LACP vs HA

[KyleHB]

Hi guys,

I'm new here and new to network as well. I have a simple question.

Is LACP/PAGP different from High Availability or Chassis Cluster (for JunOS)?

I understand that LACP logically combines 2 or more (up to 8) interfaces into one, having a faster throughput. Isn't that what HA does as well?

Thanks in advance!

[Georg Pauwen]

Hello,

PAgP (Cisco proprietary) and LACP combine several layer 2 links for higher throughput. Juniper Jun OS does not have (at least to my best knowledge) a proprietary link aggregation protocol, so it uses LACP as well. Juniper HA clusters are more a hardware/software based redundancy solution, so it has nothing to do with LACP.

Below, FYI, a good explanation of link aggregation in Cisco equipment:

PAgP is a Cisco-proprietary protocol that you can only run on Cisco switches
and on those switches that licensed vendors license to support PAgP.
IEEE 802.3ad defines LACP. LACP allows Cisco switches to manage Ethernet
channels between switches that conform to the 802.3ad protocol.
You can configure up to 16 ports to form a channel.
Eight of the ports are in active mode and the other eight are in standby mode.
When any of the active ports fail, a standby port becomes active.
Standby mode works only for LACP, not for PAgP.

[Joseph W. Doherty]

Bundling links can be a part of HA. However, as you note, bundling link may also increase aggregate throughput. (BTW bundling links does not guarantee an increase in throughput, however it's more likely to guarantee helping to contribute HA.)

A Juniper chassis cluster can be another HA contributor, such as can Cisco's fabric, VSS or StackWise technologies. Such technologies might also improve throughput.