Simple and Load Balanced Host Records

Simple Host Records

To add a simple host record for each WAN link, a consistent naming scheme is recommended.  This will be useful to quickly identify which Internet providers a DNS record belongs to. Using the above chart (under Have Your Mappings Handy), we have all the information we need to add a Simple Host Record for www for each of the WAN links.  The information that is required includes the external IP address for each service and the WAN IP for each WAN link.   Valid hostname rules apply in this section meaning only alphanumeric characters and hyphens (“-”) are allowed. Each Host Name entry also must be unique for the entire zone.

1. Click the Add Host button under Simple Host Records.
2. Fill out the Host Name for the www record for the first WAN link, www-wan1. Substitute “wan1″ to follow your naming scheme.
3. In the IP Address or Hostname textbox enter the IP address found in the mapping spreadsheet for www.test.com WAN1. In the example 172.20.1.61.
4. Enter the recommended default TTL of 30 seconds in the Time To Live textbox.
5. Click Add Host and repeat steps 1 – 4 for WAN2.
6. Click the Activate button found at the top or bottom of the page.

Notice that “test.com” is not included in the Host Name field and the trailing “.” at the end of the record which signifies the root of the DNS naming structure. If this isn’t added it is assumed that the domain name for the zone is appended to the hostname. So www-wan1 becomes www-wan1.test.com. All Host Names configured in Authoritative DNS will usually be a single label, in other words, no “dots”.

Currently the domain configuration does not do a whole lot. It is unlikely that www-wan1 or www-wan2 are actual records for your domain. What we really want is a record that maps www.test.com to IP addresses on each WAN. This will be covered later in the next section.

If any additional non load balanced simple host records need to be added, this page is where you do so.

Adding Load Balanced Records

Once the Simple Host Records are completed for www for each of the WAN links, a Load Balanced record can be defined.

1. Under Load Balanced Host Records click the Add Host button.
2. Fill in the Host Name field with www which is our target hostname.
3. Click in the Canonicals (Name/IP) field, and you will see a drop down menu that includes all of the available Simple Host Records available for load balancing.
4. To select the Simple Host Record to load balance, you can either click on the hostname or just begin typing the first couple letters of the hostname and auto-complete will assist you in narrowing down which record to include.
5. The recommended default TTL is 30 seconds, enter this into the Time To Live text field.
6. Click the Activate button located at the top or bottom of the page.

Notice how both www-wan1 and www-wan2 are included in the Canonicals (Name/IP) column. A person trying to get to www.test.com will resolve two IP addresses: 172.20.1.61 and 10.50.0.21. These IP Addresses are handed out in round robin fashion so the load will be distributed across both WAN links.

Redundancy Only

For the next record, ftp.test.com, it has been decided that the primary line is WAN2; WAN1 should only be used if WAN2 is unavailable. To accomplish this follow the steps above in the Simple Host Records and Load Balancing Records sections. Afterwards the configuration should look like this.

Once an FTP record has been added for each WAN link, the next step is to configure the Ecessa device to use those records in a 'Redundancy Only' setup with WAN2 as the primary link.  In order to accomplish this there are two steps;  first, is the 'Redundancy Only' checkbox and second is the ordering in the Canonicals (Name/IP) field.

The first step is checking the ‘Redundancy Only’ checkbox. When Redundancy Only is checked the first highlighted entry in the Canonicals (Name/IP) field will be handed out. All other highlighted entries will be given out when the first highlighted entry is unavailable. In this example ftp-wan1 (172.20.1.61) is given out. From the requirements mentioned earlier, WAN2 (ftp-wan2) should be the primary.

To accomplish this click on the entry # next to the Simple Host Record that needs to be adjusted. An input box will appear below the cursor that allows you to adjust the entry to be moved.

Click the UP button to move entry # 4 up one row. This will position ftp-wan2 above ftp-wan1. Once the Simple Host Record is in the proper order, click the X button to close the update box. Now click on the Update Canonicals button under Load Balanced Host Records. Notice that the Canonicals (Name/IP) column of Load Balanced Host Records has been updated to reflect the ordering of the Simple Host Records. Finally, click the Activate button at the top or bottom of the page. The results should look like this.