Scenario / Question: I can not use yum and appears that iptables is blocking yum from establishing a connection with the internet. Solution / Answer: IPTables needs to be configured to allow incoming ESTABLISHED,RELATED connections and establish connection with yum servers by allowing outgoing [continue...]

Scenario / Question: IPTables is blocking DNS and I can not get DNS from Internet. Solution / Answer: IPTables needs to be configured to allow INPUT of port 53 and the OUTPUT of port 53. DNS uses both tcp and udp protocols on port 53 for communicating. UDP is used for queries transferring less [continue...]