{"id":965,"date":"2008-08-10T21:14:20","date_gmt":"2008-08-11T01:14:20","guid":{"rendered":"http:\/\/blogs.n1zyy.com\/n1zyy\/?p=965"},"modified":"2008-08-10T21:14:20","modified_gmt":"2008-08-11T01:14:20","slug":"geek-5","status":"publish","type":"post","link":"https:\/\/blogs.n1zyy.com\/n1zyy\/2008\/08\/10\/geek-5\/","title":{"rendered":"Geek"},"content":{"rendered":"

I came across a reference to cable modems speaking SNMP<\/a>, and though it’d be neat to have something like Cacti<\/a> query my cable modem periodically to see bandwidth usage.<\/p>\n

Comcast, though, blocks SNMP access. I initially thought this was pretty cheap, but it turns out that it’s for good reason: while I’ve always thought of SNMP as a read-only way to see bandwidth usage, it turns out that it’s also able to set<\/em> data, and that’s how much of the configuration is done. Thus they don’t really ‘block’ SNMP, as much as hide it from customers. From what I’ve read, they set a random ‘community’ string that only they (and those who can read the config files the cable modems pull down at boot), but further limit access to certain IP ranges.<\/p>\n

But in the course of scanning for SNMP devices on my network, I did<\/em> get a hit, from an unlikely source. It seems that our network printer<\/a>, a consumer-grade inkjet with an Ethernet port, has an onboard webserver and an SNMP server.<\/p>\n

Unfortunately, it seems they don’t publish MIBs<\/a> for the output of the OfficeJets, meaning that, aside from some of the standard levels, we’re left to guess. I’ve put the output of an snmpwalk<\/a> up on my webserver for anyone curious. Some potentially valuable data:<\/em><\/p>\n