Asterisk with ip alias

I have two ip address and want to setup two sip trunks and assign to each one of them an ip address eth0/eth0:1 to register with the same fourinsseur with a single IP address:
TRKSIP1 TRUNK -> eth0: =
TRKSIP2 TRUNK -> eth0:1 =
to register with same provider VORP

NB: IPs juste an exemple
thank you for help

You will need an instance of Asterisk for each address!

What are you trying to work round? Is it using an ITSP aimed at bome users?

thank you very much david for your answer,
I already have a trunk with the provider and I want to add another trunk, and the provider requires a different IP address because he can not run both traffic on the same trunk for reasons of billing.

Find an ITSP without that restriction. It does rather sound as though they provide single phone accounts. Asterisk is not designed to cope with that case. You will need to run multiple instances of Asterisk and somehow get them to talk to each other.