[adient]

You may have tried but generally add -n to netstat to speed it up by just displaying IPs instead of trying to resolve them. I've never seen a system with so many concurrent connections hands on so there could be some other bottleneck.

[jen_h]

netstat -s |grep "connections established" is pretty fast and does the job if you're not filtering for certain ports or IPs. But running plain old netstat on a system with so many connections is a really bad idea. I almost fired myself once over a crufty cron job I left running...