It might be useful to provide an example using POSIX od(1) instead of hexdump(1). hexdump is actually a BSD utility. The Debian Linux version is ported from FreeBSD, while the Red Hat version is a pale imitation provided as a wrapper, IIRC, around the od implementation.[1] `od -An -tu1 -v` should suffice.

[1] I wrote a single-file hexdump implementation so know far too much about it: https://25thandclement.com/~william/projects/hexdump.c.html