Week 7 Blog

Dynamic Host Configuration

Dynamic Host Configuration Protocol

Linux can both use dynamic host configuration protocol (DHCP) to get network information and be used to act as a DHCP server. These types of servers can grab addresses from a pool when it’s requested. Additionally, Locations of DNS servers and default internet gateways are distributed. Now get ready for the borderline confusing setting and configuration for a DHCP server.

Manual IP Configuration

There’s four fields that need to be set after the network configuration tool is launched. These four are:

·         IP address – This can be left alone or be set manually. A static IP address of machines has an IP address that does not change even after reboot.

·         Subnet mask – The subnet mask is responsible for getting the range of addresses for the computers and devices on the LAN or subnet.

·         Default gateway – Whenever the need to leave your LAN, the request needs to figure out what node on the subnetwork will route to outside the LAN. The gateway can route the requests for IP addresses that are outside of the local subnet.

·         Domain name system (DNS) – It’s hard for people to remember IP address in full so we give them host names. The DNS translates this so when we do something with a host name the system sees it as an IP address.

Configuring a DHCP Client

There’s four important network parameters that need to be set when setting up a DHCP server. Lease time is a time set for clients for how long they can use the IP address from the DHCP server. This lease can be renewed if the client makes a request. Without any configuration, the lease time is set at 86,400 seconds, which is 24 hours. Host workstations can be assigned a name with the use of DHCP as well. The configuration file is found under /etc/dhcp/dhclient.conf. Typically, the DHCP client configuration file doesn’t need to be touched, but it’s good to know how everything works, specially setting the parameters.

Configuring a DHCP Server

Installing the DHCP package is the first step to setting up a DHCP server. Next is making sure that the firewall is allowing communication through the two UDP ports 67 & 68. The next is opening and editing the configuration file found under /etc/dhcp/dhcpd.conf. Once your parameters are set it’s time to launch the dhcpd server daemon. The next two steps are to set up the host firewall, and then the DHCP configuration file under /etc/dhcp/dhcpd.conf. After your parameters are set you are done (after testing of course).

Week 6 Blog

DBMSs and Programming Languages

Databases and programming languages are what makes websites so special. We used HTML a little last week and it was very primitive. Most websites now are connected to databases in order to retrieve and store information. Programming allows features like usernames/passwords, security, and most visual aspects. Web servers are responsible for loading the index/home page, access the database to retrieve data, and sends the information to the client. Programming languages allow the website to be able to communicate to the web server.

Understanding the Database Management Systems (DBMs) Architecture

There’s a lot to DBMs, but most of it’s easy to understand. Let’s start with the clients. There’s the database administrator, web server, and anyone that is trusted. Anytime the database needs maintenance performed it needs to be done by the database administrator. Servicing the database outside of the company’s local area network can cause security issues because if you can access it outside, then somebody else can. The web server allows the web page to construct dynamic web pages by accessing the database once a web client requests the page. Database servers don’t need to be directly connected to internet. Developers can just access the database through the web server.

MySQL Configuration

The database management system we talked about this lesson was MySQL., which is specifically a relational database.  Relational database structures information to other comparative information. MySQL is highly modifiable. The main configure file is the my.cnf file. I mentioned earlier about remote access to the database server. To you can turn off that feature with the main configuration file. Once that’s done, you’ll create a root password and administrator account in MySQL. If the MySQL server package isn’t downloaded, then type sudo dnf -y install mysql-server into the terminal. This will also install MySQL users and groups. Set up passwords for the users and allow certain permissions for certain groups as a security protocol. An average Joe shouldn’t be able to make huge changes to the database. Here is how you drop the users: mysql> drop user ''@localhost;. If you need to exit MySQL enter in this command mysql> exit;.