Package fragmentation
Fragmentation is the process of dividing traffic packets transmitted over the network into parts (fragments), each of which does not exceed the MTU size of the route. Kaspersky SD-WAN checks whether fragmentation of traffic packets is supported on each CPE device.
The MTU size determines the maximum amount of data that can be transmitted over the network in a single traffic packet. Fragmentation problems within the SD-WAN network can cause data transfer to become unstable or to stop completely.
A packet fragmentation test is started automatically. When enabled, each CPE device sends two ICMP requests from all WAN ports to IP addresses that you specified when creating SD-WAN interfaces or in the SD-WAN Controller configuration file when deploying the solution.
The ICMP requests have a packet size of 1,600 bytes. If at least one of these requests receives a response, a conclusion is made that the CPE device supports packet fragmentation.
A packet fragmentation test on a CPE device may yield one of the following results:
- Unsupported means the device cannot transmit fragmented packets.
- Unknown means the software installed on the CPE device does not support testing packet fragmentation.
- Supported means the device can transmit fragmented packets.
The fragmentation test result is displayed in the Fragmentation column of the overall table of links in the Tunnels section, as well as in the column of the same name in the link table in the configuration on the CPE device, on the Tunnels tab. Only links built using the particular CPE device are displayed in the configuration of that device.
