> Source: [sk180106](https://support.checkpoint.com/results/sk/sk180106)

# sk180106 - The "tcpdump -C" command fails with the "Permission denied" error

| Property | Value |
|----------|-------|
| Solution ID | sk180106 |
| Date Created | 2022-10-17 |
| Last Modified | 2022-10-18 |
| Technical Level | Advanced |
| Products | Security Gateway, Security Management Server |
| Versions | R82.10, R82, R81.20, R82.10, R82, R81.20 |
| OS | Gaia |

## Symptoms

- Executing tcpdump with -C syntax returns the following error:  
`tcpdump -enni eth0 -C 20 -W 1 -w test.pcap`  
`tcpdump: test0: Permission denied `

-C: used to limit the file size  
-W: Used in conjunction with the -C option to specify the limit of the rotated files  
-w: Write the raw packets to file

## Cause

In Linux kernel 2.6, the tcpdump tool runs without root permission. A privilege escalation is required.

## Solution

This solution requires authentication. Please log in to view the full solution.

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