There are several examples of packages installing files to /usr/lib/sysctl.d, but I haven't found any specific guidance on policies about what's appropriate for them. Since sysctl variables change the system behavior in a way that's not limited to the package changing the setting, and since the package in question (iputils-ping) is Priority: important and part of the default install, I won't want to make any changes without consulting here first.
See bug #1008281 for context. [1] The proposal is to install /usr/lib/sysctl.d/iputils-ping.conf with the following content: net.ipv4.ping_group_range="0 2147483647" With that in place, unprivileged users are able to excute ping for both IPv4 and IPv6 targets without cap_net_raw (currently set as either a file-based attribute on the ping binary or acquired via setuid). But since that applies system-wide, not just to the ping binary, there may be objections. After applying this change, I believe it'd be appropriate to drop ping's setcap/setuid settings from postinst altogether, though I'd be open to other options. [2] noah 1. https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=1008281 2. https://salsa.debian.org/debian/iputils/-/blob/master/debian/iputils-ping.postinst
