On 6/22/2020 2:31 PM, Trampas Stern
wrote:
I got a wireshark dump from customer and it looks like there is a lot of ARP messages on their network.
Does the ARP broadcast consume a connection?
No. ARPs do not consume a [TCP] connection.
In the image below our device is 10.2.65.250 and it is looking like we are getting duplicate requests (line 116,129) from the client.
It looks like packet 116 is a resend of packet 115, and then packet 117 is the ACK for packet 116.
Packet 129 is a resend of packet 112, and then packet 130 is the SYN-ACK for that [second] connection.
In both cases, your device seems to be losing a packet and recovering after the resend?
How many simultaneous connections does your device support?
The network has lots of ARP requests...
It appears that a device is asking for 10.2.65.1, which might be a mistake as the gateway is 10.2.64.1 with netmask of 255.255.254.0
Do you have any idea what devices have the "MRVCommu" OUI in their MAC addresses? Maybe those devices are misconfigured?
I am wondering if the ARP traffic is overwhelming lwip...
I haven't had a chance to review the ARP code to see if getting overwhelmed would affect the TCP connections? Regardless, there doesn't appear to be a high enough rate of ARPs to be troublesome. Many of them are 1 second or more apart.
Please share any other clues and maybe we can find something...
Patrick