HPE 1920S 24Ports 802.3ad Layer 2+3 (MAC+IP) possible

[Chris30]

Hello,

I'm using a QNAP TS-451+ with 802.3ad Prorttrunking with the hash policy Layer 2 MAC.

QNAP suggests to use the hash policy Layer 2+3 MAC and IP, does this Switch support this?

Thanks in advance

Chris

[parnassus]

You should use the Hash policy that better fits the egress traffic your QNAP/Switch has in order to achieve a good sessions distribution along all LAG member links (using Layer 2, 3 or 4...each one falls to the lower level if egressing packets don't own L4, L3 and L2 data to process during and for hash calculations)...I mean with "better fits" I mean that that particular hashing method (on egressing packets) distributes outgoing traffic better.

LACP Hashing algorithms used on peer LAGs don't necessarily need to match each others...indeed each LAG (LACP or Static) processes its own outgoing traffic using its own selected hashing algorithm for egressing packets to use all available links (consider that there will be cases that will produce polarizations)....and each LAG acts unaware of what the other end does on its outgoing traffic...each link aggregation has no power on incoming traffic (ingress)...in other term it can't drive which LAG member link an incoming session is going to use.

With regard to what hashing the 1920S supports, documentation reports:

The hashing algorithm used to distribute traffic load among the physical ports of the trunk while preserving the per-flow packet order. The hashing algorithm uses various packet attributes to determine the outgoing physical port.
The following sets of packet attributes can be used to compute the hashing algorithm:

- Source MAC, VLAN, EtherType, Incoming Port
- Destination MAC, VLAN, EtherType, Incoming Port
- Source/Destination MAC, VLAN, EtherType, Incoming Port (This is the default selection)
- Source IP and Source TCP/UDP Port Fields
- Destination IP and Destination TCP/UDP Port Fields
- Source/Destination IP and TCP/UDP Port Fields

So it suppprts up to Layer 4 (src/dst IP addresses + TCP/UDP Port fields).