UC540 and corrupted PDF files

[JOHN THIEN]

I have a client with a UC540.  It is configured as their Internet router.  Seems to be working okay.  It is directly connected to a Time Warner modem.

There are some PDF files they cannot accesss from a certain site.  They can access PDF files from other sites.  And I can access the PDF files they cannot access from my location (but I don't have a UC540).  We cannot figure out why only files from this site are problematic.

When they try to click on the links to the PDF files in question, they get an error message ("The file is damaged and could not be repaired") from the PDF viewer.

Here is the web page (it is a US Gov't page):

http://www.ams.usda.gov/AMSv1.0/ams.fetchTemplateData.do?template=TemplateQ&navID=CommodityPurchasing&leftNav=CommodityPurchasing&page=CommodityPurchasing&acct=AMSPW

The links in question are in the "Resources" sidebar on the right-hand side.  None of those sidebar links that say "PDF" will work.  Many other PDF links on the same page work fine.

I'm using IE10 on Win7.  Chrome behaves the same way, but instead of the error message it just looks like the file doesn't open.

Any ideas on why this wouldn't work?  Or how to debug?

[paolo bevilacqua · Accepted solution]

Are you using PPPoE or "IP inspect"?

In any case, you should post relevant configuration.

[JOHN THIEN]

Sorry for not providing more details, but your message gave me enough data to figure it out.

I use CCA for configuration.

The Firewall on the UC540 was enabled and set for maximum.  It is my belief that there was something going on with those documents on the ams.usda.gov site that was not compliant with http standards.  Maybe the server was sending more data than it said it would send via the content-length header.  I don't know, but the filtering on the UC540 did not like it one bit.

So I reduced the firewall level and it is now working.  But of course, it is a compromise.

Anyway, thank you for pointing me in the correct direction.

[paolo bevilacqua]

When you have NAT, no firewall is needed. It's there just to satisfy marketing.

Thank you for the nice rating and good luck!