I am a rank newbie & out of my element here, but I need to know something:
While perusing journalctl output, the following line appeared repeatedly for a time, and then, after a point in time, it stopped appearing:
... kernel: ICMPv6: process 'dhcpcd' is using deprecated sysctl (syscall) net.ipv6.neigh.wlan0.retrans_time - use net.ipv6.neigh.wlan0.retrans_time_ms instead
dhcpcd is the DHCP client daemon for my (Raspberry Pi OS) system. I concluded (probably incorrectly) that this deprecated syscall was something called out specifically in the dhcpcd source code. In an effort to find that code, I tried this:
$ grep -Ril 'net.ipv6.neigh.wlan0.retrans_time' ~/dhcpcd5
$ # where ~/dhcpcd5 is the 'source package' fetched fm the RPi archives
Unfortunately, this yielded nothing - no match. How do I learn where & how dhcpcd came to use this now-deprecated syscall? Is this the result of my system's kernel being out-of-date - or what?
See here, it should fix the issue: