On 802.11 networking

Lately I've been having all sorts of Network layer issues on my laptop. For some reason although a Datalink connection is (as Professor Ma would say) entablished with the Access Point, the negotiation of a DHCP lease just isn't happening. I've had to steal access from a neighbour via a painfully slow Rogers connection.

For those aspiring Network Analysts, here is an interesting question. How did I know my neighbour is using Rogers? Well its actually pretty trivial but still useful to know. First using the website What is my IP gives me the address of the WAN interface on the neighbour's "Router". Next I go to Traceroute.org and inspect a few different Looking Glasses - why a few? Just be sure.

Lets consider this example, suppose the neighbour's IP address is, say 99.233.100.100 (from What is my IP). Now lets plug that IP address in to Quest USA (ASN 209) and Telus (ASN 852). (We ensure to select BGP not Ping or Traceroute, although those can be interesting too depending on what we are up to).

From Quest we see:

sh ip bgp 99.233.100.100
BGP routing table entry for 99.233.0.0/16, version 570055897
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Not advertised to any peer
  174 812
 205.171.0.96 (metric 10) from 205.171.0.149 (205.171.0.149)
   Origin IGP, metric 0, localpref 80, valid, internal, best
   Community: 209:888 209:889
   Originator: 205.171.0.96, Cluster list: 205.171.0.149
174 812
 205.171.0.96 (metric 10) from 205.171.0.150 (205.171.0.150)
   Origin IGP, metric 0, localpref 80, valid, internal
   Community: 209:888 209:889
   Originator: 205.171.0.96, Cluster list: 205.171.0.149

And from Telus we get:

show ip bgp 99.233.100.100
BGP routing table entry for 99.233.0.0/16, version 11888182
Bestpath Modifiers: deterministic-med
Paths: (1 available, best #1)
Not advertised to any peer
  852 812
 154.11.63.85 from 154.11.63.85 (154.11.0.161)
   Origin IGP, localpref 100, valid, external, best

Now notice in both answers (Telus and Quest) the bolded lines, I did the bolding. Lets see those two lines:

Quest: 174 812
Telus: 852 812

In both cases ASN 812 appears, now interestingly Quest is supposed to be ASN 209, but they show up as 174 - which happens to be Cogent Communications. How do I know Cogent is ASN 174, because I have almost every damned ASN under 600 memorized... no I don't really, but I've been doing so much Border Gateway stuff lately that I feel like I've got them all memorized. But I do know that 174 is Cogent, not Quest, and even if I did not already know that, I could go to ARIN and ask my friendly neighbourhood RIR, use the string 'a 174' without the single quotes. What about 812? Well we know from the Looking Glass section that 812 is Rogers.

My neighbour is on a shitty Rogers connection, which is why I am not working on my article on space planes but am instead writing about the wonderful World of Internet Routing. As soon as I get my own wireless sorted out I'll get back to other things, I promise.

Now that I've done all that I notice something really interesting, Cogent's POC (Point of Contact) is a NOC (Network Operations Centre) that's very interesting, I always though POCs had to be individuals. Well maybe I can change my ASN POC to be a NOC, but in the meantime I really should be fixing the DHCP issues on my IBM so that I can use TCP, UDP, IP and all the wonderful applications like HTTP, FTP and my favorite, TCP port 17! (Yes the excessive use of acronyms there was intentional.)