Spare local IP address - not physical alias

[Andrew P.]

Hello!

I have people connecting to my server via ppp. When
they establish connection the server gets 172.18.0.1
and they get 172.18.0.x. A dns server is running on
172.18.0.1.

The problem is that sometimes there are no ppp
connections, and the server does not have the
172.18.0.1 address. But I want applications to be
able to query this very address and get answers.
Is there a totally secure way to set up a permanent
address?


Thanks!

Best wishes,
Andrew P.