Java CLI to test TCP reachability from local interfaces to a set of hosts over a range of ports in an automatic and time efficient manner. For firewall rule testing etc.
Run on a given host, this Java executable .jar identifies the local host name, and each of its the available network interfaces. Provided with a list of hosts to connect to, and a set or range of ports, it will attempt to connect with TCP from each local interface to each combination of external host and port in parallel a number of times. It collates, agregates and reports on connection:
- success
- timeout
- refused
- unreachable
and timings for each. In this way each potential route from a local interface to a set of external hosts, say through a firewall, can be confirmed or diagnosed in as short a time as possible.
Output is formated for a spreadsheet as CSV by default, but can be JSON and also POSTed to an object DB such as ElasticSearch.
Connect-O-Matic is coded to be packaged as an executable .jar and run from the CLI. It's written for Java 8 and with Maven packaging (because I find Maven to be easier than gradle). Download the source and, to build and get help:
technosf@github:connectomatic~$ mvn package
technosf@github:connectomatic~$ java -jar target/connectomatic-1.2.0.jar -?
Connect-O-Matic Version: 1.2.0
Copyright 2023 technosf [http://github.com/technosf]
Help:
-i IPv - 4 and/or 6, defaults to 4 and 6 if absent
-p Port numbers, at least one required, can be a hyphenated range
-h Hosts as hostnames, IPv4 or IPv6 addresses, at least one required
-a Attempts to connect, defaults to 5, but can be 1-255
-l Local addresses in the host set should be tested and not ignored
-j Produce JSON output instead of CSV
-u URI, POST JSON results to the provided URI
-q Quiet mode, outputs result only, without preamble or summary
-d Dry-run, run through resolving the targets without attempting any connects
-? Produces this message
Examples:
java -jar connectomatic-*.*.*.jar -p 22 80 -h github.com www.github.com
java -jar connectomatic-*.*.*.jar -p 80-90 -h github.com www.github.com localhost -l
java -jar connectomatic-*.*.*.jar -i 4,6 -p 22,80-90 -h github.com,www.github.com
java -jar connectomatic-*.*.*.jar -j -i 4,6 -p 22,80-90 -h github.com,www.github.com
java -jar connectomatic-*.*.*.jar -a 1 -u http://myobjectdb/index -i 6 -p 22,80-90 -h github.com,www.github.com
Output by default is .csv with header - JSON via a switch.
Fields are:
• IPv
• Local Interface
• Remote Address
• Remote Hostname
• Remote Port
• Connections
• Connection μs Avg
• Connection μs Min
• Connection μs Max
• Timeouts
• Timeout μs Avg
• Refused connection count
• Unreachable network countTo identify local interfaces, invoke with no arguments:
technosf@github:connectomatic~$ java -jar target/connectomatic-1.2.0.jar
Connect-O-Matic Version: 1.2.0
Local Interfaces: 2020-08-07T14:26:38.114617
Interfaces:
lo
wlp1s1 DE:AD:BE:ED:01:23A
Loopback Addresses:
IPv4
localhost 127.0.0.1
IPv6
ip6-localhost 0:0:0:0:0:0:0:1%lo
LinkLocal Addresses IPv6:
fe80:0:0:::1a921%wlp1s1 fe80:0:0:::1a921%wlp1s1
IPv4 Addresses:
192.168.0.99 192.168.0.99To test an example connection:
technosf@github:connectomatic~$ java -jar connectomatic-1.2.0.jar -h github.com -p 22 80 -i 4
Connect-O-Matic Version: 1.2.0
Summary Connects: 10 Timeouts: 0 Refused: 0 Unreachable: 0
"IPv","Interface","Remote Address","Remote Hostname","Remote Port","Connections","Connection μs Avg","Connection μs Min","Connection μs Max","Timeouts","Timeout μs Avg","Refused","Unreachable"
4,192.168.13.48,140.82.114.4,github.com,22,5,320.65453338623047,65.01171112060547,1101.0047607421875,0,0.0,0,0
4,192.168.13.48,140.82.114.4,github.com,80,5,86.8220932006836,63.963134765625,173.01504516601562,0,0.0,0,0
Output is in CSV format, replete with column header: It can be copied and paste/special directly into LibreOffice Calc as csv or saved as a .csv and opened with a spreadsheet.
Coded as Java 8 rather than 14+ to maximise build/use options. Hence no Java Record types which would be the main benefit in the code.
Added switches to:
- test connections to/from local interfaces if they are included in the hosts parameter. Otherwise they are now ignored, allowing the same host set to be used accross hosts without redundant results in the output.
- set the number of connection attemps - defaults to 5.
- output results as JSON instead of CSV.
- POST results to an URI as a JSON payload, i.e. to get the results into an object DB.
- quiet version and summary output.
- dry-run, resolving endpoints but not testing/connecting to them.
Support for port ranges in the input parameters. If a consecutive range of ports is to be tested, rather than having to list every port individually, they can be specified with a range: startport-endport.
- Added summary of connection tries to the result header.
- Added min and max connection times to .CSV
- Corrected an error in the connection time math.
Finessed Initial Release
Basic discovery of local interfaces and connection testing from a given local interface to remote host and port, providing connection results and average connection timings in .csv format.
Initial Release
Basic discovery of local interfaces and connection testing from a given local interface to remote host and port, providing connection results and average connection timings.
Connect-O-Matic - IP network connection tester
Copyright 2023 technosf [http://github.com/technosf]
This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.
https://www.gnu.org/licenses/gpl-3.0.en.html
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.