SSHD restart

AIX

stopsrc -s sshd
startsrc -s sshd

HP-UX

/sbin/init.d/secsh stop
/sbin/init.d/secsh start

RHEL/OEL

service sshd restart

or

/etc/init.d/sshd restart

SUSE

/etc/rc.d/sshd restart

Solaris

svcadm disable ssh
svcadm enable ssh