Subject: grow: 'Embedding Globally Routable Internet Addresses Considered Harmful' BCP

From: Dave Plonka <[email-masked]>
Date: Fri, 18 Feb 2005 10:29:36 -0600

GROWers,

Thought you might find this an interesting recent example of the
problem we dealt with in draft-ietf-grow-embed-addr.  (Haven't heard any
progress on an RFC/BCP number since we were notified in December.)

Dave

----- Forwarded message from CCO Field Notice -----

Title: Cisco Field Notice: AutoSecure Bogon Filter Potentially Causes
Blackholing of Internet Traffic

URL: http://www.cisco.com/en/US/customer/products/sw/iosswrel/ps5207/products_field_notice09186a00803e13e9.shtml

Posted: February 16, 2005

Summary: When the IOS feature AutoSecure is used to lock down a router,
a Bogon Filter list can be automatically created and applied to the
Internet-facing router interface to block IP packets with spoofed
source addresses.

A bogon is an informal name for an IP packet on the public Internet
that claims to be from an area of the IP address space reserved, but
not yet allocated or delegated by the Internet Assigned Numbers
Authority (IANA) or a delegated Internet registry.

The bogon filter list created by AutoSecure is hard-coded into IOS, and
hence, is out-of-date with current IANA address space allocations.
When this filter list is applied, the potential exists for legitimate
Internet traffic to be denied.

The effect will be noticed when Internet traffic sourced from these IP
addresses is blocked by the out-of-date bogon filter (access-list),
resulting in a traffic blackhole condition.  This is further described
in the Problem Symptoms section of this Field Notice.

----- End forwarded message -----

-- 
[email-masked]  http://net.doit.wisc.edu/~plonka  ARS:N9HZF  Madison, WI
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