sys-cmd fping

sys-cmd fping sends an ICMP echo request to more than one target at the same time from the route table selected in WEB-CLI and reports on a separate line whether each target responds. It is used to probe the servers in a backend group or the addresses in a subnet in a single command.

Command Summary

TR7 WEB-CLI · sys-cmd fping

# type fping and press Tab: a free parameter

admin@TR7LBWAF01> sys-cmd fping

<fping-parameter-1>

 

admin@TR7LBWAF01> sys-cmd fping <parameters> <target-1> <target-2> …

admin@TR7LBWAF01>  

Everything written after the word fping is passed to the tool as it is. There is no mandatory field; the targets are written separated by spaces or as a range with -g.

How It Works

Subject	Behavior
Context	The packets are sent from within the selected v-device and route table.
Duration	It closes by itself when all the targets have been probed.
Stopping	Ctrl+C stops the tool.
Pipe	The output can be filtered or counted with |, or written to a file with to-file.
Recording	Every run is written to the user logs.

Frequently Used Parameters

Parameter	What it does	What is written after it
-a	Lists only the targets that respond	—
-u	Lists only the targets that do not respond	—
-g	Produces the target list from a subnet or from start–end addresses	10.20.0.0/24 or 10.20.0.10 10.20.0.50
-c	Determines the number of packets to be sent to each target; at the end it writes a loss and latency summary per target	A number (e.g. 3)
-e	Writes the latency next to the targets that respond	—
-q	Does not write the packet-by-packet lines	—
-r	Determines how many times a target that does not respond will be retried	A number
-t	Determines the waiting time for the first response	Milliseconds

The table summarizes frequently used parameters; the full list and behavior depend on the version of the tool on the device.

Examples

TR7 WEB-CLI · A) Three backends, with the response time

admin@TR7LBWAF01> sys-cmd fping -e 10.20.0.15 10.20.0.16 10.20.0.17

admin@TR7LBWAF01>  

TR7 WEB-CLI · B) Three packets to each backend, a loss summary

admin@TR7LBWAF01> sys-cmd fping -c 3 -q 10.20.0.15 10.20.0.16 10.20.0.17

admin@TR7LBWAF01>  

TR7 WEB-CLI · C) The addresses that respond in a subnet

admin@TR7LBWAF01> sys-cmd fping -a -g 10.20.0.0/24

admin@TR7LBWAF01>  

TR7 WEB-CLI · D) The number of addresses in the range that do not respond

admin@TR7LBWAF01> sys-cmd fping -u -r 1 -g 10.20.0.10 10.20.0.50 | wc -l

admin@TR7LBWAF01>  

Things to Know

• A wide range. While a large subnet is being scanned with -g, a large number of packets is sent to the network; on a production network it is started with a narrow range.
• Not every address that does not respond is down. The service of a target that blocks ICMP may be working; critical backends are verified at the port level with nmap.
• For a single target ping gives more detailed output.