PPPoE and multiple static public ip

My provider is giving internet connection with 8 public ip over PPPOE

the info he told me are something like:
public ip: (netmask
(broadcast: available public ip: to
dns: (and/or others like )
pppoe user: user@provider.it
password: password
vlan: 835

At present I am cascading 2 routers:
-the first router makes the pppoe connection
(and dynamically gets settings like that on wan:
pppoe wan ip
dns: ,
checking with a browser my public ip gets something like:
its lan is configured as a network
and goes to the second router wan.
-the second router has multiple static ip on the wan:,,,,,
and routes to my lan (

with such configuration everything works fine,
I can set selective firewall rules that allow my servers in the lan to exit and
accept connection from the public ip of my choice

Now the question: How can I get rid of the first router?

I tried to mix the pppoe config and multi static ip in /etc/config/network
in this way unsuccessfully:

config interface 'wan'
	option force_link '0'
	option ipv6 '0'
	option delegate '0'
	option device 'eth0.835'
	option proto 'pppoe'
	option username 'user@provider.it'
	option password 'password'
	option vlanid '835'
	option disabled '0'
	option peerdns '0'
	list dns ''
	list dns ''
	list dns ''
	option gateway ''
	list ipaddr ''
	list ipaddr ''
	list ipaddr ''
	list ipaddr ''
	list ipaddr ''

You can easily run pppoe on the second router and setup the additional wan aliases.