RHEL 10 must log Internet Protocol version 4 (IPv4) packets with impossible addresses by default.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-281344 | SRG-OS-000420-GPOS-00186 | RHEL-10-800120 | SV-281344r1167182_rule | 2026-03-11 | 1 |
Description
The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects, could be a sign of nefarious network activity. Logging these packets enables this activity to be detected.
Satisfies: SRG-OS-000420-GPOS-00186, SRG-OS-000142-GPOS-00075
ℹ️ Check
Verify RHEL 10 logs IPv4 martian packets by default.
Check the value of the "net.ipv4.conf.default.log_martians" variable with the following command:
$ sudo sysctl net.ipv4.conf.default.log_martians
net.ipv4.conf.default.log_martians = 1
If "net.ipv4.conf.default.log_martians" is not set to "1" or is missing, this is a finding.
✔️ Fix
Configure RHEL 10 to log martian packets on IPv4 interfaces by default.
Create a configuration file if it does not already exist:
$ sudo vi /etc/sysctl.d/99-ipv4_log_martians.conf
Add the following line to the file:
net.ipv4.conf.default.log_martians=1
Reload settings from all system configuration files with the following command:
$ sudo sysctl --system