Hi,
all of `dhcp daemon (server)`, `tcpdump (diagnosis)` and
`systemd-networkd (client)`
show value of xid (DHCP Option 61) in a same format (big-endian, i think).

but dhclient (4.2.5 Centos-7-x86_64.1708) shows in different (little
endian i guess),
act as a special dhcp client.

all machines is x86_64 (little endian),
although they shows in big endian what i do not know why,
but, would dhclient add a way to configure display of dhcp xid ?
or let a xid parameter stuff enabled for end user

such as ISC DHCP change log "Changes since 4.3.3" said:

- Added a parameter, authoring-byte-order, to the lease file. This value
  is automatically added to the top of new lease files by the server and
  indicates the internal byte order (big endian or little endian) of the
  server.  This permits lease files generated on a server with one form of
  byte order to be used on a server with the opposite form. Our thanks to
  Timothe Litt for calling this to our attention and for the suggestions
  he provided.  [ISC-Bugs #38396]

sorry to email to both bugs and suggest,
because i do not know this is a bug or suggest,
and no github page of you found,
and sign up of https://bugs.isc.org seems closed.