The packet capture looks the same doing it this way. So I've also tried connecting to laptops directly into the service providers equipment at both sites, and putting them on the same subnet. Since it is a metro ethernet circuit, no router is required. The packet capture with it installed had the same results. Since this started, I've replaced the sonicwall with an 1800 cisco router.

TX packets:149148 errors:0 dropped:0 overruns:0 carrier:0 RX packets:244994 errors:0 dropped:0 overruns:0 frame:0 UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1 Here is a traceroute from my system to the server (ping times are usually steady under 10ms): ifconfig eth0Įth0 Link encap:Ethernet HWaddr 00:e0:b8:c8:0c:7e Here is a screenshot from wireshark, and here is the entire capture. The two sites are connected by one sonicwall router, so the sites are only one hop away. '5','0.076967','200.121.1.131','172.16.0.I'm getting excessive TCP Dup ACK and TCP Fast Retransmission on our network when I transfer files over the MetroEthernet link. Here is a concrete examples of gathering frequencies, I chose to measure how many times an IP was a source and how many times it was a destination.

Tcp spurious retransmission wireshark