Posted on January 13, 2020 4:59 pm
 |  Asked by Damiano Lama
Print Friendly, PDF & Email

Hi Support,
something is getting me confused on the difference between TAP and TOOL ports. Said that Tap ports are ports that receive traffic exchanged between 2 network ports and that Tap ports prohibit egress traffic, and said that Tool ports replicate traffic to a device analyzer, I see a lot of forums online that say that in the EOS 4.13.1F Tap ports are send only and Tool ports are receive only. This is getting me confused, so Tap ports are send or receive ports?
As per my undesrtanding Tap ports only receive traffic so they should be only receive ports.

Thank you for your clarification on this topic.


Posted by Alla Anunitya
Answered on January 20, 2020 5:22 pm

Hi Damiano,

Your understanding of the tap and tool ports are correct. The functionality of the tap port is to receive traffic from a device usually in the production network and egress it out of the respective number of tool ports attached to the monitoring tool. Hence, tap ports are receive-only(Rx) and tool ports are send-only(Tx).

Packet flow:
Production Network ------->Tap(RX)[Arista TapAgg Switch]Tool(Tx)------> Monitoring Tool


Posted by Victor
Answered on January 21, 2020 1:02 am

Hello Damiano,

While in tap aggregation mode, there is support for traffic only in one direction through either tap ports
that receive packets from mirroring or Span ports and optical tap or Tool ports, that send out packets
to customer devices (traffic analyzers, packet capture tool, sniffers, IDS/IPS, firewall)

Two-way ports for tap aggregation allows bidirectional tx and rx capability on a
single port in Tap Aggregation mode. Using the tap-tool switchport mode enables both tap and tool
configurations simultaneously on an interface.

The following platforms support two-way ports for tap aggregation.
• DCS-7280R
• DCS-7280R2
• DCS-7500R
• DCS-7500R2

For more information about Tap Aggregation you can refer to the following article:

Let me know if this answers your question.


Post your Answer

You must be logged in to post an answer.