1. Generating a TAC-PAC Log Bundle

The TAC-PAC (tac-pac snapshot logs) command collects comprehensive diagnostic information from an NX-OS switch. This is commonly requested by Cisco TAC for troubleshooting.

Command:

tac-pac snapshot logs bootflash:tac_pac_$(SWITCHNAME)_$(TIMESTAMP).gz

• $(SWITCHNAME) → the hostname of your switch.

• $(TIMESTAMP) → automatically replaced with date and time.

• File is stored in bootflash: by default.

Example:

T10PHGXINLFSW01# tac-pac snapshot logs bootflash:tac_pac_$(SWITCHNAME)_$(TIMESTAMP).gz
Show tech detail can take more than 5 minutes to complete. Please Wait ...
Probable snapshot size: 354 MB. Free space available 7494 MB
Snapshot generated at logflash:evt_log_snapshot/tac_snapshot_bundle.tar Please cleanup once done.

2. Verifying Where the Log is Stored

After generation, confirm the file using:

dir bootflash:

Example output:

394257371    Sep 25 11:39:08 2025  tac_pac_T10PHGXINLFSW01_2025-09-25-11.28.34.gz

So the log file is located at:

bootflash:tac_pac_T10PHGXINLFSW01_2025-09-25-11.28.34.gz

3. Enabling SCP Server on NX-OS

By default, the SCP feature may be disabled. To enable:

configure terminal
feature scp-server
end

Verify:

show feature | include scp
scpServer              1          enabled

4. Copying the Log to Your Computer

4.1 From Linux/macOS

Use scp:

scp -O admin@<SWITCH_IP>:tac_pac_<SWITCHNAME>_<TIMESTAMP>.gz ~/Downloads/

Example:

scp -O admin@10.152.15.10:tac_pac_T10PHGXINLFSW01_2025-09-25-11.28.34.gz ~/Downloads/

4.2 From Windows PowerShell (OpenSSH)

Use scp with the -O option (forces legacy SCP mode, required for NX-OS):

scp -O admin@10.152.15.10:tac_pac_T10PHGXINLFSW01_2025-09-25-11.28.34.gz .

This saves the file in the current directory.