Voici ma configuration

J'ai exactement le même modem que toi 510 (1 port), il gère (en DHCP) un petit lan de 3 postes connectés à un switch.
La version de mon firmware est la 4.2.3.0.0. 
Voici mon fichier de configuration (j'ai moi aussi utilisé l'option easysetup au début)
[ language.ini ]
config language=fr
[ script.ini ]
add name=autopvc_add_qos index=0 command="qosbook add name _auto_1ドル_2ドル class 3ドル tx_peakrate 4ドル tx_sustrate 5ドル tx_maxburst 6ドル rx_peakrate 4ドル rx_sustrate 5ドル rx_maxburst 6ドル dynamic yes"
add name=autopvc_delete_qos index=0 command="qosbook delete name _auto_1ドル_2ドル"
add name=autopvc_add_bridge index=0 command="qosbook add name _auto_1ドル_2ドル class 3ドル tx_peakrate 4ドル tx_sustrate 5ドル tx_maxburst 6ドル rx_peakrate 4ドル rx_sustrate 5ドル rx_maxburst 6ドル dynamic yes"
add name=autopvc_add_bridge index=1 command="phonebook add name _auto_1ドル_2ドル addr 1ドル.2ドル type any dynamic yes"
add name=autopvc_add_bridge index=2 command="bridge ifadd intf _auto_1ドル_2ドル dest _auto_1ドル_2ドル"
add name=autopvc_add_bridge index=3 command="bridge ifconfig intf _auto_1ドル_2ドル qos _auto_1ドル_2ドル"
add name=autopvc_add_bridge index=4 command="bridge ifattach intf _auto_1ドル_2ドル"
add name=autopvc_delete_bridge index=0 command="bridge ifdetach intf _auto_1ドル_2ドル"
add name=autopvc_delete_bridge index=1 command="bridge ifdelete intf _auto_1ドル_2ドル"
add name=autopvc_delete_bridge index=2 command="phonebook delete name _auto_1ドル_2ドル"
add name=autopvc_delete_bridge index=3 command="qosbook delete name _auto_1ドル_2ドル"
add name=autopvc_add_pppoerelay index=0 command="qosbook add name _auto_1ドル_2ドル class 3ドル tx_peakrate 4ドル tx_sustrate 5ドル tx_maxburst 6ドル rx_peakrate 4ドル rx_sustrate 5ドル rx_maxburst 6ドル dynamic yes"
add name=autopvc_add_pppoerelay index=1 command="phonebook add name _auto_1ドル_2ドル addr 1ドル.2ドル type any dynamic yes"
add name=autopvc_add_pppoerelay index=2 command="ethoa ifadd intf _auto_1ドル_2ドル dest _auto_1ドル_2ドル"
add name=autopvc_add_pppoerelay index=3 command="ethoa ifconfig intf _auto_1ドル_2ドル qos _auto_1ドル_2ドル"
add name=autopvc_add_pppoerelay index=4 command="ethoa ifattach intf _auto_1ドル_2ドル"
add name=autopvc_add_pppoerelay index=5 command="ip ifwait intf _auto_1ドル_2ドル timeout 15 adminstatus up"
add name=autopvc_add_pppoerelay index=6 command="pppoe relay add port _auto_1ドル_2ドル"
add name=autopvc_delete_pppoerelay index=0 command="pppoe relay delete port _auto_1ドル_2ドル"
add name=autopvc_delete_pppoerelay index=1 command="ethoa ifdetach intf _auto_1ドル_2ドル"
add name=autopvc_delete_pppoerelay index=2 command="ethoa ifdelete intf _auto_1ドル_2ドル"
add name=autopvc_delete_pppoerelay index=3 command="phonebook delete name _auto_1ドル_2ドル"
add name=autopvc_delete_pppoerelay index=4 command="qosbook delete name _auto_1ドル_2ドル"
add name=autopvc_change_qos index=0 command="$1ドル ifdetach intf 2ドル"
add name=autopvc_change_qos index=1 command="$1ドル ifconfig intf 2ドル qos 3ドル"
add name=autopvc_change_qos index=2 command="$1ドル ifattach intf 2ドル"
add name=autopvc_change_qos_pppoerelay index=0 command="ethoa ifdetach intf 1ドル"
add name=autopvc_change_qos_pppoerelay index=1 command="ethoa ifconfig intf 1ドル qos 2ドル"
add name=autopvc_change_qos_pppoerelay index=2 command="ethoa ifattach intf 1ドル"
add name=autopvc_change_qos_pppoerelay index=3 command="pppoe relay add port 1ドル"
add name=autopvc_change_qos_pppoeethoa index=0 command="ethoa ifdetach intf 1ドル"
add name=autopvc_change_qos_pppoeethoa index=1 command="ethoa ifconfig intf 1ドル qos 2ドル"
add name=autopvc_change_qos_pppoeethoa index=2 command="ethoa ifattach intf 1ドル"
add name=autopvc_change_qos_pppoeethoa index=3 command="pppoe ifattach intf 3ドル"
add name=autopvc_change_qos_pppoa index=0 command="pppoa ifdetach intf 1ドル"
add name=autopvc_change_qos_pppoa index=1 command="ip ifwait intf 1ドル timeout 5 adminstatus down"
add name=autopvc_change_qos_pppoa index=2 command="pppoa ifconfig intf 1ドル qos 2ドル"
add name=autopvc_change_qos_pppoa index=3 command="pppoa ifattach intf 1ドル"
[ env.ini ]
set var=CONF_REGION value=World
set var=CONF_PROVIDER value=Basic
set var=CONF_DESCRIPTION value="Routed PPPoE Packet Service configuration using always-on session connectivity."
set var=CONF_SERVICE value="Routed PPPoE - DHCP - NAPT"
set var=CONF_DATE value="Configuration modified manually"
set var=CONF_TPVERSION value=1.2.0
set var=HOST_SETUP value=auto
set var=UPGRADE_URL value=http://www.speedtouch.com/upgrade500.htm(...)
set var=ATM_addr value=8.35
set var=ATM_auto value=active
set var=PPP_user value=fti/*************
set var=dummy value=***********
set var=CONF_TEMPLATE value=pppoe.tpl
set var=CONF_USR_COMMENT value="Configuration created by Embedded Wizard (profile:active/pppoe.tpl)"
set var=COLUMNS value=80
set var=ROWS value=24
set var=SESSIONTIMEOUT value=999
[ wizard.ini ]
def var=ATM type=grp desc="Specify the details of the Routed PPPoE Packet Service. All information should be provided by your ISP." alias="Routed PPPoE Packet Service"
def var=ATM_addr type=combo grp=ATM desc="Choose a VPI/VCI from the list" alias=VPI/VCI default=8.35 data=0.32,0.33,0.35,0.36,0.37,0.38,0.100,1.32,1.33,1.100,8.35,8.36,8.37,8.48,8.81
def var=ATM_auto type=bool grp=ATM alias=Auto-configured default=active data=passive,active
def var=PPP type=grp desc="Specify the details of the Routed PPP Account. All information should be provided by your ISP." alias="PPP Account Settings"
def var=PPP_user type=string grp=PPP desc="Enter your Internet connection user name." alias="User Name" req=yes
def var=%PPP_pwd type=passw grp=PPP desc="Enter your Internet connection password." alias=Password req=yes max=32
def var=PPP_ac type=string grp=PPP desc="Enter the PPPoE Access Concentrator Name." alias="Access Concentrator"
def var=PPP_service type=string grp=PPP desc="Enter the PPPoE Service Name." alias="Service Name"
def var=ST type=grp desc="Specify user name and password to protect SpeedTouch administrative access." alias="SpeedTouch Security"
def var=%ST_SYS_USERNAME type=string grp=ST desc="Enter user name." alias="User Name"
def var=%ST_SYS_PASSWORD type=passw grp=ST desc="Enter your password." alias=Password max=32
[ snmp.ini ]
config sysContact="Service Provider" sysName="SpeedTouch 510" sysLocation="Customer Premises"
[ phone.ini ]
add name=PVC_1 addr=8*35 type=any
[ qos.ini ]
config format=bytes
add name=default class=ubr
[ oam.ini ]
config clp=1 loopbackid=6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a6a
mode port=dsl0 blocking=enabled
mode port=dsl1 blocking=enabled
mode port=atm2 blocking=enabled
mode port=atm3 blocking=enabled
mode port=aal5 blocking=enabled
mode port=atm5 blocking=enabled
[ pfirewall.ini ]
chain create chain=sink
chain create chain=forward
chain create chain=source
rule create chain=sink index=0 srcintfgrp=!wan action=accept
rule create chain=sink index=1 prot=udp dstport=dns action=accept
rule create chain=sink index=2 prot=udp dstport=bootpc action=accept
rule create chain=sink index=3 prot=icmp icmptype=echo-reply action=accept
rule create chain=sink index=4 prot=udp dstport=snmp log=yes action=count
rule create chain=sink index=5 action=drop
rule create chain=forward index=0 srcintfgrp=wan dstintfgrp=wan action=drop
rule create chain=source index=0 dstintfgrp=!wan action=accept
rule create chain=source index=1 prot=udp dstport=dns action=accept
rule create chain=source index=2 prot=udp dstport=bootps action=accept
rule create chain=source index=3 prot=icmp icmptype=echo-request action=accept
rule create chain=source index=4 prot=udp srcport=snmp log=yes action=count
rule create chain=source index=5 action=drop
assign hook=sink chain=sink
assign hook=forward chain=forward
assign hook=source chain=source
[ label.ini ]
chain create chain=user_labels
[ bridge.ini ]
config age=300 filter=no_WAN_broadcast
[ pptp.ini ]
[ ethoa.ini ]
ifadd intf=ETHoA_1 dest=PVC_1
ifconfig intf=ETHoA_1
ifattach intf=ETHoA_1
[ ipoa.ini ]
[ cip.ini ]
[ pppoerelay.ini ]
add port=ETHoA_1
add port=eth0
[ dhcp.ini ]
config autodhcp=off scantime=10 state=enabled trace=off
policy verifyfirst=on trustclient=on
pool add name=LAN_private
pool config name=LAN_private intf=eth0 poolstart=10.0.0.1 poolend=10.0.0.254 netmask=24 gateway=10.0.0.138 server=10.0.0.138 leasetime=7200
lease add clientid=01:00:10:a4:9d:4c:51 pool=LAN_private addr=10.0.0.3 hostname=monpc
lease add clientid=01:00:80:c8:eb:c3:bf pool=LAN_private addr=10.0.0.2 hostname=deux
lease add clientid=01:00:e0:29:0c:c3:f4 pool=LAN_private addr=10.0.0.1
[ pppoa.ini ]
[ pppoe.ini ]
ifadd intf=PPPoE_1
rtadd intf=PPPoE_1 dst=0.0.0.0/0 src=0.0.0.0/0 metric=1
ifconfig intf=PPPoE_1 dest=RELAY accomp=on dnsmetric=0 addrtrans=pat
ifconfig intf=PPPoE_1 user=fti/*********** password=************* status=up
[ ip.ini ]
config forwarding=on firewalling=on redirects=on sourcerouting=off netbroadcasts=off ttl=64 fraglimit=64 defragmode=always addrcheck=dynamic mssclamping=on
apadd addr=10.0.0.138/24 intf=eth0 addroute=no type=1
ifconfig intf=loop mtu=1500 group=local linksensing=off
ifconfig intf=eth0 mtu=1500 group=lan linksensing=off
ifconfig intf=ETHoA_1 mtu=1500 group=wan linksensing=off
ifconfig intf=PPPoE_1 mtu=1492 group=wan linksensing=off
rtadd dst=255.255.255.255/32 gateway=10.0.0.138
rtadd dst=10.0.0.0/24 gateway=10.0.0.138 type=1
rtadd dst=224.0.0.0/4 intf=eth0
[ autoip.ini ]
ifadd intf=eth0
ifconfig intf=eth0 addr=169.254.141.11 poolstart=169.254.1.1 poolend=169.254.254.254 netmask=16
ifattach intf=eth0
[ eth.ini ]
ifconfig intf=1 type=auto
config intf=1 state=enabled
[ diagnostics.ini ]
config pingtimeout=1000 pingpacketsize=20
[ dnsd.ini ]
domain domain=lan
add hostname=SpeedTouch
start
troff
[ dhcr.ini ]
ifconfig intf=eth0 relay=on
add addr=127.0.0.1 intf=eth0 giaddr=10.0.0.138
[ dhcc.ini ]
config trace=off
[ adslpots.ini ]
config opermode=multimode maxbitspertoneUS=13 trace=off modemoption=00000000000000000000000000000000
[ nat.ini ]
bind application=ESP port=1
bind application=FTP port=ftp
bind application=GRE port=1
bind application=H323 port=h323
bind application=IKE port=ike
bind application=ILS port=ldap
bind application=ILS port=ils
bind application=IP6TO4 port=1
bind application=IRC port=6660 port_end=6670
bind application=JABBER port=5222
bind application=JABBER port=15222
bind application=PPTP port=1723
bind application=RAUDIO(PNA) port=realaudio
bind application=RTSP port=rtsp
bind application=SIP port=sip
create protocol=tcp inside_addr=10.0.0.1:www-http outside_addr=0.0.0.0:www-http foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:2002 outside_addr=0.0.0.0: foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:4662 outside_addr=0.0.0.0:4662 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6881 outside_addr=0.0.0.0:6881 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6882 outside_addr=0.0.0.0:6882 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6883 outside_addr=0.0.0.0:6883 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6884 outside_addr=0.0.0.0:6884 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6885 outside_addr=0.0.0.0:6885 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6886 outside_addr=0.0.0.0:6886 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6887 outside_addr=0.0.0.0:6887 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6888 outside_addr=0.0.0.0:6888 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:6889 outside_addr=0.0.0.0:6889 foreign_addr=0.0.0.0:0
create protocol=udp inside_addr=10.0.0.2:8758 outside_addr=0.0.0.0:13352 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.2:13910 outside_addr=0.0.0.0:21564 foreign_addr=0.0.0.0:0
create protocol=udp inside_addr=10.0.0.2:15872 outside_addr=0.0.0.0:1589 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.2:15258 outside_addr=0.0.0.0:38961 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.1:4567 outside_addr=0.0.0.0:4567 foreign_addr=0.0.0.0:0
create protocol=udp inside_addr=10.0.0.2:12734 outside_addr=0.0.0.0:48187 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.2:7959 outside_addr=0.0.0.0:5397 foreign_addr=0.0.0.0:0
create protocol=tcp inside_addr=10.0.0.2:6891 outside_addr=0.0.0.0:6891 foreign_addr=0.0.0.0:0
[ autopvc.ini ]
config mode=active type=pppoerelay opmode=partial overwrite=enabled peakrate=0
[ system.ini ]
setpassword userid=root password=******************* hash2=***********************************
config upnp=enabled mdap=enabled drst=enabled
config dcache=enabled
[ upnp.ini ]
config maxage=1800 defcservice=PPPoE_1 writemode=full safenat=disabled
[ endofarch ]