What's constitute an entry on the IPTables and how to find out which client it is originated from

Posted by cbd on Server Fault See other posts from Server Fault or by cbd
Published on 2012-10-05T02:55:50Z Indexed on 2012/10/05 3:40 UTC
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iptables

I have a Billion BiPac 7700N Modem/Router/Access Point and I connect another router (TP-Link TL-WR1043ND) in wan-bypass mode to extend the wireless coverage. Lately, I noticed that the connection through TP-Link has been dropping out quite regularly.

Having read some posts on the Internet, I checked system log on 7700N and found that there are many "nf_conntract: expectation table full" errors, which I suppose the iptables are full.

My questions:

What does constitute an entry on the iptable? Is it a client or a connection (which means one client can have multiple connections)
How could I find out where are those connections originated from?

Note: Many reported that the issue is usually related to having torrents running but I don't have any torrents running.

Thank you.

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