1 - Is it possible to send to a remote syslog-ng server a particular log file, for example the following /var/log/network.log, and how we can do this?

iface eth1 inet dhcp
    ...
    up echo $IFACE up $(date) >> /var/log/network.log
    down echo $IFACE down $(date) >> /var/log/network.log

2 - Is it possible to log in real time a change occured a network interface ? For example a new open port. More generally, how can we log actions naturally not covered by syslog-ng in order to send to a remote server?