Alterar o TTL no sistema operacional Windows.
HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters
DefaultTTL DWORD dectimal 129 or Hex 81
Reinicie o SO.
TTL129.reg:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters]
"DefaultTTL"=dword:00000081
Reinicie o SO.
TTL-Restore.reg:
Windows Registry Editor Version 5.00
[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\services\Tcpip\Parameters]
"DefaultTTL"=-
Reinicie o SO.
Restaurar padrão, excluir DefaultTTL.
Defina o TTL 128 no Dlink DIR-300, se possível.
iptables -t mangle -I POSTROUTING -o 'get_wanface' -j TTL --ttl-set 128
iptables -t mangle -I PREROUTING -i vlan1 -j TTL --ttl-set 129
Comando Iptables do DD-WRT wiki
Alterar o ISP ...