hold off on MS05-019

[tbrennans]

from MS:

From MS:

There is a known issue on this and I would suggest waiting for the
corrected 05-019 patch. I spoke to one of our escalation engineers and
Private fixes are undergoing testing at the moment for Windows 2003,
Windows 2000, and Windows XP. A Microsoft KB article is being written
and has been assigned the number 898060, but as to this time, that
article is not publicly available.

Here are details of the problem, cause and one of known workarounds.


PROBLEM:

Connectivity between servers across networks may fail. The
connections type may vary, connections to Terminal Servers, DC
replication across WAN links, File Share access etc.

CAUSE:

The problem is that when the sender receives an ICMP Destination
Unreachable - Fragmentation Needed - message from the router, the tcp
incorrectly increments the host route count (default max is 1000 part of
MS05-019 change).

So, over a course of time, we reach the max count pretty quickly.
After the max is reached the sender will ignore the ICMP message.

WORKAROUND

1. Set Default MTU size to the size of the next hop, or rather the
largest size the routers can handle.

Refer to

http://support.microsoft.com/kb/120642/EN-US/

MTU

Key: <Adapter Name>\Parameters\Tcpip
Note In Windows 2000 and later this value is under the following key:

Key: Tcpip\Parameters\Interfaces\<ID for Adapter>
Value Type: REG_DWORD Number
Valid Range: 68 - <the MTU of the underlying network>
Default: 0xFFFFFFFF