Prendendo spunto dai file del TG788 sono riuscito ad abilitare la rete guest anche sul firmware Tiscali.
La rete guest, una volta fatte le modifiche ai file di configurazione, è configurabile anche da GUI (di Ansuel).
Posto qui quello che ho aggiunto ai vari file, nel caso possa servire a qualcuno.
/etc/config/network
config interface 'guest'
option proto 'static'
option type 'bridge'
option ipv6 '0'
option ip6hint '1'
option netmask '255.255.255.0'
option ipaddr '192.168.123.1'
list ifname 'wl0_1'
option force_link '0'
/etc/config/dhcp
config dhcp 'guest'
option interface 'guest'
option start '2'
option leasetime '12h'
option dhcpv6 'server'
option ra 'server'
option ra_management '0'
option ra_mininterval '200'
option ra_maxinterval '600'
option ra_lifetime '1800'
option ra_hoplimit '64'
option ra_max_mtu '1500'
option force '1'
option ignore '0'
list dhcp_option 'tag:cpewan-id,vi-encap:3561,6,"MediaAccess TG789vac v2"'
list dhcp_option 'tag:cpewan-id,vi-encap:3561,5,"CP1850RAGHB"'
list dhcp_option 'tag:cpewan-id,vi-encap:3561,4,"A491B1"'
list dhcp_option '6,192.168.1.1'
option limit '125'
/etc/config/firewall
config zone 'guest'
option name 'guest'
list network 'guest'
option input 'ACCEPT'
option output 'ACCEPT'
option forward 'ACCEPT'
option wan '0'
config forwarding 'guest_wan'
option src 'guest'
option dest 'wan'
option name 'guest2wan'
option enabled '1'
config rule 'allow_guest_dhcp'
option name 'allow_guest_dhcp'
option src 'guest'
option family 'ipv4'
option proto 'udp'
option dest_port '67'
option target 'ACCEPT'
config rule 'allow_guest_dns'
option name 'allow_guest_dns'
option src 'guest'
option family 'ipv4'
option proto 'udp'
option dest_port '53'
option target 'ACCEPT'
/etc/config/wireless
config wifi-iface 'wl0_1'
option network 'lan'
option device 'radio_2G'
option state '1'
option reliable_multicast '0'
option mode 'ap'
option ssid 'TG789-Guest'
config wifi-ap 'ap2'
option wsc_state 'configured'
option acl_mode 'unlock'
option max_assoc '5'
option ap_isolation '1'
option wps_ap_pin '26487825'
option wps_ap_setup_locked '0'
option station_history '1'
option acl_registration_time '60'
option trace_level 'some'
option pmf 'disabled'
option iface 'wl0_1'
option public '1'
option wps_state '0'
option pmksa_cache '1'
option wps_w7pbc '0'
option state '1'
option wep_key '##chiavewep##'
option security_mode 'wpa-wpa2-psk'
option wpa_psk_key '##chiavewpa##'
config wifi-radius-server 'ap2_auth0'
option state '0'
option port '1812'
option priority '3'
option secret '##secret (copiato da rete non guest, non so se serva)##'
config wifi-radius-server 'ap2_acct0'
option state '0'
option port '1813'
option priority '3'