FULL PRODUCT VERSION :
OpenJDK Runtime Environment (IcedTea6 1.8.7) (6b18-1.8.7-2~squeeze1)
OpenJDK Client VM (build 14.0-b16, mixed mode, sharing)

ADDITIONAL OS VERSION INFORMATION :
Linux l-at9676 2.6.32-5-686 #1 SMP Mon Jun 13 04:13:06 UTC 2011 i686 GNU/Linux

A DESCRIPTION OF THE PROBLEM :
calling NetworkInterface.getNetworkInterfaces() on linux returns corrupted results if some interface's index is over 255 (which is sometimes the case for virtual interfaces).

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. call NetworkInterface.getNetworkInterfaces() on a machine where some IPv6 enabled interface's index is over 255 (larger than 2 hex-digits)

to check : call "cat /proc/net/if_inet6" in a shell. If any of the number in the second column is over 2 hex-digits, the bug will occur. Example:

00000000000000000000000000000001 01 80 10 80 lo
fe80000000000000f8b164fffe2eaa8e 17f 40 20 80 veth0sACuM
fe80000000000000021517fffee3ae55 04 40 20 80 eth0

2. browse the resulting enumeration : in contains corrupted NetworkInterface objects which doen't correspond to any interface on the machine. Calling methods such as isUp() or isVirtual() on these objects will throw a SocketException

EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
a list of existing NetworkInterface object
ACTUAL -
a list containing some existing NetworkInterface mixed with corrupted, non existing NetworkInterface objects

REPRODUCIBILITY :
This bug can be reproduced always.

CUSTOMER SUBMITTED WORKAROUND :
the bug is caused by an incorrect format string in the C fscanf function, in /openjdk/jdk/src/solaris/native/java/net/NetworkInterface.c , [line 1108 in openjdk-7-fcs-src-b147-27_jun_2011.zip]

the format string is
"%4s%4s%4s%4s%4s%4s%4s%4s %02x %02x %02x %02x %20s\n"
ans shoud be
"%4s%4s%4s%4s%4s%4s%4s%4s %03x %02x %02x %02x %20s\n"
to be able to parse entries withe a second colum larger than 2 hex-digits.

modifying this line solved the problem for me.