If you use dhcp to get the IP on your Arch Linux, you will use the Network DNS server, and that is good, if that DNS server works well, but I have seen in some networks they resolv some addresses to 220.127.116.11, do not know why but to fix this you may do this, if working on Arch.
On /etc/rc.conf file you will have some line like this
and now you must create (if it does not exists) a file named /etc/resolv.conf.head and add there your stuff, something like this
nameserver 18.104.22.168 nameserver 22.214.171.124
This way these nameserver will always be on top of the local DNS, it is maybe a bad idea for speed, but at least you will be sure it will work.