LACP Trunk on Aruba with QNAP not working on Outgoing Traffic

[eternityseeker]

I have a 2530 Aruba Switch with 4 ports as LACP trunk connected to QNAP with 4 NICs configured as a 802.3ad dynamic trunk When 2 clients try to write or copy a file to the QNAP each one gets 100 MB/s speed so the aggregation is working and i can see in QNAP resource monitor that two NICs are utilized. But when both clients try to copy from the QNAP, then only one NIC is used and both clients are copying data at 50 MB/s.

Is there anything that could cause such behavior? copying to QNAP is fast and using aggregation but copying from QNAP is not?

- Incoming Traffic to QNAP is distributed across more than one NIC (LACP Works) - Outgoing Traffic to QNAP only uses one NIC at all times (LACP not working)

- "cat /proc/net/bonding/bond0" Shows:
<pre>
Bonding Mode: IEEE 802.3ad Dynamic link aggregation
Transmit Hash Policy: layer2+3 (2)
MII Status: up
MII Polling Interval (ms): 100
Up Delay (ms): 0
Down Delay (ms): 0

802.3ad info
LACP rate: slow
Min links: 0
Aggregator selection policy (ad_select): stable

Slave Interface: eth2
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 3
Permanent HW addr: 24:5e:be:27:e1:2b
Slave queue ID: 0
Aggregator ID: 4
Actor Churn State: none
Partner Churn State: none
Actor Churned Count: 1
Partner Churned Count: 1

Slave Interface: eth3
MII Status: up
Speed: 1000 Mbps
Duplex: full
Link Failure Count: 3
Permanent HW addr: 24:5e:be:27:e1:2c
Slave queue ID: 0
Aggregator ID: 4
Actor Churn State: none
Partner Churn State: none
Actor Churned Count: 0
Partner Churned Count: 1

</pre>

[parnassus]

There is an essential (and basic) consideration you need to do with regard to how (and what) traffic is distributed on aggregated links: LACP distributes - using the configured hashing algorithm on each peer - egress traffic...so traffic which is leaving your NAS and tihe one which is leaving your Switch...depending on involved Source/Destination IP/MAC Addresses...these sessions distribution can suffer of polarization (they are "biased") and one link or two links on each group could manage more sessions than the others...in other terms simply having many physical links aggregated together doesn't automatically (and always) mean that those links will be equally used in any possible situation (so the distribution of egress sessions is well balanced)...there could be corner cases.

[parnassus]

You cited four (4) ports LACP aggregated on both sides (Aruba 2530 Switchand QNAP NAS): why the NAS bond0 reports only two interfaces instead of four (as expected)? Can you also show us sanitized outputs of show trunks and show lacp commands executed on Aruba 2530 of involved trunk?