Bypass FAQs

Ixia Bypass Switches are inline devices that provide fail-safe protection for inline security and monitoring devices.

Here are some frequently asked questions and answers to help you choose the right iBypass switch for your particular deployment.

General Questions on Bypass Switches

Q: Which iBypass switches can be used for copper (up to 1G speeds) and what are the maximum number of links that can be protected by each model?

A: There are three different models:

I3BP-CU3 – This protects a single copper link (up to 1Gbps)

iBypass HD (IBP-8000) - This is a modular system which can house up to 4 modules. Each copper module (DBM-100) can support up to 2 copper links, so protecting a maximum of 8 copper links.

iBypass VHD - This is a modular system which can house up to 3 modules. Each module (IM-21-BYP) can support up to 4 copper links using SFP transceivers, so protecting up to 12 copper links.

Q: When is an iBypass switch in “ON” state?

A: The bypass switch will be in Bypass State “On” when any of the below events occurs:

• Power loss from the bypass switch

• Monitor Link failure – either one of, or both, the monitor ports 1 and 2 links down

• IPS application failure (can be caused by loss of power to the IPS or not passing Heartbeat packets)

• Bypass On mode is forced administratively

Q: When is an iBypass switch in “OFF” state?

A: The bypass switch will be in Bypass State “Off” when ALL conditions below are met:

• Bypass switch is in power on

• Monitor Ports 1 and 2 are in link up state

• IPS application is running (passing Heartbeat packets)

• Bypass On mode is not administratively forced

Q: What are the typical bypass modes?

1.       Bypass-Fail-Open is when the bypass switch is in normal bypass operation with fail open functionality. “Fail-Open” allows Network Ports A and B to stay link up and pass traffic between them directly (monitor ports are "bypassed") when bypass switch is in Bypass “On” state

2.       Bypass-Fail-Close is when the bypass switch is in normal bypass operation with fail close functionality. “Fail-Close” forces Network Ports A and B to be in link down, therefore no traffic between network ports A and B, when bypass switch is in Bypass “On” state.

3.       Force-Bypass-On-Fail Open is when the bypass switch is forced into Bypass On state with fail open functionality – network ports A and B are still link up, thus allowing network ports A and B traffic flow (Tool maintenance for example)

4.       Force-Bypass-On-Fail Close is when the bypass switch is forced into Bypass On state with fail close functionality – network ports A and B are forced to link down, no traffic flow at all.

5.       Force-Bypass-Off is when the bypass switch is forced into Bypass Off state.

6.       Tap is when the switch becomes a half-duplex breakout Tap, bridging network traffic between network port A and network port B, while mirroring traffic entering network port A to monitor port 1 and traffic entering network port B traffic to monitor port 2.