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Computers & Hardware => Networking => Topic started by: Weaver on March 08, 2020, 09:22:48 PM

Title: SNMP
Post by: Weaver on March 08, 2020, 09:22:48 PM
I have a number of devices on my network that speak SNMP, but Iím finding it difficult to locate a useful SNMP app for the iPad. I suppose I could run something on the Raspberry Pi perhaps, as an alternative but GUI-based things are possibly out - I donít know if GUI-based things are usable especially with me having no mouse.

What good things could I do with SNMP?

Also, will I have any security worries ? (I donít want to have to make a dogís breakfast with very messy and unmaintainable firewalling just to fix security problems.)
Title: Re: SNMP
Post by: CarlT on March 08, 2020, 10:49:36 PM
You really want to be using a fixed device to do SNMP polling and receive traps. Your iPad should be doing nothing other than logging into a web interface.

Bunch of software you can use. What are you looking to do?
Title: Re: SNMP
Post by: Weaver on March 08, 2020, 10:51:29 PM
Iím just exploring here: Iím wondering what the technology can do for me.
Title: Re: SNMP
Post by: Alex Atkin UK on March 09, 2020, 05:12:16 AM
In my experience SNMP is a nightmare.  The naming scheme can be so cryptic and it baffles me how often it will give you statistics for a ton of stuff you don't need, then omit to things you do. (typically things like modem stats are missing)
Title: Re: SNMP
Post by: CarlT on March 09, 2020, 08:26:39 AM
https://www.paessler.com/info/snmp_mibs_and_oids_an_overview

Depending on what's exposed, there are standards for MIBs and OIDs, it can be a mine of information

Check PRTG out for starters.  :)
Title: Re: SNMP
Post by: dee.jay on March 09, 2020, 04:11:24 PM
PRTG is nice, and has a half decent amount of "sensors" available on the free version.

One interface of one device is classed as a sensor, so you could easily burn through 100 in a small office, but for a home user it should be fine.

SNMP is my bread and butter - used to support tens of thousands of devices in PRTG for several customers once upon a time.

Carl is right, the iPad would be used to access the web front end. PRTG requires a Windows machine to run.
Title: Re: SNMP
Post by: sevenlayermuddle on March 09, 2020, 06:36:59 PM
I have not worked professionally in data comms for over a decade.

Preceding that, from late 1980s onwards it became normal for marketing managers, just when we thought a project was understood, to suddenly add a requirement that we must support SNMP.   I hated that as it seemed to be just a tick-box, with no clear definition of what functionality was really wanted.   

I also discovered however that if I simply ignored the requirement, nobody noticed.  Might be different these days. :)
Title: Re: SNMP
Post by: CarlT on March 09, 2020, 10:17:15 PM
Very much so. Monitoring has been built around SNMP for a while now.

Other options are, of course, available, but SNMP traps and OID reads are a huge thing.
Title: Re: SNMP
Post by: aesmith on March 22, 2020, 04:29:25 PM
PRTG is nice, and has a half decent amount of "sensors" available on the free version.

One interface of one device is classed as a sensor, so you could easily burn through 100 in a small office, but for a home user it should be fine.

Is it not one function == one sensor?  For example at home here my 4G router is a "device", with multiple "sensors" for example I have LTE traffic as one sensor another with the LTE signal strength readings.
Title: Re: SNMP
Post by: dee.jay on March 27, 2020, 09:06:00 AM
Is it not one function == one sensor?  For example at home here my 4G router is a "device", with multiple "sensors" for example I have LTE traffic as one sensor another with the LTE signal strength readings.

Yes, every single interface on a device counts as a sensor. So 100 is great if you are an SME or home user, but I'd burn through that in a Data Centre in no time :)
Title: Re: SNMP
Post by: aesmith on March 27, 2020, 11:02:56 AM
Sorry, I wasn't really clear.  What I meant is that potentially other functions also add to the sensor count.  So if you're monitoring some IP SLAs, Netflow, etc then the sensor count can easily exceed the number of interfaces.  Conversely if you add a device with 100 interfaces, but only monitor one then that's one sensor, not 100.
Title: Re: SNMP
Post by: dee.jay on March 27, 2020, 03:24:34 PM
Ah I see - yes that is likely the case (SLA monitor etc)

And yes, if you only monitor 1 interface - then yes it'll count for 1.

The clever part of it is, when you install it  - it auto discovers and adds everything to the portal :)
Title: Re: SNMP
Post by: Alex Atkin UK on March 27, 2020, 03:54:35 PM
What frustrates me is modems/routers seem to NEVER include DSL statistics in their SNMP tables.
Title: Re: SNMP
Post by: aesmith on March 27, 2020, 04:23:36 PM
True in some cases.  Billion include a couple of figures, and in fact my old Linksys did as well.  If I remember rightly Billion uses the VDSL MIB even on their ADSL router, but many of the variables are just empty.
Title: Re: SNMP
Post by: Alex Atkin UK on March 27, 2020, 06:51:12 PM
True in some cases.  Billion include a couple of figures, and in fact my old Linksys did as well.  If I remember rightly Billion uses the VDSL MIB even on their ADSL router, but many of the variables are just empty.

Must be very few and far between as I think I've checked every router I ever owned and none had it.

I mean even OpenWRT isn't providing it and it seems Zyxel isn't either.
Title: Re: SNMP
Post by: dee.jay on March 31, 2020, 09:12:21 AM
The trouble is that DSL/VDSL is not typically something you see in enterprises/data centres, so I'd guess that is why there hasn't been much support for it in SNMP.
Title: Re: SNMP
Post by: Alex Atkin UK on March 31, 2020, 07:34:37 PM
True, but then why support SNMP on a VDSL router at all if you're not going to include the VDSL stats?

Its even more bizarre than OpenWRT doesn't have them.  In fact, even monitoring the dsl interface doesn't seem to be working right, the number doesn't seem to be incrementing.  I've tried dsl0, dsl0.101 and the bridge, nothing is bringing any results that make sense.

The Zyxel however IS at least showing the data transfer over the DSL interface.
Title: Re: SNMP
Post by: Chrysalis on April 01, 2020, 02:17:28 AM
The billion modems support(ed) it.  I used to monitor my billion stats in my ukonline days via snmp.  I agree if a modem device has snmp and it doesnt support putting dsl metrics on there, then it seems counter productive.
Title: Re: SNMP
Post by: aesmith on April 01, 2020, 02:43:44 PM
Did your Billion support the full MIB?  My 7800DXL only returned a few values from the MIB, for example Noise Margin but not any of the error counts.  Based on some quick tests Cisco supports the standard MIB VDSL2-LINE-MIB.

I think the issue may be more that typical home users don't use SNMP, rather than enterprises not using DSL. 
Title: Re: SNMP
Post by: Chrysalis on April 02, 2020, 05:26:06 AM
I dont think it was absolute full on stats, I monitored sync speed, snrm and I think maybe attenuation also.  The prime purpose at the time was to monitor how well SRA was working.

I have never tried to monitor via SNMP on my newer 8800nl.
Title: Re: SNMP
Post by: aesmith on April 02, 2020, 12:57:44 PM
My Zyxel 8924 supports ADSL-LINE-MIB.  I'm not sure how completely it supports it as there are zillions of entries in the MIB so those that it doesn't return values for may be irrelevant.