It seems like sometimes there are some connectivity problems around the edge of our network to certain other networks, and my ssh sessions with some remote servers, which themselves have no connectivity issues, drop.
Remotely, the sessions still appear as active; locally, I have optimised Windows 7 TCP for PuTTY to not drop connections on brief outages (with anything below 7 minutes being brief, and our edge connectivity issues probably last at most around 1 or 2 minutes), so, I'm thinking there's probably some reply packet that some edge equipment generates for my ssh client to keep dropping the connection during such otherwise-unnoticeable and very brief connectivity issues. RST, maybe? There's no NAT. This issue happens most often over IPv6 (that's what I mostly use), but I think IPv4 may also affected (did my TcpMaxDataRetransmissions fix not apply to IPv6?); the whole network is GigE and above.
What's the packet?
Would it be safe to ignore it? (for ssh)
Unless there's a simple OS setting for this, I plan on ignoring it with pf(4) around my network segment.