Archive for the ‘Uncategorized’ Category

Ethernet AC switch

Sunday, September 19th, 2021

Frequently it’s required to have some way to know whether or not you have AC power, or whether you’re on battery. A common trick on Mikrotik is to monitor the input voltage. When, however, you have a good DC UPS rather than running straight off the batteries this hack simply isn’t available (of course a really good unit will have SNMP and traps hopefully), or if you have some other router which can’t provide you the input voltage.

Enters the Ethernet AC switch, backed by an AC relay.

Soccer Fever and those (horrid) Vuvuzelas

Friday, June 18th, 2010

So I got stuck on some mathematical calculations to get some multi-level paging system done. And getting the breakdowns right. And someone discovered … well, some may recall the blue-bulls hack we pulled on google a whilst back. Well, by now I reckon you can add the two together.

Vodacom – still messing with TCP/IP?

Monday, May 24th, 2010

Some of you may recall that a whilst back I wrote a blog entry (two actually) regarding Vodacom messing with (and breaking) TCP/IP. Specifically they adjust (present tense seeing that it’s still happening) the ISN from the TCP connection initiator (client) to the server, and they hold up RFC 1948 (here) to substantiate why they do this. As explained in my previous entry regarding this issue their reason is bogus and invalid. I additionally proceeded to explain why their inherent disregard for the TCP/IP standards by which the rest of the world abides in fact creates additional exposure for exploiting such vulnerabilities. Whilst my response at the time was quite harshly phrased it remains valid. (more…)