admin panel on port 2030 in CWP is not opening

Question

I have dedicated server with centos and proxmox ve. Also made virtual machine with centos 6 and centos webpanel in proxmox. From last four month I'm using this and everything is working properly mean I'm able to open mysite:2030 (admin panel). But from today morning, it is not opening, I don't know why is this happening. But I'm able to access all files through ftp(21) and also able to access sftp(22). Please help me configuring it so I will able to open admin panel(Control Panel).Thanks.

Solution

After trying so many methods I searched on net related iptables, I got one best solution, now everything is working like a charm. And applied below command with root access using putty.

1)First I tried this commands:

iptables -A INPUT -p tcp --dport 2030 -j ACCEPT //press enter
service iptables restart //press enter

2)then below commands:

iptables -I OUTPUT -p tcp --dport 2030 -j ACCEPT //enter
/etc/init.d/iptables stop //enter
/etc/init.d/iptables start //enter
reboot //rebooted server