I have a Synology NAS (DS1813+) that is seeing a significant number of errors on the eth0 interface. Strangely Dropped and overruns are always exactly the same.

Example
+++++++++++++++++++++++++++++++++++++++++++++++
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:24565747 errors:0 dropped:73295 overruns:73295 frame:0
TX packets:22157269 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:23025883380 (21.4 GiB) TX bytes:30893815725 (28.7 GiB)
+++++++++++++++++++++++++++++++++++++++++++++++

I get a few RX errors if I just copy to NAS
I get no RX errors if I copy from the NAS
I get TONS of RX errors if I copy to/from NAS simultaneously
I never get TX errors.

I tried different network cables, switch ports, interfaces on the NAS, nothing seemed to make a difference.

I never get any dropped packets listed in winbox when viewing the Ethernet port the NAS is on. I assume that is because its not dropping in the switch.

Possible solution
turn RX flow control on for the interface the NAS is plugged into. It really does appear to work. The NAS does not seem to increment errors, and the switch increments RX pauses.

My question is
Call it a day and close the issue, or continue to look into it. Seems to me that the synology should be fast enough to handle a single gig link, heck it comes with FOUR interfaces!!!

In the realm of storage, flow control is an extremely useful feature and is commonly used in large Data Centers to keep the flow of traffic over the ethernet connections at roughly the same rate as the disk can read/write.

Typically the disk speed or the SAN controller becomes a bottle neck long before the network connections fill up....this is true even on Fiber Channel SANs with multiple 10 Gbps links.

OK. I put all 24 GiGE ports and even the 10GigE SFP+ to Auto TX/RX flow control on my CCS226. I will watch for a while see how things go. Now I just need to find out how to find dropped packet stats on a windows box .....