You work outside of the main office and use a remote connection to access where the GeoExpress license server lives. Everyone in the office can get a floating license for GeoExpress, but your computer can't even see the server. What is happening?
Typically GeoExpress requires a constant "heartbeat" between the client software and the license server. These heartbeats stay connected to each other by sending packets of information back and forth. When network traffic travels along a remote connection sometimes it breaks up (fragments) the pieces of information that it sends back and forth. For some network situations packet fragmentation is unavoidable with the default setting. This setting can be modified by changing the size of the Maximum Transmission Unit (MTU) on your network. Setting the MTU on your server to the maximum size allowable on your network permits packets within that size to travel without fragmenting. This improves the license connection and allows GeoExpress to function in remote environments.
Open a command prompt as an administrator on your license server computer
Enter the following commands one at a time:
- interface ipv4
- show subinterfaces
This will present a list of network interfaces running on the computer. The correct option to choose depends on your environment and how you are connected to the network. You need to identify which interface the license server is using to connect to the network. Once you know which option to choose enter the following command:
- set subinterface "YOURSUBINTERFACENAMEHERE" mtu=1359 store=persistent
This setting will set the MTU to 1359 (a common network restriction size) and save it as a permanent selection on the YOURSUBINTERFACENAMEHERE interface. Now you should be able to connect to the GeoExpress license server with ease.
Why does this fix the problem? Information travels across networks in the form of packets. The license server doesn't care what size of packet is being sent, and GeoExpress doesn't care what size of packet it receives. However GeoExpress is not able to accept fragmented packets.
Let's personify this. Imagine that the license server is a busy executive. She has a big pile of paper (the floating license information) that she wants to send out to their client GeoExpress. She doesn't care how it gets there so she gives it to the building manager (the computer where the license server is installed). She tells the building manager to ship these papers to GeoExpress.
The building manager takes this stack of papers, organizes it into packets of 1500, and puts a staple in each corner. They put each packet of paper next to the door for the delivery service to pick up. In this analogy the delivery service is the network.
The delivery drivers don't like this because the packets are too heavy. The drivers see the stack of paper and say, "I can't do this!" because their trucks have a weight limit of 1359 papers. So they rip the staple out of each packet and break each one up into sizes that the truck can carry.
When those papers get to the GeoExpress client they arrive in a big jumble instead of neatly stacked like it expected to see - so the client doesn't know what to do with them. It can't piece them back together again and tosses them in the junk mail bin. The client and the executive never get to communicate with each other because the mail never gets through.
When you set the MTU on the license server computer you are telling the building manager "I know you can make paper packets that are 1500 pages, but I want you to only make them 1359 pages instead" which it agrees to. Then it starts sending packets of 1359 pages. When these packets get to the delivery driver they go through just fine because they are less than its weight limit. This means that when the packets of paper arrive at GeoExpress they are still organized in an easily understandable way.
This article was last updated or verified on 28 Oct 2016