5% of the Net is Unreachable

dasheiff writes "A BBC Story says US researchers reveal that up to 5% of the internet is completely unreachable. However the most interesting part is that they reported that many of the lost net sites flare into life briefly when being used to send spam or to launch attacks on other parts of the net."

Comments

The article mentions US military sites

[Inthewire]

...the article says those sites are "old" and "unlisted due to age" (not direct quotes)

Maybe they just, um, are delisted due to paranoia, perhaps justified?

Pardon?

[justinstreufert]

This instantly strikes me as sort of dumb. Unreachable? By whom? In what way? What were the methods? Are you talking about IP addresses or domain names? Did you take into account:

• Unallocated IP blocks
  
• Unused allocated blocks that are being sat on by their owners
  
• Dialup, DSL and Cable-modem users
  
• Sites that are down
  
• Sites that do not accept ICMP (or whatever protocol they used)
  
• Desktop computers that people turn off
  
• Firewalls that pretend they don't exist
  

The problem with lost peering agreements between ISPs causing partial 'net outages is well-understood. So what exactly have they measured here?! Seems like a shaky story to get one's name in the news.

Justin

This leads to an interesting possibility

[Goldenhawk]

... that much spam could be identified and stopped more easily by careful tracking of the routing information. The article (actually you have to follow the PDF link to get the real information, not just the executive summary) points out that much of the spam identified came from sites that were established and routed, then sent out the spam, and then shut down again immediately.

Seems to me that you could make some progress against the spam by simply refusing any email from a domain that hadn't been recognized on the net for at least several days or maybe weeks.

If you haven't followed the PDF link, there are some interesting time history graphs of various routing parameters. Worth checking out.

repeated article...

[Raleel]

actually,a BBC rehash of an article that was up a month ago

http://slashdot.org/article.pl?sid=01/11/15/0517 23 7&mode=thread

Research paper

[hearingaid]

It's irritating how people don't even read the BBC quick-article, but for those who actually want to know what the researchers figured out: the paper is here; it's in Acrobat format, sigh.

MILNET doesn't rely on DNS

[Animats]

The MILNET side of the Internet still uses fixed "hosts.txt" tables to some extent, rather than domain name servers. This keeps critical communications going even if DNS is messed up. (The DDN people never really liked BIND, which they didn't contract for; Berkeley did it on their own, without thinking through the security issues.)

MILNET uses IP addresses in the same space as the public Internet. The MILNET is normally connected to the rest of the Internet through gateways, but during crisis periods, those gateways are sometimes turned off. After September 11th, much of the MILNET was inaccessable from the public Internet for a day or two. That may be what those researchers saw.

Slashdot on Exodus

[fliplap]

At the momement, Slashdot, as well as many other Exodus hosted sites such as google and ebay are completely unreachable from many parts of the net. I'm typing this via lynx ssh'd into my account at ASU and I am for some reason able to reach them. It appears that anyone currently on the @home network is unable to reach exodus sites, as well as anyone on the axinet network. I can't confirm anyone else's problems but this is what I've seen.
At first I though thats what this story was refering to