Welcome to ISAserver.org

[incorrect TCP checksum]: SSL]

Users viewing this topic: none

Logged in as: Guest

Printable Version

All Forums >> [ISA Server 2004 Firewall] >> Access Policies >> [incorrect TCP checksum]: SSL]

Page: [1]

Message

<< Older Topic Newer Topic >>

[incorrect TCP checksum]: SSL] - 14.Apr.2006 10:13:00 PM

T_Lawson

Posts: 50
Joined: 6.Jun.2002
Status: offline

A handheld application fails to connect when using ISA (2000 or 2004) as a proxy server. PC's that connect to this web site work fine but handhelds fail. If the handheld is behind some other firewall (not ISA) and not configured to use a proxy it works fine.

ISA log shows "Initiated Connection" followed by "Closed Connection".
A network trace shows '[Unreassembled Packet [incorrect TCP checksum]: SSL]'

Any ideas how to make this application work through ISA 2004? Thanks.

Post #: 1

Featured Links*

RE: [incorrect TCP checksum]: SSL] - 15.Apr.2006 12:03:37 AM

ClintD

Posts: 1833
Joined: 26.Jan.2001
From: Keller, TX
Status: offline

I've seen this error so many times I don't even pay attention to it anymore. Most network card drivers offload TCP Segmentation functions to the NIC itself and by the time Ethereal/Network Monitor see it, this is the result. Is there anyway to allow the application temporarily over HTTP (no SSL) until you can get a network capture of the failure?

It is possible that a network device is causing the failure, but it seems unlikely due to the failure being isolated to the hand held devices.

< Message edited by ClintD -- 15.Apr.2006 12:04:49 AM >

(in reply to T_Lawson)

Post #: 2