dhclient vs aliases

Apologies if this is a FAQ and maybe it has always been like that but I've just 
noticed this.

A switch needed to be rebooted, so on a FreeBSD host a link went down and then 
up on an interface connected to the switch.
Apparently triggered by those events, dhclient decided to renew the interface's
IP address. Afterwards, all alias IP addresses on that interface were cleared.
Just in case, the new IP address was exactly the same as the old IP address 
(it's "hardwired" in the DHCP server configuration).

This was unhelpful because the host runs a number of jails with a simple IP 
configuration via aliases.

-- 
Andriy Gapon