Intermittent http-400 Errors

[=?Utf-8?B?RGFycmVs?=]

I don't know if this is an ASP.NET issue, an IIS issue, or a user browser
issue, but on one of our web applications we have been getting an increasing
amount of 400 'Bad Request' errors. The following is what we know about the
issue mostly from looking at LiveStats and the IIS log:

- It is Intermittent. Most of the time it behaves correctly but the amount
of 400 errors has been increasing in frequency.
- When the 400 does occur it is on a postback, not on the first request to
the page.
- Once the error occurs, it will occur for all subsequent refreshes to the
page.
- There is evidence that sometimes the user is able to submit the page
correctly the first time, but when they come back to that same page later it
produces the 400 error when they try to submit the form. So it does not
happen consistently for the same user.
- ASP.NET does not catch this 400 error. We use the global error event to
catch errors, and while it picks up 404's it is not picking up this 400.
- IIS server 2003, Dotnet framework 1.1.
- It has occured on both IE 6 and IE 7 browsers, with no indication that it
will not occur on others.
- The IIS logs also shows network code 64. Nothing was listed in the event
log.

We have never been able to duplicate this error, but it seems to be
happening to an increased number of customers on the site. This is affecting
our sales. It is high priority for us to resolve this. If no one knows the
answer I would like to be directed to an area where I can get assitance.

Thank You
Darrel

[bruce barker]

400 is a bad request, meaning what IIS received is not a valid http
request. you should run a network sniffer/trace to catch what is
actually sent to IIS.

a common cause is using integrated security which requires connection
keep alives for the out-of-band security exchange messages, and some
proxy server is not honoring the keep alive.
-- bruce (sqlwork.com)

Darrel wrote:

I don't know if this is an ASP.NET issue, an IIS issue, or a user browser
issue, but on one of our web applications we have been getting an increasing
amount of 400 'Bad Request' errors. The following is what we know about the
issue mostly from looking at LiveStats and the IIS log:

- It is Intermittent. Most of the time it behaves correctly but the amount
of 400 errors has been increasing in frequency.
- When the 400 does occur it is on a postback, not on the first request to
the page.
- Once the error occurs, it will occur for all subsequent refreshes to the
page.
- There is evidence that sometimes the user is able to submit the page
correctly the first time, but when they come back to that same page later it
produces the 400 error when they try to submit the form. So it does not
happen consistently for the same user.
- ASP.NET does not catch this 400 error. We use the global error event to
catch errors, and while it picks up 404's it is not picking up this 400.
- IIS server 2003, Dotnet framework 1.1.
- It has occured on both IE 6 and IE 7 browsers, with no indication that it
will not occur on others.
- The IIS logs also shows network code 64. Nothing was listed in the event
log.

We have never been able to duplicate this error, but it seems to be
happening to an increased number of customers on the site. This is affecting
our sales. It is high priority for us to resolve this. If no one knows the
answer I would like to be directed to an area where I can get assitance.

Thank You
Darrel

[=?Utf-8?B?RGFycmVs?=]

Thank you Bruce for your answer.

I had passed this information along to our network staff and web host. And
we will be posting similar questions in network forums.

I would like to verify that this is a network error and not an asp.net
error. Since we have not uploaded any changes to the code lately, and since
the asp.net gloabl event handler does not seem to be catching it, it does
appear to be network related.

If anbody knows anything about this issue that could be asp.net related, or
there is something I could do as an asp.net developer to help resolve this,
please let me know.

Darrel

"bruce barker" wrote:

400 is a bad request, meaning what IIS received is not a valid http
request. you should run a network sniffer/trace to catch what is
actually sent to IIS.

a common cause is using integrated security which requires connection
keep alives for the out-of-band security exchange messages, and some
proxy server is not honoring the keep alive.
-- bruce (sqlwork.com)

Darrel wrote:

I don't know if this is an ASP.NET issue, an IIS issue, or a user browser
issue, but on one of our web applications we have been getting an increasing
amount of 400 'Bad Request' errors. The following is what we know about the
issue mostly from looking at LiveStats and the IIS log:

- It is Intermittent. Most of the time it behaves correctly but the amount
of 400 errors has been increasing in frequency.
- When the 400 does occur it is on a postback, not on the first request to
the page.
- Once the error occurs, it will occur for all subsequent refreshes to the
page.
- There is evidence that sometimes the user is able to submit the page
correctly the first time, but when they come back to that same page later it
produces the 400 error when they try to submit the form. So it does not
happen consistently for the same user.
- ASP.NET does not catch this 400 error. We use the global error event to
catch errors, and while it picks up 404's it is not picking up this 400.
- IIS server 2003, Dotnet framework 1.1.
- It has occured on both IE 6 and IE 7 browsers, with no indication that it
will not occur on others.
- The IIS logs also shows network code 64. Nothing was listed in the event
log.

We have never been able to duplicate this error, but it seems to be
happening to an increased number of customers on the site. This is affecting
our sales. It is high priority for us to resolve this. If no one knows the
answer I would like to be directed to an area where I can get assitance.

Thank You
Darrel