Friday, May 21, 2010


watching skype here in the lab. sending a few messages from here to jingping. interesting thing is that i don't have a direct link to her. instead, skype only reports having connections with computers at NYU - several of them, six different hosts. maybe they're using me as a relay? or, i could be part of a similar set of harvard-located hosts. here, instead of 36268 or whatever it is at home, the port being used by skype for those UDP messages is always 38253. i also see that i'm sending to each of those NYU hosts from the same port, but receiving from a different port from each one. i'm guessing that all these connections are for the same purpose, and that again for each of those users the port number is the same for all their connections.

oh well, more later. maybe something interesting will happen.

Tuesday, May 18, 2010

chinese-american economics

unrelated to the internet, but i did realize this last night, so it may as well go down here.

i'm aware of two facts, to which we are all constantly exposed by various media:

A. the US buys lots of stuff from China, more than China buys from the US, so there's a trade imbalance. this means the Chinese are stuck with extra $$ that they can't spend, so they loan it back to the US to continue the cycle.
B. the Chinese 元 is tied, in part, to the US $$.

i knew these things already, but didn't realize they were directly related. but they are - and so far i think it's a one-way relationship, in that A) makes B) necessary. i understood it in terms of the following cycle:

1. China companies manufacture goods
2. US companies purchase China goods with $$
3. China companies purchase US goods with the $$ they accumulated
4. China companies have $$ leftover
5. China companies need to pay for domestic costs and profit, but can't spend $$ in China
6. China companies give their $$ to China govt, which gives them China 元 in exchange
7. China govt loans $$ to US treasury
8. US treasury loans $$ to US banks
9. US banks loan $$ to US companies
10. (back to 2.)

this seems to work. I don't know anything about how sustainable it is, though I think I see how you could get to know, or have a strong opinion about, something like that by looking at this process in detail.

anyways, why does A lead to B? because of 6). in order for 6) to be a fair deal, so that the China companies can know they're getting exactly their dollar's worth in the trade, the $$ and the 元 should be closely linked. in essence, those $$-linked 元 are like $$ printed in Chinese form, with the actual $$ stored away as ensured value, like gold - this is why they call $$ a reserve currency.

so apparently, this journal is entirely devoted to me figuring out things that everyone else knows already.

Sunday, May 16, 2010

what is in my packet net?

a boring post, to start: i'm just going to go through the list of what packets i caught during a 780 second capture. skype was on, as was xdict and its incessant search for the kingsoft mothership, which is currently routed to ARKIV itself.

first on the list:
robtex suggests that this is some sort of porn locus, responsible for porn spam and who knows what else. sent one packet from their http port 80 to my port 19246, which is for i don't know.

multiple, periodic IGMP signals, labeled "membership report". i see this all the time, sent to apparently, this is just to establish my presence on the network, so that the routers and other whoever know i'm here.

there were 8 apparent skype contacts through port 34268. what i understand is that this is how different skype hosts find eachother. what i don't understand is why for me it's always 34268, while its always different ports for the others. could it be that for them it's always their number? maybe i'm a member of a particular skype class - the port 34268 class. really, i have no idea. these are always UDP packets, call and response, usually just once, always intiated by ARKIV. and, as i mentioned before, i see them even when skype is off, but ARKIV doesn't respond then.

BROWSER: host announcement. i assume this is something like the "membership report" above, but i don't know what makes it different - ARKIV runs a browser service, and there are browser elections, to select a browser which will keep track of all the potential browsers.. argh.

here is a succinct description: packet from, originating from Argentina, from port 1217 to 1434 - 1434 was the way in for something called the SQL slammer worm. SQL is a microsoft database server program - what i received was a single SSRP packet, which is a protocol specially designed for use with the SQL thingie. anyways, one hit, nothing else (presumably i am not running an SQL database server).

so really, that's it. i found a paper on principles of routing in between networks, but haven't read it yet. my learning progress is stalling.

China 222 part 3

not much going on - watched a couple of scans, but haven't studied much. saw the same scan, on ports 8085, 9415, 3246, 9090, and 8090. it probably spins around every few hours, from what others have said on got a single hit from, another chinese location, on a single port. this one actually had a domain name:

read a bit about routing a few days ago, and got a bit of a sense for it, but not really - but then, Jason gave me a great piece of information that I hadn't gleaned yet from my browsing: routers and other computers broadcast their addresses and routing information across the networks. this is how routing tables get their information. i'm still not totally clear on it, but i'll figure it out.

Jason also suggested i get around to learning how to use linux, and install at least a virtual version of it to use, since that's what real internet people do. i may do that, if only for the fun of it.

but anyways, nothing much learned lately. slow week.

Wednesday, May 12, 2010

China 222 part 2

And, got scanned again by, on ports 8085, 2479, and 8090.

DNS server

ok, just got home, thought i'd look at the monitor.

nothing much going on, except i see two reciprocated queries to an address i recognize as something that comes up often as a comcast address - both packets were DNS packets, which as i take it are a type of UDP packet, or maybe not. anyways, i guessed that the address must be a DNS server. since i usually am not using the web browser when i look at the monitor, i wouldn't have noticed this before.

so, i google it and sure enough, is the primary comcast DNS server for massachusetts.

now, one of the queries was for the institute FTP server, which i used to get a file. the other was for, which i do not like, because i did not know google was running something in the background on my computer. the address was then contacted and some packets were traded, a couple were HTTP messages saying "update". i'm going to find out what it is, and kill it. (could be Chrome which i have installed but don't use. i don't have any google plugins or anything for firefox. Chrome must go.)

China 222

maybe a better name for this log should be "what random thing did i see today".

1. it's hard to type in a wrist brace. that fits with "what did i learn today", so..

2. saw four packets from China, from address they soaked into 4 ports which i lost because i restarted the monitor - got distracted at the wrong time, lost good information... i did scan the address and found that it may be a server - google indicates it could be a proxy server: open ports on 1026 and 3389. note comments here and especially here. apparently multiple Chinese IPs starting with 222 are pushing scans all over the place, irritating lots of people.

Sunday, May 09, 2010

not much 2

ok, this is interesting. another packet from the host at that address has just about all of its ports open. i haven't seen that before. is this some sort of lure?

not a lure - i think it's an open proxy. all those open ports are so that other hosts can use it as a proxy for whatever service they want. i can't find any resource that actually confirms this (and i think that having all ports open doesn't necessarily mean it's an open proxy), but i think that's what it is.

always something new to learn...

not much

just observed a sweep from IP, "", looking into port 1137. a bit of news suggests this is a vulnerability search. the signal is coming from an IRC line, port 6667. they must be looking at IRC logs and sweeping those addresses, since i've actually been on IRC in the last couple of weeks (and last night).

another thing, i also saw (for the first time) some nonreciprocated requests for port 34268 while skype was turned off. looking for a relay? i scanned the source and it doesn't actually seem to be a skype host, though maybe i waited too long, after they had turned it off. instead, they actually had unfiltered, closed ports 5800/5900, which are used for remote desktop viewing. also, no clue as to the OS, so i don't know what it actually is. another user? something else? it's another comcast host, presumably another user, but who knows?

i'll check it out again later.

Thursday, May 06, 2010

internet metaphors

okay, this is kind of dumb, bust since i haven't learned anything new lately, it's all i've got.

actually, i thought of this a few days ago. i was at the taekwondojang, thinking about how the classes work. (almost) every class starts the same way, regardless of who the teacher is, with a set of warmup exercises. different teachers will count a little differently, faster or slower maybe, but everyone does the same exercises. next, we start going through techniques in the lineup, and the first is always "riding stance to the left, left-hand punch". next technique will usually be "step forward front stance, low-section guarding block".

so, up to this point things are the same no matter who the instructor is, no matter what the rest of the class is going to be about. from here, things are still predictable to a point - after the low-section blocks, we'll probably do mid and high section blocks, maybe with a punch after the mid-section blocks. next, we go to fighting stance and start doing kicks, with front kick and punch first, round kick and roundhouse punch next, then sidekick with knifehand strike. it gets less and less predictable after this.

by the end of the lineup, we've probably done a couple of techniques that haven't come up in at least a week or so in other lineups. then, the rest of class will focus on a few specific techniques in some permutation of the "find a partner" game.

what this has to do with the internet is that i realized that the course of a given class could be analogized directly to a traceroute, assuming a single start location. the first few steps away from the local host are the same every time, but depending on the destination eventually the paths will diverge. the warmup and starting techniques are like the local network path out, the later techniques are like the area network, where there are a few possible large routers to choose from, and the remainder of class is like the ultimate path and network destination. kind of.

really, you could apply this structure to all sorts of things, where the first few steps are the same, but eventually there's a divergence and then different paths to disparate destinations. in a lot of ways that's how the brain works, how distribution networks of all kinds operate, etc.

like i said, not too interesting, but it's all i've got for now.

Saturday, May 01, 2010

local network

i mentioned earlier that i had tried the traceroute scan on the institute's local network. i had, but it was so dense that trying to look at the graph caused nmap to die. i did it again today, but carefully collapsed the densest nodes, so i could see the 'backbone' of the network. what i saw was interesting, and implies that my thinking was kind of mistaken.

i had been thinking that i would be looking at the institute network - that the institute must have set up a local 192.168 network within the Harvard system, and that by scanning that prefix (up to, which was where addresses seemed to stop existing) i would get back a picture of the institute network. instead, i saw that the scan went out into the Harvard 128.103 network, then back into the local network. I think this may have been scanning into systems outside of the Institute, and except for the hosts themselves (on the other side of the Harvard nodes) i got back no IP info, so couldn't see the structure. what i could see was that hosts with names on my side of the Harvard nodes all were associated explicitly with the institute (having the institute initials in the hostname), while those on the other side did not.

but, from institute out, i could see that there's a single way out of the institute network, connecting to two nodes both named something like 'core' (i don't have the scan here at home to look at). one of these led into many, many other private network hosts along those blind pathways, and so did the other, along with leading to the node that exits the system into NOX, or level3, or wherever the localhost is pointing.

so, point is, a traceroute to another address with the same prefix as the localhost may not traverse only other hosts with the same prefix. i had assumed that the 192.168 network was somehow self contained, that any hosts i saw within it must be linked through other 192.168 hosts. apparently this isn't necessarily how it works. i have more to learn.

(actually, i had noticed this last week, in scanning my comcast prefix - i found other systems separated from me by large interchanges with different prefixes (but prefixes common to other interchanges), but themselves having the same prefix as mine. i didn't understand it at the time, but forgot about it. this bugged me more, probably because of the 'private network' label attached to 192.168.)