lstf

lstf

lstf prints host flows (aggregated network connection flows to the same source or destination ports) by Linux netlink and enables you to simply grasp the network relationship between localhost and other hosts.

friend: yuuki/lsconntrack

Features

• Distinction of active open and passive open
• Print also the number of connections of each flows (the absolute values are meaningless)
• Go portability
• JSON support
• TCP support only

Installation

Download binary from GitHub Releases

https://github.com/yuuki/lstf/releases

How to use

HTTP requests --> Web:80 --> MySQL:3306

$ lstf -n
Local Address:Port   <-->   Peer Address:Port     Connections
10.0.1.9:many        -->    10.0.1.10:3306        22
10.0.1.9:many        -->    10.0.1.11:3306        14
10.0.2.10:22         <--    192.168.10.10:many    1
10.0.1.9:80          <--    10.0.2.13:many        120
10.0.1.9:80          <--    10.0.2.14:many        202

• --> indicates active open
• <-- indicates passive open

Sort flows by the number of connection.

$ lstf -n | sort -nrk4

JSON format

$ lstf --json | jq -r -M '.'
[
  {
    "direction": "active",
    "local": {
      "name"| "app01.local",
      "addr": "10.0.1.9",
      "port": "many"
    },
    "peer": {
      "name"| "db01.local",
      "addr": "10.0.100.1",
      "port": "3306"
    },
    "connections": 20
  },
  {
    "direction": "passive",
    "local": {
      "name"| "app01.local",
      "addr": "10.0.1.9",
      "port": "80"
    },
    "peer": {
      "name"| "web01.local",
      "addr": "10.0.200.1",
      "port": "many"
    },
    "connections": 27
  },
  ...
]

License

MIT

Author

yuuki