Yes, You Too Can Be an Evil Network Overlord With OpenBSD 49
badger.foo writes "Have you ever wanted to know what's really going on in your network? Some free tools with surprising origins can help you to an almost frightening degree. Peter Hansteen shares some monitoring insights, anecdotes and practical advice in his latest column on how to really know your network. All of it with free software, of course."
From the article: "
The NetFlow protocol was invented at Cisco in the early 1990s. It's designed to collect traffic metadata, where the basic unit of reference is the flow, defined as the source and destination IP address pair, the matching source and destination port for protocols that use them, the protocol identifier, time started and ended, number of packets sent, number of bytes sent, and a few other fields that have varied somewhat over the NetFlow versions. ...
On OpenBSD, various netflow sensors and collectors had been available for a while when the new network pseudo device pflow debuted in OpenBSD 4.5."
Ho Humm (Score:1)
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Post it on soylentnews and see what we/us think...
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You have to know this stuff and think it is for children if you want a job at the NSA.
Fake characters (Score:2)
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Still not nearly as useless as SlashBI, though!
All thanks to OpenBSD, eh? (Score:5, Informative)
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Plus, OpenBSD 4.5 is about ... 5 years old, or something like that!
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OpenBSD 4.5 is when support for the NetFlow protocol was introduced... as mentioned in the article sourced by this /. entry.
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Yes, all you need is tcpdump, punchcards and butterflies.
What do you use then to limit the bandwidth to/from certain sources, and monitor the bandwidth of certain types of traffic, e.g. on Linux? A port of this would be useful. In my usage scenario, a few hundred users share a upstream network, and the traffic from a few (youtube, streams) can dominate the others, making web pages slow for the others. A fair distribution would be nice, but when fewer users are online, the full bandwidth should be available.
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It isn't that no other tool exists, it's that it's done well compared.
Same with pf vs iptables.
Get a pf configuration file, and an iptables configuration file. Show the two to someone who doesn't know much about routing. They will likely be able to tell what the pf file is doing, and be clueless about the iptables file.
Nobody is saying that this is "news" (Score:4, Insightful)
Metadata = Spying! (Score:4, Funny)
It's designed to collect traffic metadata, where the basic unit of reference is the flow, defined as the source and destination IP address pair, the matching source and destination port for protocols that use them, the protocol identifier, time started and ended, number of packets sent, number of bytes sent, and a few other fields that have varied somewhat over the NetFlow versions.
Alert the authorities. The three-letter folks want to get some of this metadata!
Good (Score:2)
oh yeah well wait until the hear about SNMP (Score:2)
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huh? (Score:2)
Wouldn't just about everyone who comes here know what netflow is? Why openbsd? netflow is available everywhere now.
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Wouldn't just about everyone who comes here know what netflow is?
Not that I disagree that this isn't particularly newsworthy, but why would you assume most people who come here would know what netflow is?
There was no entrance exam when I registered...
but... I'm already a network overlord... (Score:3)
Does this mean that I need BSD to become Evil.....?
Re:but... I'm already a network overlord... (Score:5, Funny)
Does this mean that I need BSD to become Evil.....?
No but it helps.
Dumb alignment joke incoming (Score:2)
OpenBSD is for Evil Network Admins. OK, I can accept that. So what would Windows be for? Lawful Evil, I would assume. Same for OS X. Extending that, Linux might work for True Neutral, or maybe Chaotic Good. HURD is obviously Chaotic Neutral or Chaotic Evil.
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I ,for one, (Score:2)
welcome our new evil OpenBSD network overlords.
Worst way to do it... (Score:2)
This is just a basic "How-to use Netflow on OpenBSD". Nothing more.
IMHO, Netflow is interesting ONLY if you have no other way to gather info from hardware routers/switches. It's the only protocol likely to be supported.
If, however, you can just mirror a port you're interested in (eg. the uplink), as you already would be doing with an IDS and similar, you don't need to bother with Netflow. Instead, you can get all the info you could want, with trivial ease, just by installing and running BandwidthD-2.x:
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