Jumbo Frames refer to Ethernet frames that carry a payload of up to 9000 bytes, instead of the standard 1500 bytes. These frames can increase network throughput and reduce CPU utilization.
Here’s how you can test Jumbo Frames on different operating systems:
Windows
In Windows, you can use the `ping` command with the `-f` (don’t fragment) and `-l` (size) options. Note that the MTU value is inclusive of headers which take 28 bytes, so use a size of 8972 bytes to test a Jumbo Frame of 9000 bytes. This is assuming your network adapters and switch are configured to handle Jumbo Frames.
ping destination_IP -f -l 8972
MacOS / Linux
On MacOS and Linux, the `ping` command works a little differently. The `-s` option is used to specify the size. The `-M do` option ensures that packets are not fragmented.
ping -s 8972 -M do destination_IP
Make sure to replace `destination_IP` with the IP address of the machine you are testing connectivity with. Also, the other machine must also be configured to handle Jumbo Frames.
Do remember that for Jumbo Frames to work, all devices in the network path must support them. This includes the network interface cards of the source and destination machines, switches, routers, and any other network devices between them.
If you’re unable to ping using the above commands, you might need to adjust the MTU setting on your network adapter to handle Jumbo Frames (usually setting it to 9000 should work). Be aware that incorrectly setting the MTU can cause network issues, so proceed with caution and only if you’re confident in what you’re doing.
Cisco
To test the Jumbo Frames on a Cisco device, you can use the `ping` command with the `df-bit` (do not fragment) and `size` options. You would have to be in the privileged exec mode (enable mode) to do this.
Here’s an example:
Router# ping ip destination_IP size 8972 df-bit
OR
Router# ping Protocol [ip]: Target IP address: destination_IP Repeat count [5]: Datagram size [100]: 8972 Timeout in seconds [2]: Extended commands [n]: y Source address or interface: Type of service [0]: Set DF bit in IP header? [no]: yes Validate reply data? [no]: Data pattern [0xABCD]: Loose, Strict, Record, Timestamp, Verbose[none]: Sweep range of sizes [n]: Type escape sequence to abort.
Just as in the previous examples, replace `destination_IP` with the IP address of the machine you are testing connectivity with.
Again, remember that all the devices in the network path must support and be configured for Jumbo Frames for them to work properly. Also, this assumes that your router is configured to support Jumbo Frames (i.e., the MTU on the router interfaces has been set to a size greater than the default, usually 9000 for Jumbo Frames).
As always, ensure you know the impact of changing these settings before doing so, as incorrectly setting the MTU or enabling Jumbo Frames without full network support can cause network issues.