Hi group.

What issues are known concerning interoperability between WinPcap and Network 
Load Balancing in Windows?

I occasionally perform a packet capture to troubleshoot client problems.  
Noticed an anomaly with captures on Windows servers running Network Load 
Balancing. Here are my observations:

The lab consists of the following:

4 servers
1 firewall appliance with 1:1 configured for the NLB IP address
8 clients

>From any server in this lab farm:
Inbound traffic is captured correctly from the NLB NIC. I see all traffic 
inbound from clients to web apps hosted on these servers and know that traffic 
is going to the correct NIC.
**Outbound traffic on the NLB NIC is not recorded. This holds true whether the 
capture is in promiscuous mode or not.**
Inbound and outbound traffic are recorded normally on the dedicated NIC for 
each server as they communicate with each other behind the firewall.
On the client side, a corresponding packet capture shows that clients see 
server traffic from the NLB IP address just fine.
>From the firewall, I see inbound and outbound communication from each server's 
>NLB NIC, which further suggests that traffic is passing normally.
My web apps work normally, and affinity is being maintained.

These observations hold true whether I am using Wireshark or WinDump, which is 
why I am asking the WinPcap group.

My environment:

WinPcap 4.1.2, as bundled with Wireshark 1.8.3
Cisco ASA 5505 (meh, it's a lab.)
4 HP ProLiant servers
HP NC326i dual port adapter (Broadcom), tested driver versions are 14.2.0.5 
from 2010 and 15.2.0.8 from 2012.
Both a dedicated NIC and a clustered NIC are configured.
NLB has the following attributes:
*       Four servers converged
*       Unicast mode
*       Port rules defined for 80 and 443
*       Multi host with Single affinity

I searched known bugs / issues and probably missed a checkbox somewhere or 
something. Any thoughts? Multicast deal?

Thanks,

James


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