: configuration register value (current and next reload).

Show version with different uptime and memory

show version

Cisco IOS Software, C2960 Software (C2960-LANBASEK9-M), Version 15.2(4)E7, RELEASE SOFTWARE (fc1)
Technical Support: http://www.cisco.com/techsupport
Copyright (c) 1986-2018 by Cisco Systems, Inc.
Compiled Thu 26-Jul-18 14:12 by prod_rel_team

ROM: Bootstrap program is C2960 boot loader

Switch uptime is 1 hour, 5 minutes
System returned to ROM by power-on
System image file is "flash:c2960-lanbasek9-mz.152-4.E7.bin"
Last reload type: Normal Reload

A summary of U.S. laws governing Cisco cryptographic products may be found at:
http://www.cisco.com/wwl/export/crypto/tool/stqrg.html

If you require further assistance please contact us by sending email to
export@cisco.com.

cisco WS-C2960+24TC-L (PowerPC405) processor (revision F0) with 65536K/8192K bytes of memory.
Processor board ID FOC1234X5Y6
Last reset from power-on
1 Virtual Ethernet interface
24 FastEthernet interfaces
2 Gigabit Ethernet interfaces

The password-recovery mechanism is enabled.

64K bytes of flash-simulated non-volatile configuration memory.
Base ethernet MAC Address : 00:1C:58:AB:CD:EF
Motherboard assembly number : 73-12345-06
Power supply part number : 341-0123-01
Motherboard serial number : FOC12345678
Power supply serial number : DTH1234567
Model revision number : F0
Motherboard revision number : A0
Model number : WS-C2960+24TC-L
System serial number : FOC1234X5Y6
Top Assembly Part Number : 800-12345-01
Top Assembly Revision Number : A0
Version ID : V01
CLEI Code Number : ABCDEFG
Hardware Board Revision Number : 0x01

Switch Ports Model SW Version SW Image
------ ----- ----- ---------- ----------
* 1 26 WS-C2960+24TC-L 15.2(4)E7 C2960-LANBASEK9-M

Configuration register is 0xF

This is a switch output. Line 1: IOS version for Catalyst 2960. Line 8: uptime is short (1 hour 5 min). Line 10: image file location. Line 22: model and processor, memory split. Line 23: board ID. Line 24: last reset reason. Line 25: virtual Ethernet interface. Line 26: 24 FastEthernet ports. Line 27: 2 Gigabit ports. Line 29: password recovery status. Line 31: NVRAM size. Line 32: base MAC address. Lines 33-44: hardware details. Lines 46-49: summary table of ports, model, SW version, image. Line 51: configuration register (0xF).

Understanding the Output

The show version output provides a snapshot of the device's identity and health. Key fields: IOS version (e.g., 15.7(3)M3) indicates feature set and release; uptime shows how long since last reboot (good for stability assessment); system image file shows the exact IOS filename for upgrade verification; processor and memory details (e.g., 487424K/49152K bytes of memory) indicate DRAM and flash capacity; interface counts confirm hardware configuration; configuration register (e.g., 0x2102) controls boot behavior (0x2102 loads from flash, 0x2142 ignores startup config). For switches, additional hardware details like MAC address and model number are included. A high uptime suggests stability, while a low uptime may indicate recent issues. The configuration register is critical for password recovery (0x2142) or normal boot (0x2102).

CCNA Exam Tips

CCNA exam tip 1: Know that the configuration register value 0x2102 means the device loads the startup configuration from NVRAM; 0x2142 bypasses startup config (used for password recovery).

CCNA exam tip 2: The 'System returned to ROM by' field indicates the reason for the last reload (e.g., power-on, reload command, or crash).

CCNA exam tip 3: The IOS image filename includes the platform, feature set, and version; e.g., c1900-universalk9-mz.SPA.157-3.M3.bin — 'universalk9' means universal image with crypto.

CCNA exam tip 4: Memory values (e.g., 487424K/49152K) represent total DRAM and memory used for I/O; the first number is main memory, second is packet memory.

Common Mistakes

Mistake 1: Confusing the configuration register value; 0x2102 is normal, 0x2142 bypasses startup config, not the other way around.

Mistake 2: Misinterpreting the memory split; the first number is total DRAM, not available memory.

Mistake 3: Overlooking the 'Last reload type' field; it can indicate if the reload was normal or due to a crash.

Related Commands

show ip interface brief

Displays a summary of all IP interfaces on the device, including their IP address, status, and protocol state, used for quick verification of interface configuration and connectivity.

show running-config

Displays the current active configuration in DRAM, showing all non-default settings.

show startup-config

Displays the saved configuration stored in NVRAM that loads on next device boot.

Practice for the CCNA 200-301

Test your knowledge with hundreds of CCNA practice questions covering all exam domains.

Practice CCNA Questions