Static LAG between GS116Ev2 and Synology

[Mic-cosmos]

Hi,

I have a GS116Ev2 which is attached to a Synology DS1815+ via two cat5e/6 cables. I have tried setting up static LAG between the two but have had some interesting results that I am hoping someone could clarify for me.

Test Setup:

-GS116Ev2 attached to Synology via two cat5e/6 cables.

-Two Mac clients on individual 1gigabit ethernet connections attached to the same GS116Ev2 with RAMdisks setup for testing to eliminate drive-writing speed as an issue.

-Multi-gig files pulled from Synology via AFP to each of the two Mac clients

Settings & Results:

1) Per Netgear KB instructions at https://kb.netgear.com/000053558/How-do-I-set-up-a-static-LAG-between-a-Smart-Managed-Plus-Switch-an..., GS116Ev2 (LAG enabled), Synology (balance XOR enabled), Synology DSM showing 2000Mbps link, ~112MB/s=1Gb throughput, LAG doesn't work.

2) GS116Ev2 (LAG disabled), Synology (adoptive load balancing enabled) - ~160MB/s>1Gb throughput, LAG works.

Questions:

1) Why is this the case? Can someone at Netgear verify that balance XOR doesn't work with static LAG on this switch?

2) Given that ALB works, is there any advantage to balance XOR over ALB?

[schumaku · Accepted solution]

Always the same, it's one of the most asked question in NAS communities:

---

@Mic-cosmos wrote:

...GS116Ev2 (LAG enabled), Synology (balance XOR enabled), Synology DSM showing 2000Mbps link, ~112MB/s=1Gb throughput, LAG doesn't work. ...

---

It's not that it does not work - it does not behave the way you expect, and the indication of beeing a 2000Mbps link is misleading (Syno is in good company, Intel did the same nonsense on their Windows systems bonding divers), worse, it's complete nonsense. This must be written my marketing people...

This is because these switches are plain L2 devices, these automatically record the mapping between MAC addresses and port.By default, each MAC address can only be mapped to one port at a time. In Balance-XOR (Linux bonding driver mode 2), all NICs under the created bond interface share the same single MAC address.

In reality, only Active-Backup (mode 1 - just fault tolerance), Balance-TLB and Balace-ALB (mode 5 or 6) can be used to gain a througput advantege for your use case.

Preferred is always deploying switches supporting 802.3ad (mode 4).

[schumaku · Accepted solution]

Always the same, it's one of the most asked question in NAS communities:

---

@Mic-cosmos wrote:

...GS116Ev2 (LAG enabled), Synology (balance XOR enabled), Synology DSM showing 2000Mbps link, ~112MB/s=1Gb throughput, LAG doesn't work. ...

---

It's not that it does not work - it does not behave the way you expect, and the indication of beeing a 2000Mbps link is misleading (Syno is in good company, Intel did the same nonsense on their Windows systems bonding divers), worse, it's complete nonsense. This must be written my marketing people...

This is because these switches are plain L2 devices, these automatically record the mapping between MAC addresses and port.By default, each MAC address can only be mapped to one port at a time. In Balance-XOR (Linux bonding driver mode 2), all NICs under the created bond interface share the same single MAC address.

In reality, only Active-Backup (mode 1 - just fault tolerance), Balance-TLB and Balace-ALB (mode 5 or 6) can be used to gain a througput advantege for your use case.

Preferred is always deploying switches supporting 802.3ad (mode 4).