SNMP protocol in Logic Machine

[admin]

You can also try adding ups1:close() to the end of each resident script.

[Carlos Padilla]

Thanks for your collaboration, with the last thing that I indicated, the problem was solved and I no longer drop the connection.

[DGrandes]

Hi,

I have a problem with snmp conection.

I have this script:

Code:

require "snmp"

ups1, err = snmp.open{
 version = snmp.SNMPv2,
 community = "public",
 port = 161,
 peer = "192.168.2.201",
}

assert(ups1, err)

vbind, err = ups1:get(".1.3.6.1.4.1.24681.1.2.1.0") --Uso de la CP
grp.update('38/2/1', vbind.value)
vbind, err = ups1:get(".1.3.6.1.4.1.24681.1.2.2.0") --Memoria total del sistema
grp.update('38/2/2', vbind.value)
vbind, err = ups1:get(".1.3.6.1.4.1.24681.1.2.3.0") --Memoria libre
grp.update('38/2/3', vbind.value)
vbind, err = ups1:get(".1.3.6.1.4.1.24681.1.2.4.0") --Tiempo en linea
grp.update('38/2/4', vbind.value)

ups1.close()

When I play resident script (5s) it work fine, but later, i get the following error:

Resident script:18: netsnmp: Unknown host (192.168.2.201)
stack traceback:
[C]: in function 'assert'

Can you help me?

Thanks

[DGrandes]

Hi.

I have been loging data and I have created a script that restarts the snmp script when it fails, and it works again.
I have verified that the snmp script fails exactly every 2.5h

Any idea?

[admin]

Your script is incorrect, it must have ups1:close() instead of ups1.close()
This caused open sessions not to close properly so the script hits open socket limit after some time.

[DGrandes]

Your script is incorrect, it must have ups1:close() instead of ups1.close()
This caused open sessions not to close properly so the script hits open socket limit after some time.

I had not seen it....

Thanks!!!

[DGrandes]

Hi, my script still doesn´t work (only sometimes). I get the same error: 

Resident script:45: netsnmp: Unknown host ("MyIP")
stack traceback:
 [C]: in function 'assert'

Code:

require "snmp"

local IP_NAS = "MyIP"
local OID_NAS = {
 {'38/2/1',".1.3.6.1.4.1.24681.1.2.1.0"}, --Uso de la CPU
 {'38/2/2',".1.3.6.1.4.1.24681.1.2.2.0"}, --Memoria total del sistema
 {'38/2/3',".1.3.6.1.4.1.24681.1.2.3.0"}, --Memoria libre
 {'38/2/4',".1.3.6.1.4.1.24681.1.2.4.0"}, --Tiempo en linea
}

ups1, err = snmp.open{
 version = snmp.SNMPv2,
 community = "public",
 port = 161,
 peer = IP_NAS,
}

assert(ups1, err)

for i = 1, #OID_NAS, 1 do
    vbind, err = ups1:get(OID_NAS[i][2])
    grp.update(OID_NAS[i][1], vbind.value)  
end

ups1:close()

Any idea?

Thanks

[admin]

Change MyIP to real IP address of your SNMP device

[DGrandes]

MyIP =192.168.2.201

[admin]

Post full listing of your script. The error that you have is at line 45 whereas the code you posted has only 25 lines.

[DGrandes]

Sorry, here full script:

Code:

require "snmp"

--local mib,err = snmp.mib.load ('/home/ftp/snmp/....mib')
--[[
if not mib then
 log ('Fallo carga Mib: '..err)
end]]

local IP_NAS = "192.168.2.201"
local OID_NAS = {
 {'38/2/1',".1.3.6.1.4.1.24681.1.2.1.0"}, --Uso de la CPU
 {'38/2/2',".1.3.6.1.4.1.24681.1.2.2.0"}, --Memoria total del sistema
 {'38/2/3',".1.3.6.1.4.1.24681.1.2.3.0"}, --Memoria libre
 {'38/2/4',".1.3.6.1.4.1.24681.1.2.4.0"}, --Tiempo en linea
 {'38/2/5',".1.3.6.1.4.1.24681.1.2.11.1.3.1"}, --Temperatura HD 1
 {'38/2/6',".1.3.6.1.4.1.24681.1.2.11.1.3.2"}, --Temperatura HD 2
 {'38/2/7',".1.3.6.1.4.1.24681.1.2.11.1.3.3"}, --Temperatura HD 3
 {'38/2/8',".1.3.6.1.4.1.24681.1.2.11.1.3.4"}, --Temperatura HD 4
 {'38/2/9',".1.3.6.1.4.1.24681.1.2.11.1.4.1"}, --Estado del HD 1
 {'38/2/10',".1.3.6.1.4.1.24681.1.2.11.1.4.2"}, --Estado del HD 2
 {'38/2/11',".1.3.6.1.4.1.24681.1.2.11.1.4.3"}, --Estado del HD 3
 {'38/2/12',".1.3.6.1.4.1.24681.1.2.11.1.4.4"}, --Estado del HD 4
 {'38/2/13',".1.3.6.1.4.1.24681.1.2.11.1.6.1"}, --Capacidad Disco duro 1
 {'38/2/14',".1.3.6.1.4.1.24681.1.2.11.1.6.2"}, --Capacidad Disco duro 2
 {'38/2/15',".1.3.6.1.4.1.24681.1.2.11.1.6.3"}, --Capacidad Disco duro 3
 {'38/2/16',".1.3.6.1.4.1.24681.1.2.11.1.6.4"}, --Capacidad Disco duro 4
 {'38/2/17',".1.3.6.1.4.1.24681.1.2.11.1.7.1"}, --Smart Info HD 1
 {'38/2/18',".1.3.6.1.4.1.24681.1.2.11.1.7.2"}, --Smart Info HD 2
 {'38/2/19',".1.3.6.1.4.1.24681.1.2.11.1.7.3"}, --Smart Info HD 3
 {'38/2/20',".1.3.6.1.4.1.24681.1.2.11.1.7.4"}, --Smart Info HD 4
 {'38/2/21',".1.3.6.1.4.1.24681.1.2.13.0"}, --Hostname
 {'38/2/22',".1.3.6.1.4.1.24681.1.2.17.1.2.1"}, --Descripcion del Volumen
 {'38/2/23',".1.3.6.1.4.1.24681.1.2.17.1.4.1"}, --Capacidad total del volumen
 {'38/2/24',".1.3.6.1.4.1.24681.1.2.17.1.5.1"}, --Espacio Libre Volumen
 {'38/2/25',".1.3.6.1.4.1.24681.1.2.17.1.6"}, --Estado del volumen
}

ups1, err = snmp.open{
 version = snmp.SNMPv2,
 community = "public",
 port = 161,
 peer = IP_NAS,
}

assert(ups1, err)

for i = 1, #OID_NAS, 1 do
    vbind, err = ups1:get(OID_NAS[i][2])
    grp.update(OID_NAS[i][1], vbind.value)  
end

ups1:close()

[DGrandes]

Hi,

Here another error that give me many times:
From 17:30 to 8:35AM last time. Now works again.

Resident script:49: attempt to index global 'vbind' (a nil value)
stack traceback:

[admin]

This happens because there's no error check for get() calls.

Use this code:

Code:

for _, item in ipairs(OID_NAS) do
  vbind, err = ups1:get(item[2])
  if vbind then
    grp.update(item[1], vbind.value)  
  else
    alert('error reading from snmp: ' .. tostring(err))
  end
end

[DGrandes]

This happens because there's no error check for get() calls.

Use this code:

Code:

for _, item in ipairs(OID_NAS) do
 vbind, err = ups1:get(item[2])
 if vbind then
   grp.update(item[1], vbind.value)  
 else
   alert('error reading from snmp: ' .. tostring(err))
 end
end

Ok, I´ll try it.

Thanks!!

[Carlos Padilla]

Hello forum partners. Now I have two devices. The first is a projector which has an SNMP communication and I want to turn on and off, change the video input for which I have to write a value in the respective OIDs. I tested the projector both by writing and reading the SNMP variables by means of an SNMP management software and it works without any problem, but with the LM I have made a script by event to turn it on, but it does not work for me. On the other hand I have a team that uses SNMP Version 3 which replaces the community by user name, an authentication code, a privacy code and the protocol of these (MD5, SHA, DES, AES) which is not compatible with the current code, in addition to having some Tramps which I have to be aware of and I do not know how to do it, so if they have any way of doing it, it would be very helpful. I include the code I did to write about an SNMP OID, which does not work for me. Thank you and I am attentive to your comments.

Code:

val=event.getvalue()
--Abrir una sesión con snmp
require "snmp"

ups1, err = snmp.open{
  version = snmp.SNMPv1,
  community = "public",
  port = 161,
  peer = "192.168.0.243",
}
assert(ups1, err)

if value==true then

  vbind, err = ups1:set("1.3.6.1.4.1.1248.4.1.1.2.1.0", 1) 
 
else
vbind, err = ups1:set("1.3.6.1.4.1.1248.4.1.1.2.1.0", 0) 
 
   
end

ups1:close()

[admin]

See library documentation on how to correctly call set function: http://luasnmp.luaforge.net/snmp.html#snmp_set

I haven't tried using SNMPv3, but you can try this code:

Code:

ups1, err = snmp.open({
  port = 161,
  peer = "192.168.0.243",
  version = snmp.SNMPv3,
  user = "username",
  password = "123456",
})

SNMP traps are not supported at this moment.

[Carlos Padilla]

Hi Admin, thanks for replying. With the help of the library manual I understand the script a bit more, in addition to the version 3 SNMP, and then I will try to try the version with what the manual says. The problem I have is to write to an OID, I have already tried many things but it still does not work, I have even commented, tried several parts of the code but it still does not work. I put it together to see if I'm wrong about something. Thank you and I am attentive to your comments

Code:

val=event.getvalue()
--Abrir una sesión con snmp
require "snmp"
--value=1
ups1, err = snmp.open{
  version = snmp.SNMPv1,
  community = "public",
  port = 161,
  peer = "192.168.0.248",
}
assert(ups1, err)

vbOut, err = ups1:set("1.3.6.1.4.1.1248.4.1.1.2.1.0", 0)

--vlist = {
--{oid = "1.3.6.1.4.1.1248.4.1.1.2.1.0", 0}
--}

--vbind = {
--{oid = "1.3.6.1.4.1.1248.4.1.1.2.1.0", type = TYPE_INTEGER32, value = "0"}
--}


--vbOut, err = ups1:set(vbIn)

--vbOut, err = ups1:set(vbind)
log(vbind)
log(err)
log(index)
--assert(vbOut, err)


--if value==true then

  --vbind, err = ups1:set("1.3.6.1.4.1.1248.4.1.1.2.1.0", 1) 
 
--else
--vbind, err = ups1:set("1.3.6.1.4.1.1248.4.1.1.2.1.0", 0) 
 
   
--end

ups1:close()

[admin]

Here's an example script that sets identity on Mikrotik router via SNMP. You can modify it for your device. Resulting status or error will be visible in Alerts tab.

Code:

require('snmp')

conn, err = snmp.open({
  version = snmp.SNMPv1,
  community = 'public',
  peer = '192.168.1.1',
})

if conn then
  res, err = conn:set({
    {
      oid = '1.3.6.1.2.1.1.5.0',
      value = 'New_Identity',
    }
  })

  if err then
    alert('snmp set failed: ' .. tostring(err))
  else
    alert('snmp set ok')
  end

  conn:close()
else
  alert('snmp connection failed: ' .. tostring(err))
end

[Carlos Padilla]

Hi Admin, thanks for replying. Use the code you told me, but it's not working. I have attached the code adapted to my OID and my IP together with an error log. I have made several modifications but none of them work for me. Thank you and I am attentive to your comments.

Code:

val=event.getvalue()
--Abrir una sesión con snmp
require('snmp')

conn, err = snmp.open({
  version = snmp.SNMPv1,
  community = 'public',
  peer = '192.168.1.248',
})

if conn then
  res, err = conn:set({
    {
      oid = '1.3.6.1.4.1.1248.4.1.1.2.1.0',
        value = '0',
    }
  })

  if err then
    alert('snmp set failed: ' .. tostring(err))
    log (err)
    log ('snmp set failed')
  else
    alert('snmp set ok')
    log ('snmp set ok')
  end

  conn:close()
else
  alert('snmp connection failed: ' .. tostring(err))
  log ('snmp connection failed')
end

Event for ON/OFF_PROYECTOR (0/1/0) 12.07.2019 09:47:23
* string: snmp: bad type (2) prim=0 in index 1

---

Event for ON/OFF_PROYECTOR (0/1/0) 12.07.2019 09:47:23
* string: snmp set failed


I have the library
libnetsnmp 5.4.4-1
luasnmp 1.0.6-2-2

[Carlos Padilla]

Hi, I share with you the script by event that works to turn an EPSON projector on and off using snmp.

Code:

val=event.getvalue()

require('snmp')

conn, err = snmp.open({
  version = snmp.SNMPv1,
  community = 'public',
  peer = '192.168.0.248',
})

assert(conn, err)


if val==true then
 
vbIn = {
  {oid = "1.3.6.1.4.1.1248.4.1.1.2.1.0", type=snmp.TYPE_INTEGER, value = "1"} 
}
vbOut, err, index = conn:set(vbIn)

else
 
vbIn = {
{oid = "1.3.6.1.4.1.1248.4.1.1.2.1.0", type=snmp.TYPE_INTEGER, value = "0"} 
}
vbOut, err, index = conn:set(vbIn)
   
end


conn:close()