Frequently Asked Questions - 10/100 Tap
- Does the SharkTap respond to flow control packets?
- No, the SharkTap doesn't respond to any packets, it only passes them through. Flow control, or VLAN packets, or any other special purpose packets that might be intercepted by a smart switch, are simply passed through and mirrored to the tap port.
- Will the SharkTap "fail open"?
- No, the 10/100 SharkTap won't affect the link under any normal circumstances, including loss of power. The SharkTap uses a capacitively coupled passive monitoring architecture, so the two NETWORK ports are hard-wired to each other. The SharkTap is merely a patch cable in that sense. There is of course a slight load on the line, about 3000 ohms (which, for context, is about 30 times the required termination resistance of 100 ohms)
- Is the SharkTap an aggregate tap?
- Yes, the SharkTap will 'aggregate' packets from the two NETWORK ports and mirror (i.e. duplicate) them on the tap port. If two packets are received at the same time they will be duplicated sequentially on the tap port. The SharkTap has a large 64KB buffer to absorb bursts of full duplex traffic.
- Does the SharkTap support Power over Ethernet?
- Yes, but the 10/100 Tap only passes pins 1,2 and 3,6. These pins are hardwired between the two NETWORK ports, so any PoE is hardwired as well.
- Does the SharkTap support gigabit ethernet?
- No, not this model. The 10/100 Tap only passes pin pairs 1,2 and 3,6 so a gigabit PHY will auto-configure at 100Mpbs (see "HELP!" below, though) and will work fine, just at a maximum of 100Mbps. The 10/100/1G and USB models fully support gigabit speeds.
- Can the SharkTap drop packets?
- Yes, but only on the TAP port. Traffic will never be affected on the NETWORK ports. The SharkTap has fairly large data buffering, but if the sustained, combined data rate of send + receive data is greater than 100Mbps, the SharkTap will not be able to duplicate all packets to the TAP port, so some packets can be dropped. This is actually pretty rare in real world connections, but it can happen.
- HELP! The Tap is not showing ANY packets!
- There is an occasional problem where this passive tap will interpret a link as 10Base-T when it's really 100Mbps. If you see the green LED only, on one or both Network ports but you know the link is 100Mbps, you probably have this problem.
- The problem most often shows up with ports that are gigabit ports but come up in 100Mbps because only two pairs are passed through the tap. Try forcing the ports to 100Mbps from the operating system.
- There actually is not an IEEE standard for a gigabit port run over only two pairs, so not all ports will fall back to a true 100Base-T.
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