Black Box TS250A, Manual, Page: 53 / 64

Can I “team” NICs in my analyzer?
Chapter 5 FAQ and Troubleshooting
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transmission unit), the receiving device could restart the negotiation
process. For more details, see
“Not seeing traffic at the analyzer from
the TAP” on page 56.
If you are attempting to daisy chain Aggregator TAPs to more than
two analyzers and you are certain your MTU on the receiving devices
is high enough, contact Black Box Support for assistance.
Can I “team” NICs in my analyzer?
Yes, it is possible, with some caveats.
Sometimes it is desirable to use two standard full-duplex NICs to
capture full-duplex TAP output for analysis. Because a standard NIC
port has only one receive channel, you must aggregate the receive
channels from two ports to see both sides of the two-way connection
being monitored. Intel’s Advanced Network Services allows you to
team multiple connections at the driver level, presenting your
analyzer with an aggregated view of send and receive channels.
Because of the processing overhead and its affect on NIC
performance, this method is not recommended for monitoring
moderate to highly saturated links, such as those between switches.
However, it can be an economical alternative when monitoring more
lightly used connections, such as between a server and switch.
In addition to the bandwidth limitations, connection teaming is also
less accurate when timestamping packets, which can cause
unexpected results when your analyzer attempts to display certain
charts and statistics such as Connection Dynamics or VoIP jitter. You
also will not be able to tell which side is DCE vs. DTE. In short, if you
do not have a dual-receive analysis NIC, it is always better to analyze
the SPAN or port mirror session through a standard NIC rather than
using the connection teaming method described here.