Maybe your firewall blocks it or hosts are wrong..
Check them to be sure C:\WINDOWS\system32\drivers\etc
It has to be like that
127.0.0.1 vip.towalker.com
127.0.0.1 vip1.towalker.com
127.0.0.1 vip2.towalker.com
127.0.0.1 vip3.towalker.com
127.0.0.1 vip4.towalker.com
127.0.0.1 vip5.towalker.com
127.0.0.1 vip6.towalker.com
127.0.0.1 vip7.towalker.com
If nothing changes turn off yout firewall to see if it works
And start La2 from the RUN buton of walker and not of l2.exe.