Merge the real site metadata into this repo

_posts/2009-11-30_fun_with_graphs.yaml

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+date: 2009-11-30
+tags:
+  - programming
+  - networking
+title: Fun With Graphs
+---
+I've always been utterly fascinated with graph theory, mostly with its
+applications to networks. As an added bonus, they can be represented with
+pretty pictures!
+---
+[![NYS Network](/media/img/fun_with_graphs/nys-network-thumb.png)](/media/img/fun_with_graphs/nys-network.png)
+(click on image for full-sized version)
+
+That graph represents the network behind Nucor-Yamato Steel and Nucor Castrip
+Arkansas, sanitized of sensitive information of course. All of the nodes are
+Cisco switches, the yellow boxes representing backbone switches (6500 series
+to be exact). This graph is part of the network information system that I've
+been working on during the majority of my internship at NYS and gets auto-generated
+every day, along with more centralized graphs on a per-switch basis.
+The way the system works is that a periodic Python script goes out to a list of
+known switches and gathers CDP neighbor information as well as the MAC address
+tables. Then Nmap scans are ran every 6 hours to scan for hosts, gathering IP
+addresses, hostnames, and MAC addresses. These MAC addresses are correlated with
+the MAC tables from the switches to determine which hosts are connected to which
+ports on what switches. The CDP neighbor information also gives which switches
+are connected to each other, giving a full scope of how the network's connected.
+The script which generates the graphs grabs all of that information out of the
+database, uses NetworkX and pydot to create the graph, and then graphviz to render
+it into a PNG image. The graph is pretty plain, though. The real version shows
+switch names and IP addresses. Since the time between graph generation is so long,
+any more useful information that I could throw onto the graph would quickly become
+outdated. My grand scheme is to make a quickly-updated graph showing live stats like
+switch load, link load, link types (fiber, twisted pair, wireless), downed switches,
+etc. That way, I (or the network supervisor, I guess...) could have a big-screen TV
+displaying the live health of the network.
+
+I've been asked what parameters I set to get that graph to look that way. I didn't set anything special in code, it's all in the command line:
+
+        twopi -q -Ksfdp  -Tpng -Goverlap="prism" -Eoverlap="prism" -Gsplines="true" -Gratio="compress"  -oclean.png clean.dot
+
+Really, I'm just a data visualization nerd looking to get a fix.