I'm having an issue with file transfers between two sites across a 1Gbps Site-to-Site IPsec VPN. If I initiate a file transfer from a node in Site 1 that is connected to the network at 10Gb, I get about 1/3 the speed compared to transfers from clients connected at 1Gbps. This is only an issue across the VPN as connections between 10Gb and 1Gb nodes on the LAN are at line speed. It also only happens when going from Site 1 to Site 2. Site 2 to Site 1 has no issues. However, Site 2 has no node connected at 10Gb.
I've done a packet capture when doing one of these transfers from a 10Gb node in Site 1 to Site 2. I'm seeing dropped packets, lots of TCP re-transmissions, and the TCP window size remains small since the TCP protocol is clearly not reading the connection as "smooth." The question is...Why?
** FYI it's not an MTU or QoS issue as I'm using standard MTU (no jumbo packets anywhere) on all devices/NICs along the path and no QoS is configured.
No comments:
Post a Comment