King Computer Solutions

Posts Tagged Firewall


Asterisk audio inbound or outbound not working when iptables firewall enabled

Due to attempted hacks on VOIP boxes we need to increase security by allowing SIP access only from the relevant IPs using iptables firewall In the case below the Asterisk VOIP server is sitting behind a NAT firewall and has the relevant config set for this. I found upon enabling the linux firewall that while […]


[DBNETLIB][ConnectionOpen (Connect()).]SQL server does not exist or access denied

This may be due to a firewall issue – in particular Allow inbound SQL Server Browser UDP 1434 See further info on opening relevant firewall ports here: Regards, Brendan


Editing firewall.local settings in Linux CentOS

Short method: Login as the root user – I use putty for windows to connect to the linux server from my desktop after logging in enter-


RDP to Internal server or workstation through ISA firewall

To setup a firewall rule to enable access through ISA to internal servers, you need to map different external ports to the interal port 3389. In this example an internal system is on 192.168.10, and you want to RDP on port 3390 to this server. Right-click firewall policy and select new – server publishing rule […]


Allow inbound echo request (ping) in sbs windows firewall policy

Dsa.msc > Right click-


Active FTP vs. Passive FTP and firewall issues

The Basics FTP is a TCP based service exclusively. There is no UDP component to FTP. FTP is an unusual service in that it utilizes two ports, a ‘data’ port and a ‘command’ port (also known as the control port). Traditionally these are port 21 for the command port and port 20 for the data […]


Got a Billion BiPAC 7404VGP? Can’t access a website?

We couldn’t get to google maps today. We recently adjusted the firewall seetings in our BiPAC 7404VGP but didn’t make any changes that should have affected google maps. Looking at Status / Event Log showed me that an address with a Source Port of 80 was being blocked by a blacklist. By going into the […]


Blocking streaming media ports in a firewall

After being hit with a few $700 and $800 excess charges by Telstra, who refuse to do anything about it and provide no warning system (they make more money that way) I was having a hard time figuring out how-