TOSS 5 must log IPv4 packets with impossible addresses by default.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-282688 | SRG-OS-000480-GPOS-00227 | TOSS-05-000216 | SV-282688r1201044_rule | 2026-04-01 | 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.
ℹ️ Check
Verify TOSS 5 logs IPv4 martian packets by default using 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 a line is not returned, this is a finding.
✔️ Fix
Configure TOSS 5 to log martian packets on IPv4 interfaces by default.
Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory:
net.ipv4.conf.default.log_martians=1
Load settings from all system configuration files using the following command:
$ sudo sysctl --system