Small Dropbear

JFFNMS 0.9.3 1st release candidate

I have been putting a lot of testing into jffnms lately.  I have been very lucky to have had someone with the time and patience to try out various sub versions and give me access to their results.

The end-result of all this testing is a much, much less buggy JFFNMS.  There have been a strack of problems with caching results, for example, where status would not be updated or even worse the status of one device impacted on another.

The poller parent scheduler had a problem too where it would almost always sit in the first child starving the others of work which slowed things down. The scheduler now is a lot fairer across the children giving a speed up. I’ve heard speed-ups of 15x for this one change alone.

I also had a curious bug where if a device was set to not gather state it still did and created events but not alerts.  This meant your event table was spammed with down interface alerts even on interface you know are down and you turned state checking off.  0.9.3 now does it the right way.

The first RC is now uploaded and can be found at https://sourceforge.net/projects/jffnms/files/jffnms%20RC/ to try out.

I’m a little worried that the pollers now run too fast and could overwhelm the usually crummy control stack found in network devices for parsing SNMP.  I’m interested to hear how people find it.

SNMP Information from your DLink DSL-300 ADSL Modem

Not many people know it, but the DLink DSL-300 ADSL modem has SNMP management capabilities. And for such a small and cheap network device, its not too bad an implementation of it. Or perhaps I’ve just seen a lot of dead-awful ones to compare objectively. Of course the displaying of the private community in the MIB, which is something the DSL-300 does, is a pretty dumb idea.

I should point out right here that these instructions work for me. They might work for you, or you might just find some easter egg in the modems firmware that turns it into a smoke machine So do any of this stuff at your own risk.

You will have to connect to the modem using a serial port first to find out the IP address and change either your computers or the modems IP address so they are in the same network. Note that this address is not the same as the one your provider gives. And the communities are the very hard to guess public and private for read-only and read-write respectively.

The modem has some of the standard SNMP MIBs that anyone who’s played with SNMP will quickly recognise, such as.

• system information
• interface information including the ifTable
• IP MIB – Packets in out, discards etc
• ip routes
• TCP MIB
• SNMP MIB, which is statistics about the agent itself
• SNMPv2-SMI::mib-2.17.4

All pretty standard stuff you see in pretty much any device. All the good information is always found in the private enterprises part of the MIB, and the DSL-300 is no exception. The problem is that if you ask DLink about it, they will tell you nothing. The nice thing about DLink is they’re pretty consistent about annoying the hell out of their customers by denying them technical information.

With that rant out of the way, its time to work out for myself what these values are for. I’ve got some worked out but it will take some more time to get it all clear and possibly some will never be worked out, thanks DLink!

All OIDs start with private.enterprises.171.11 There are quite a few gaps so if you know what the missing values mean, drop me a line.

Some definitions you might find useful:

• Error Second (ES) – Any second where at least one bit error was received.