An over-tuned server is one that is configured to allow more simultaneous requests (ServerLimit) than the server’s hardware can manage. Servers set in this manner have a tipping point, and once reached, the server will become stuck in a perpetual swapping scenario. Meaning the Kernel is stuck rapidly reading and writing data to and from the system swap file.Continue reading “Apache Performance Tuning: Swap Memory”
chkconfig NetworkManager off; service NetworkManager stopStep 2: The method for permanent changes is to edit the /etc/sysconfig/network-scripts/ifcfg-eth0 file instead of resolv.conf file. Open the file:
vim /etc/sysconfig/network-scripts/ifcfg-eth0Next, we’ll set our DNS IP’s to use Google’s Public DNS (220.127.116.11 & 18.104.22.168).
DEVICE="em1" BOOTPROTO="static" DNS1="127.0.0.1" DNS2="22.214.171.124" DNS3="126.96.36.199" GATEWAY="some_ip" HWADDR="hwid" IPADDR="some_ip" IPV6INIT="yes" NETMASK="255.255.255.0" NM_CONTROLLED="yes" ONBOOT="yes" TYPE="Ethernet"Save and quit the file using ESC and :wq. Step 3: Enable and restart your network, using the commands associated with your server version. CentOS 6, CloudLinux 6, RHEL 6:
chkconfig network on
service network startCentOS 7, CloudLinux 7, RHEL 7:
systemctl enable network.service
systemctl start network.serviceStep 4: Test the reachability of a host by using ping, curl, wget or any testing tool of your choice. In our example, we’ve successfully ping’d Google!
ping google.com PING google.com (188.8.131.52) 56(84) bytes of data. 64 bytes from lga15s46-in-f14.1e100.net (184.108.40.206): icmp_seq=1 ttl=57 time=6.65 ms 64 bytes from lga15s46-in-f14.1e100.net (220.127.116.11): icmp_seq=2 ttl=57 time=6.68 ms 64 bytes from lga15s46-in-f14.1e100.net (18.104.22.168): icmp_seq=3 ttl=57 time=6.68 msYou don’t have to rack your brain over connectivity issues! Liquid Web customers enjoy 24/7 support for our VPS Managed products. Our knowledgeable team of support techs have experience with solving errors of this nature. Access our support team through a ticket, chat or phone call!
What is DNS?If you are new to web hosting, you may have heard the term DNS, but you might not be sure what it means or how it is essential to you. DNS is short for Domain Name System, and it is the process by which the whole Internet organizes and easier way for humans to reach websites. Numbers or IP addresses identify all of the computers/websites connected to the Internet. While computers have no trouble identifying each other using these strings of numbers, it would be challenging for humans if we had to remember a set of numbers for every website we wanted to visit! Fortunately, DNS translates domain names like liquidweb.com to an IP address and back, so all we need to know to find a website is the name. For a more in-depth discussion of the DNS system, see Understanding the DNS Process. You can use the DNS Tree for a quick, visual comparison of the records that exist on all of your nameservers. Making sure your records match across nameservers and that they match your server is an essential part of troubleshooting possible website issues. If you’re error messages like “This site can’t be reached” or “webpage is not available”, the DNS Tree may help you figure out where the problem exists.
How Do I Check My DNS?Verifying accurate DNS records is essential for navigating traffic to the correct web server. You can use Liquid Web’s Internet Webhosting Toolkit to view your current, authoritative DNS records. Just go to the toolkit’s site, click on the DNS Tree tab, enter your domain name, and click Submit.
If you have registered your domain and set DNS records our tool will display the results in an easy to see “tree” of records, organized from most general to most specific.
In our example, we are looking up the records for liquidweb.com, so the tree begins with that domain at the far left of the screen.
The next set of records displayed are the Authoritative Nameservers for the domain. These are the servers designated as the holders of the records for this domain. If you want to change the records for this domain, you must change them on these servers. Changing records anywhere else won’t make reflect DNS changes. Your domain can have one, two, or as many Authoritative Nameservers as you would like but most websites use at least two for redundancy and stability.
The next set of entries in the DNS Tree show the Types of records that are available. DNS record types are unique for each kind of DNS function.
- An “A Record” is used to identify primary IP addresses of given domains.
- “MX Records” are used for email routing and delivery.
- “TXT records” hold additional information about the domain, like SSL validations, DKIM entries, or SPF records.
The final “column” of entries displays the actual DNS record. This is typically an IP address for an “A record”, and domain name for an “MX record”, or a string of text for a “TXT record”. Hovering the mouse over a circle will display all of the information for the record in a pop-out window, including the TTL, Type, and Data.
If you’ve made recent changes to your DNS records, the toolkit may be showing an older, or cached, version of the records. The TTL portion of the record indicates how frequently the DNS system should update its records. TTL is shown in seconds, so a typical setting of 3600 means that servers will be asked to update your records every 6 minutes. The delay that occurs during this period is referred to as propagation. Some DNS changes, like nameserver changes, can take up to 72 hours to propagate, so if you are going to be making changes to your DNS records, you’ll want to lower your TTL values for a quick update. For more information on reducing your TTLs, see How To: Lowering Your DNS TTLs. If you need additional help, Liquid Web customer’s can contact the Most Helpful Humans in Hosting via ticket, chat, or phone (1-800-580-4985) at any time and we’ll do our best to make sure everything is working correctly.
How Do I Get Back Into RDP?
You may be working from a local machine that has an IP that is not scoped on that RDP port, making it impossible for you to gain remote access to add the IP address to the RDP rule’s scope. Do not fret; there is a simple and quick way to add your IP to the RDP scoping (or any other entities such as MySQL or MSSQL) right through your Plesk interface in your local browser. You can watch this video, or scroll down for step-by-step directions.
For security purposes, it is always recommended that you scope off your Remote Desktop Protocol (RDP) connection on your server. Putting a scope on the RDP rule in the Windows Firewall will allow only the indicated IP addresses to gain access to the server through Remote Desktop Protocol. The issue is that many of us do not have static IP addresses, but rather Dynamic IP addresses. This means that while once our IP address may be 120.32.111.01, it may change to something like 95.42.121.01 later. So if you were to add 120.32.111.01 to the RDP firewall for a customer or a system administrator, then you may need to add another rule for a different IP address.
Adding Your IP in Plesk
Step 1: Log in to Plesk
First, we need to make sure we know how to get to that Plesk login page. By default, the Plesk login page is https://<YourServerIP>:8443. For example, https://127.0.0.1:8443
We should arrive at a page with this in the center. Go ahead and type in Admin for the username and your password for Plesk. Usually, that password is set up by our team and is the default Server Administrator Password. Sometimes the username is Administrator, depending on a few variables. But one of the two usernames should be fine.
Step 2: Tools & Settings
The first thing we need to do after we log into Plesk through the previous page is to navigate to the Firewall Rules. Go ahead and click on Tools & Settings. It will be located in the right sidebar near the bottom as shown below.
Step 3: Firewall
Once we pull up Tools & Settings go ahead and click on our destination, Firewall. You will find that option under the Security section. It will be the second option, just under Security Policy.
Step 4: Firewall Rules
After we are in the Firewall management, go ahead and click on Firewall Rules. This is where we will add the rule to allow a certain IP address to gain RDP access.
Step 5: Add a Firewall Rule
Under Tools, after going into the Firewall Rules, we will see the option labeled Add Firewall Rule. Go ahead and click on that, bringing us to our next step.
Step 6: Add Detail the New Rule
This is the page that we see after clicking on Add Firewall Rule. It can seem to be complicated and intimidating for some beginner level System Administrators, but it is simple.
If you or your client are not sure what that IP address that needs RDP access is, Liquid Web has a great site to visit that will display your IP address.
Once you enter the IP address into the text box under Remote addresses, you do need to click the ADD button before clicking on OK.
As mentioned above, after clicking the ADD button while the IP address is entered into the Add an IP address or a network text box, it will be placed into the left text box. After that step, you will then be able to click OK to apply this rule to the firewall for the server.
Step 7: Connect to RDP
The individual at that IP address can now access the server via RDP. If you would like to review an article explaining how to use Remote Desktop Connection, or if you need further assistance, you can locate more info at our internal help center after logging into your Liquid Web account.
Congratulations! You now know how to add an IP address to an RDP rule that will allow a user to connect if the RDP is scoped off to the public. This can be done many times. Although Plesk does not allow you to edit the rule, you will have to create a new one each time. But this shouldn’t cause any issues. Also, keep in mind that this method can be used for any port, including MySQL and MSSQL.
The Most Helpful Humans In Hosting™
We pride ourselves on being The Most Helpful Humans In Hosting™! Our support staff is always available to assist with any Dedicated, Cloud, or VPS server issues 24 hours a day, 7 days a week 365 days a year.
We are available, via our ticketing systems at firstname.lastname@example.org, by phone (at 800-580-4986) or via a LiveChat for whatever method you prefer. We work hard for you so you can relax.