Member Avatar for Funkwarrior

Hi all,

this is my first message and I would to say hello to all the community of Daniweb! Thank you for all your effort!

Well, I've a problem I can't resolve myself:

All the domains on a specific server with IIS 6.0 WinServer 2003r2 on dell 2950 with Broadcom BCM5708c nextremeII are not reacheable by anything kind of browser based on macos or linux Operative systems. But on the same machines, with a virtualisation program, an XP instance view the websites normally.

The Service center of my hoster said there some problems with the driver of the specific netcard, but, for them, all system is up to grade and works 100%.

Can someone help me please?

Thank You!

  • 2 Contributors
  • 10 Replies
  • 211 Views
  • 5 Days Discussion Span
  • Latest Post Latest Post by Funkwarrior

Dani AI

Generated

Brief expert addendum: the symptom set you described (all Mac/Linux browsers unable to reach IIS while a Windows XP VM works) is a classic interaction between Windows' newer offload/acceleration features and an OEM NIC driver/firmware bug. reported the hoster’s Broadcom driver patch fixed it; ’s suggestion to try disabling the OS offload stack was also on point. These features (TCP Chimney / RSS / NetDMA and NIC-level offloads) are known to break or reset TCP connections in some Server 2003 + NIC driver combinations. (learn.microsoft.com)

Practical troubleshooting checklist (safe to follow in sequence):

  • Capture traffic on both sides (server and a failing Mac) so you can tell whether the GET reaches the server and whether the server’s response leaves the box. Note that hardware checksum offload will often make a capture show “bad checksum” even when the wire is fine — Wireshark documents this caveat. (wireshark.org)
  • On the server, toggle NIC advanced options one at a time (via the adapter’s Properties): Rx/Tx TCP/UDP checksum offload, Large Send/Segment Offload (LSO/TSO), Receive-Side Scaling (RSS), and any TOE/iSCSI offload modes. After each change, test a Mac client.
  • Update both driver and firmware for the Broadcom NetXtreme adapter; driver releases and the adapter guide explain the offload options and how they behave. (documentation.help)

Why the VM worked: the VM’s virtual NIC typically doesn’t expose the host NIC’s TOE/VMQ behavior to the guest, so the guest can succeed while the host stack (using hardware offload) fails — that explains the different behavior you saw. Make any changes during a maintenance window and prefer vendor driver/firmware fixes first; disabling offloads is a reliable short-term workaround. (manuals.plus)

Recommended Answers

All 10 Replies

Member Avatar for DimaYasny

first of all

netsh int ip set chimney disabled

are you using http, ot https?
does the site work if you access it with firefox or safari from windows?
also, if you use a simple index.html with some text, does it work?

Member Avatar for Funkwarrior

Thank you for your reply DimaYasny, but I'm not a sysadmin and I don't know what

netsh int ip set chimney disabled

is mean. I'm sorry! :)

I'm using http, the site works well with firefox on Win and a simple data.asp print out the server date works fine on bother mac and win OS..

Thanks for your help!

Member Avatar for DimaYasny

start->run-> and type the netsh command there. press enter afterwards

if you create a simple HTML file, NOT ASP, does that work fine with linux clients?

if you try to pull the page from the linux console, what do you receive? try links and wget

Member Avatar for Funkwarrior

I've to run these commands on the server or on the client?

Member Avatar for DimaYasny

the server of course

Member Avatar for Funkwarrior

Thanks for your support DimaYasny,

Well, after a lot of phone calls at the Call Center of my provider, they found the solution: they're applied a driver patch upgrade for the broadcom 5708C NetxtremeII from dell support site on the Dell PowerEdge 2950. Now everything's works fine but, I don't know with precision what patch they used.

Thank you again for your help!

Have a nice day!

Member Avatar for DimaYasny

it's ok, I know what patch they used
cheers! :)

Member Avatar for Funkwarrior

Really? Can you tell me please?

Member Avatar for DimaYasny

the first one is an MS update that disables ToE (same as the netsh command I have provided earlier)

the second is probably a driver and firmware update for the bcom NICs, available on support.dell.com

Member Avatar for Funkwarrior

Thank you so much!

Best of all,

Funkwarrior.

Be a part of the DaniWeb community

We're a friendly, industry-focused community of developers, IT pros, digital marketers, and technology enthusiasts meeting, networking, learning, and sharing knowledge.