Can not view man page on CentOS

I have been having issues with viewing man page when I logged in as a regular user. Everytime, I have to add sudo in front of man command. After troubleshooting the problem for a while, I found a solution:

Add execute permission for the following folder and its contents

sudo chmod o+x -R /usr/share/man/

Others also suggest that the $MANPATH is incorrect. However, this is not the case for me.

IPtables: open port for specific IP

The following are examples of allow a host or a range of hosts visit port 8080

sudo vim /etc/sysconfig/iptables

# the following rule specifies only Ip 101.2.3.44 can visit port 8080

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -s 101.2.3.44 --dport 8080 -j ACCEPT

# a range of IPs are allowed to visit port 8080

-A RH-Firewall-1-INPUT -m state --state NEW -m tcp -p tcp -src-range 101.2.3.44-1.2.3.54 --dport 8080 -j ACCEPT

# restart iptables service to make the change take effect

sudo /etc/init.d/iptables restart