| Release | Status |
|:---:|---|
| Crates.io | 
```bash $ rnp 8.8.8.8:443 -r -l rnp - r12f (r12f.com, github.com/r12f) - A simple layer 4 ping tool for cloud.
Start testing TCP 8.8.8.8:443: Reaching TCP 8.8.8.8:443 from 192.168.50.153:8940 succeeded: RTT=12.95ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:8941 succeeded: RTT=11.24ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:8942 succeeded: RTT=10.96ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:8943 succeeded: RTT=12.43ms
=== TCP connect statistics for 8.8.8.8:443 === - Packets: Sent = 4, Received = 4, Lost = 0 (0.00% loss). - Round trip time: Minimum = 10.96ms, Maximum = 12.95ms, Average = 11.90ms.
=== Ping result scatter map ===
Src | Results
Port | ("1" = Ok, "0" = Fail, "-" = Not Tested) --------+-0---4-5---9-0---4-5---9------------------- 8940 | 1111- ----- ----- -----
=== Latency scatter map (in milliseconds) ===
Src Port | Results ("X" = Fail, "-" = Not Tested) -----------+----0------1------2------3------4------5------6------7------8------9--- 8940 | 12.95 11.24 10.96 12.43 - - - - - - ```
Ping is one of the most frequently used tool for testing network reachability. And yet, we have another one here... So why?
Despite there are numerous ping tools in the market, I wrote RNP for some specific reasons: * Wide platform support, so we can run it everywhere. * Wide platform support: Windows/Linux, x86/amd64/arm64. * Wide machine environment support: Minimum dependencies, such as runtimes like JRE/CLR. * Be cloud-friendly: * Support scanning all network paths. * Nowadays, services and network data paths are mostly redundant. Technologies like load balancer and [ECMP] are widely used in cloud and modern data center. * Because of this, if a service, or a network link is having trouble, we will see intermediate packet drop/latency, instead of seeing full connectivity drop. Hence, we need a tool to help us scan all possible network paths and find out the bad links. * Minimize port usage (Friendly to SNAT). * High port usage can cause SNAT port allocation failures, which result in false negatives. And it can be easily triggered by scanning. * This is a very common error in all clouds, such as AWS and Azure. * Avoid unstable measurements when possible. * Easy to use. * ...
To help us achieve the things above, we are implementing our ping in a very specific way. * TCP connect as ping. Focus on network reachability. * Why not ICMP ping? 1. Unlike TCP, ICMP is lacking of variant, which makes it bad for scanning all possible network paths. 2. ICMP is banned in many machines and network for security reasons, so ICMP timeout doesn't really mean it is timeout. * Why not UDP ping? 1. UDP is connectionless, so there is no so-called UDP ping. 2. Existing UDP ping tool uses ICMP unreachable message for detecting if a UDP port is reachable or not, which causes 2 problems: 1. Implementation usually involves using raw socket, which is really bad for performance, especially in cloud, where the network load could be high. 2. Same as ICMP ping. ICMP can be banned, hence UDP ping works doesn't really mean UDP port is open. (And one of the reasons that people ban ICMP is to avoid this UDP port scan.) * Parallel pings for spray all possible network paths: * We rotate the source port to make each ping having different tuples to allow them going through different network path. * Parallel pings with configurable ping intervals can dramatically increase the scanning speed. * RST instead of FIN by default. Minimize port usage. * Most of the tcp connect tools follows the regular way to disconnect the TCP connection - the 4-way handshake with FIN packet. This is great for servers, but not for testing. * The regular disconnect leaves the ports in TIME_WAIT state, and the cloud load balancers have to keep tracking these SNAT ports as well. It can easily cause SNAT port allocation error, which will make the network for your service even worse. You definitely don't want to see this. * Use [Rust] as the programming language: * Rust is a system language with very light-weighted and GC-free runtime, which means no more random lags during our measurements, such as stop-the-world stages in GC. * Rust has wide range of platform support and produces almost self-contained native binaries, so we can simply copy and run. * Rust is as fast as C, while also has great support for modern age asynchronous programming. Gems like go-like mpsc channel, async/await, you can find them all in Rust. * ... * Friendly result output: * Besides outputting just like ping, we also provided other ways to show the results, such as very compacted scatter map. * We also support outputting the result into CSV/JSON/Text files for later analysis or scripting.
Some hard decisions:
* DNS name resolution is intentionally not supported. Using IP address is enforced when using our ping.
* This is because DNS can return different result based on geo-location. This misleads people a lot when collaborating on network issues, because it might end up with different people debugging different issues without even knowing it for long time.
* To get IP from DNS, we can run nslookup <domain-name>.
Ok, let's check some real cases to get started!
The simplest case - regular TCP connect test. Works just like ping. ```bash rnp 8.8.8.8:443 rnp - r12f (r12f.com, github.com/r12f) - A simple layer 4 ping tool for cloud.
Start testing TCP 8.8.8.8:443: Reaching TCP 8.8.8.8:443 from 192.168.50.153:10401 succeeded: RTT=11.17ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:10402 succeeded: RTT=13.36ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:10403 succeeded: RTT=14.27ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:10404 succeeded: RTT=12.39ms
=== TCP connect statistics for 8.8.8.8:443 === - Packets: Sent = 4, Received = 4, Lost = 0 (0.00% loss). - Round trip time: Minimum = 11.17ms, Maximum = 14.27ms, Average = 12.80ms. ```
Now let's make our ping faster by adding -p 10 to spawn 10 workers and -i 0 to remove the intervals we wait between each ping, then run 100 pings. And to avoid abusing our console, we disable the regular output (-q), enable the result scatter map (-r) and log the details to a json file for later use (--log-json log.json).
```bash
$ rnp.exe 8.8.8.8:443 -p 10 -i 0 -n 100 -q -r --log-json log.json
rnp - r12f (r12f.com, github.com/r12f) - A simple layer 4 ping tool for cloud.
Start testing TCP 8.8.8.8:443: 97 pings finished. === TCP connect statistics for 8.8.8.8:443 === - Packets: Sent = 100, Received = 96, Lost = 4 (4.00% loss). - Round trip time: Minimum = 10.91ms, Maximum = 999.43ms, Average = 55.16ms.
=== Ping result scatter map ===
Src | Results
Port | ("1" = Ok, "0" = Fail, "-" = Not Tested) --------+-0---4-5---9-0---4-5---9------------------- 18180 | ----- ----1 11111 11111 18200 | 11111 11111 11111 11111 18220 | 11111 11111 11111 11111 18240 | 11111 11111 11111 11111 18260 | 11111 11111 11111 11111 18280 | 10000 1111- ----- ----- ```
We will see the test will complete almost immediately, and the details will be logged into the json file:
json
[
{"utcTime":"2021-07-09T04:54:50.465178Z","protocol":"TCP","workerId":4,"targetIP":"8.8.8.8","targetPort":"443","sourceIP":"192.168.50.153","sourcePort":"18285","roundTripTimeInMs":17.14,"error":""},
{"utcTime":"2021-07-09T04:54:50.465430300Z","protocol":"TCP","workerId":8,"targetIP":"8.8.8.8","targetPort":"443","sourceIP":"192.168.50.153","sourcePort":"18288","roundTripTimeInMs":23.25,"error":""},
{"utcTime":"2021-07-09T04:54:50.458698800Z","protocol":"TCP","workerId":6,"targetIP":"8.8.8.8","targetPort":"443","sourceIP":"0.0.0.0","sourcePort":"18282","roundTripTimeInMs":998.91,"error":"timed out"},
]
And now, we can see our ping failed on port 19653, then we can start a continuous ping to rerun the bad ports. And we can see a fairly high failure rate on this port as below. ```bash $ rnp.exe 8.8.8.8:443 --src-port 18282 -t rnp - r12f (r12f.com, github.com/r12f) - A simple layer 4 ping tool for cloud.
Start testing TCP 8.8.8.8:443: Reaching TCP 8.8.8.8:443 from 192.168.50.153:18282 succeeded: RTT=11.65ms Reaching TCP 8.8.8.8:443 from 0.0.0.0:18282 failed: Timed out, RTT = 999.24ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18282 succeeded: RTT=12.24ms ..... ```
Also, we can easily try all failure ports again and see how they look like. Here is an example using powershell, and on non-windows platform, we can easily do the same thing with tools like [jq]: ```bash
$ $ports = (gc .\log.json | ConvertFrom-Json | % { $_ } | ? { $.error -eq "timed out" } | % { $.sourcePort }) -join "," $ $ports 18282,18281,18284,18283
$ rnp.exe 8.8.8.8:443 --src-port $ports -t rnp - r12f (r12f.com, github.com/r12f) - A simple layer 4 ping tool for cloud.
Start testing TCP 8.8.8.8:443: Reaching TCP 8.8.8.8:443 from 192.168.50.153:18284 succeeded: RTT=11.24ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18283 succeeded: RTT=11.15ms Reaching TCP 8.8.8.8:443 from 0.0.0.0:18282 failed: Timed out, RTT = 999.14ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18281 succeeded: RTT=11.53ms Reaching TCP 8.8.8.8:443 from 0.0.0.0:18284 failed: Timed out, RTT = 999.50ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18283 succeeded: RTT=11.88ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18282 succeeded: RTT=10.90ms Reaching TCP 8.8.8.8:443 from 0.0.0.0:18281 failed: Timed out, RTT = 999.38ms Reaching TCP 8.8.8.8:443 from 192.168.50.153:18284 succeeded: RTT=14.40ms ..... ```
And rnp will start to rotate the ping within all the specified source ports for testing.
To see more on this tool, we can try --help option.
```bash
$ rnp.exe --help
rnp 0.1.0
r12f (r12f.com, github.com/r12f)
A simple layer 4 ping tool for cloud.
USAGE:
rnp.exe [FLAGS] [OPTIONS]
FLAGS: -h, --help Prints help information -q, --no-console-log Don't log each ping result to console. Summary and other things will still be written to console. -t Ping until stopped. -l, --show-latency-scatter Show latency (round trip time) scatter map after ping is done. -r, --show-result-scatter Show ping result scatter map after ping is done. --use-fin Use regular TCP disconnect (w/ FIN) instead of RST. -V, --version Prints version information
OPTIONS:
--log-csv
ARGS:
Thanks a lot in being interested in this project and all contributions are welcomed!
To contribute to the project, please feel free to open issues and discuss. Then submit a pull request for review and merge into main branch.
Just like the rest of Rust project, simply use cargo to build it.
bash
$ cargo build
To build release version:
bash
$ cargo build --release
To build other targets, such as ARM64 on windows, we can use --target to specify the target (of course, in this specific case, we need to install the msvc ARM64 toolchain from visual studio).
bash
$ cargo build --target=aarch64-pc-windows-msvc --release
Apache-2.0: https://www.apache.org/licenses/LICENSE-2.0