Half Bridge / PPP Extension

is it possible to edit this so that the modem/router dga4130 does the pppoe but passes wan ip to an asus router in dhcp mode downstream? aka half bridge, PPP IP Extension.

config interface 'loopback'
	option ifname 'lo'
	option proto 'static'
	option ipaddr '127.0.0.1'
	option netmask '255.0.0.0'

config globals 'globals'
	option ula_prefix 'none'
	option default_ps '0'

config device 'waneth4'
	option type '8021q'
	option name 'waneth4'
	option macaddr '10:13:31:*****'
	option ifname 'eth4'
	option vid '835'
	option ipv6 '0'

config interface 'wan'
	option enabled '1'
	option ipv6 '0'
	option password 'password'
	option metric '0'
	option keepalive '4,20'
	option proto 'pppoe'
	option username 'bblah@blah'
	option auto '1'
	option ifname 'ptm0'

config config 'config'
	option wan_mode 'pppoe'

config interface 'wwan'
	option proto 'mobiled'
	option session_id '0'
	option profile '1'
	option enabled '1'
	option auto '0'

config interface 'wan6'
	option ifname '@wan'
	option proto 'dhcpv6'
	option reqopts '12 21 22 23 24 25 31 56 64 67 82 83'
	option noslaaconly '1'
	option iface_464xlat '0'
	option auto '0'
	option dns_metric '20'
	option enabled '1'

config interface 'lan'
	option type 'bridge'
	option proto 'static'
	option ipaddr '192.168.1.1'
	option netmask '255.255.255.0'
	option ip6assign '64'
	option force_link '0'
	option ipv6 '0'
	list pppoerelay 'br-lan'
	list ifname 'eth0'
	list ifname 'eth1'
	list ifname 'eth2'
	list ifname 'eth3'
	list ifname 'eth5'

config switch 'bcmsw'
	option reset '1'
	option enable_vlan '0'
	option qosimppauseenable '0'
	option jumbo '0'

config interface 'wlnet_b_24'
	option proto 'static'
	option ip6assign '64'
	option ipv6 '0'
	option ip6hint '1'
	option netmask '255.255.255.128'
	option ipaddr '192.168.168.1'
	option ifname 'wl0_1'
	option force_link '0'
	option name 'Ospiti-TIM-24068835'

config interface 'wlnet_b_5'
	option proto 'static'
	option ip6assign '64'
	option ipv6 '0'
	option ip6hint '2'
	option netmask '255.255.255.128'
	option ipaddr '192.168.168.129'
	option ifname 'wl1_1'
	option force_link '0'
	option name 'Ospiti-TIM-24068835'

config device 'wlnet_b_5eth5'
	option type '8021q'
	option name 'wl1_1'
	option enabled '1'
	option ifname 'eth5'
	option vid '3'
	option ipv6 '0'

config interface 'ipoe'
	option proto 'dhcp'
	option metric '1'
	option reqopts '1 3 6 43 51 58 59'
	option release '1'
	option neighreachabletime '1200000'
	option neighgcstaletime '2400'
	option ipv6 '1'

config device 'wanptm0'
	option enabled '1'
	option type '8021q'
	option name 'wanptm0'
	option vid '835'
	option ipv6 '0'
	option ifname 'ptm0'