Mirror DF flag in ICMP echo replies
From: Davis Mosenkovs <hidden>
Date: 2024-08-02 22:54:24
From: Davis Mosenkovs <hidden>
Date: 2024-08-02 22:54:24
Greetings! Currently, after receiving an IPv4 ICMP echo request packet with the Don't Fragment (DF) flag set in the IP header, a Linux node sends an ICMP echo response packet without the DF (Don't Fragment) flag. Some other operating systems (e.g. some commercial network devices) mirror the DF flag in ICMP echo responses (ICMP echo responses have the same value of the DF flag as the received ICMP echo requests had). Would such feature (mirroring DF flag value in ICMP echo reply packets) be welcome in the Linux kernel? If yes, should it be configurable via a sysctl named icmp_echo_mirror_df (under /proc/sys/net/ipv4) with 0 (off - the current behavior) as the default? Best regards, Davis Mosenkovs