(31.12.2020, 12:14)admin Wrote: This depends on what kind of router you have and how easy it is to get information from it. Mikrotik is fully supported, Unify should also be possible via HTTP API. If you want to do presence detection this way you need ARP table instead of DHCP.

(31.12.2020, 13:09)admin Wrote: This has to be done on your router. See if you can enable a static DHCP entry for a certain MAC.

(31.12.2020, 13:09)admin Wrote: This has to be done on your router. See if you can enable a static DHCP entry for a certain MAC.

(04.01.2021, 07:57)admin Wrote: You should save the device IP in storage and periodically run the scan via a scheduled scripts to check for IP changes. You should also set a lower value for socket.http.TIMEOUT because default is 60 seconds to speed up the script. Check if your device has a non-standard TCP port open so the scan more consistent, because many network devices can have port 80 open.

Here's a script that can quickly check if any of local IPs have port 80 open:

Code:

require('socket')
prefix = '192.168.1.' -- ip address prefix
rangemin, rangemax = 2, 254 -- min/max of the scan range
port = 80 -- TCP port to check

sockets = {}
ips = {}

-- create sockets and connect
for i = rangemin, rangemax do
  ip = prefix .. i
 
  sock = socket.tcp()
  sock:settimeout(0)
  sock:connect(ip, port)

  sockets[ #sockets + 1 ] = sock
  ips[ sock ] = ip
end

-- get a list of sockets that can be written to, this means that the connection is established
_, res, err = socket.select(nil, sockets, 1)

res = res or {}

-- log IPs of all sockets that accepted the connection
for _, sock in ipairs(sockets) do
  if res[ sock ] then
    ip = ips[ sock ]
    log(ip)
  end

  sock:close()
end

-- clean-up in case running as a resident script
sockets = nil
ips = nil

(04.01.2021, 07:57)admin Wrote: You should save the device IP in storage and periodically run the scan via a scheduled scripts to check for IP changes. You should also set a lower value for socket.http.TIMEOUT because default is 60 seconds to speed up the script. Check if your device has a non-standard TCP port open so the scan more consistent, because many network devices can have port 80 open.

Here's a script that can quickly check if any of local IPs have port 80 open:

Code:

require('socket')
prefix = '192.168.1.' -- ip address prefix
rangemin, rangemax = 2, 254 -- min/max of the scan range
port = 80 -- TCP port to check

sockets = {}
ips = {}

-- create sockets and connect
for i = rangemin, rangemax do
  ip = prefix .. i
 
  sock = socket.tcp()
  sock:settimeout(0)
  sock:connect(ip, port)

  sockets[ #sockets + 1 ] = sock
  ips[ sock ] = ip
end

-- get a list of sockets that can be written to, this means that the connection is established
_, res, err = socket.select(nil, sockets, 1)

res = res or {}

-- log IPs of all sockets that accepted the connection
for _, sock in ipairs(sockets) do
  if res[ sock ] then
    ip = ips[ sock ]
    log(ip)
  end

  sock:close()
end

-- clean-up in case running as a resident script
sockets = nil
ips = nil