Data volume quotas or “bandwidth caps” are restrictions introduced by the South African ISP industry to cope with the introduction of ADSL. Prior to ADSL, the amount of upstream bandwidth required by an ISP to service N users was naturally limited by the fact that telephone calls are expensive: users dialed up, did what they [...]
Tagged ADSL, AfricaINX, MWeb, SATNAC, telkom, uncappedI’ve just read an ITWeb article entitled “Diaspora won’t work in SA” (referring to the soon to be launched Diaspora social network). The article quotes Steven Ambrose of WWW Strategy : “According to Ambrose, only 12% of South Africans have access to the Internet and of that 12%, only 4% have broadband. This means that [...]
Tagged diaspora, trustfabricUntil I can use the same software I use on my two computers, on a mobile phone, I don’t consider the “smart phone” to be a general purpose computing device. Paul Graham has a similar metric, he wants the device to be capable of hosting it’s own development environment. Graham, among many others, has done [...]
Tagged android, iphone, maemo, meego, n900, nokia, smart phoneI’m presenting a talk at the TLUG meeting in Pretoria tonight, on fiber optic networking. These meetings are open to the public. See the link for details.
Tagged fiber optic, presentation, TLUGShortly after my post revealing that RSAWeb (among others) provide hosting for known South African spammers, I got an email from their Technical Director, Mark Slingsby, asking how recent my lookups were1, and requesting me to name the offenders2 so that his sysadmin team can follow up. I replied with a detailed response, noting that [...]
Tagged fail, ispa, RSAWeb, spammersThis morning I read this article on MyBroadband about the ISPA “hall of shame” list of South African spammers, and conducted a quick (somewhat non-scientific) investigation to see where the mail servers for the domains provided on the ISPA list are hosted. After filtering out domains without MX records, MX records without valid A records, [...]
Tagged hosting, ispa, spammersDHCP can be used to set the interface MTU on end hosts using option 26. For example (with dnsmasq), to set the MTU of clients on the lan interface to 1400 bytes, use: dhcp-option=lan,26,1400 I’m using this to work around MTU issues caused by a tunnel. It seems to work well so far… no need [...]
Tagged dhcp, fragmentation, MSS, MTU, tunnelsUpdate: Added MIT License. IP sub-netting is one of the first things one learns about network administration. You have a /22, you want /24′s, 2 bits give you 4 sub-nets. Or you want one /24, so you break the /22 into two /24′s and a /23. Not rocket science. It’s the kind of thing you [...]
Tagged bgp, ddos, prefix hijack, python, subnettingI’ve been playing with BGP-based maps showing links between South African autonomous systems, on-and-off, for a long time. I always got stuck at the graph layout step and was never able to trick GraphViz into doing exactly what I wanted. When I re-visited this project one evening this week, I decided to generate a Dia [...]
Tagged bgp, dia, graphviz, ispmap, python, za internet mapLast week Thursday I registered a .COM domain with joker.com, a smaller registrar that I’ve been using for a few years. They accepted my credit card payment and I immediately configured a blogger.com hosted blog to use this domain. After three hours the delegation for the domain suddenly disappeared from the .COM zone, effectively taking [...]
Tagged .co.za, .com, dns, IS Labs, joker.com, registrar, registry, uniforum/etc/network/interfaces ADSL bgp bind cell c debian dhcp dhcp3-client dhcpcd dns doc DPE ethernet fail fnbconnect home networking hosting hostname ICASA infraco IOS IPv6 IS IS Labs ispa lasers linux mikrotik MTN Business MWeb Neology peering phone-camera policy python routeros SAIX spammers telkom trouble-shooting uncapped vans verizon winbox zimbabwe
