Dear Maintainer, just as a side note, a similar bug was submitted against the basilisk2 package.
https://bugs.debian.org/922323
Another user of slirp is qemu, which had some changes in
that area, which seems to have evolved into this library:
https://gitlab.freedesktop.org/slirp/libslirp
https://gitlab.freedesktop.org/slirp/libslirp/blob/master/src/ip.h#L214
Kind regards,
Bernhard
