Comment 16 for bug 314713

I've had similar problems, as far as I can tell it's due to the following rule in the router's firewall config

TCPMSS tcp -- anywhere anywhere tcp flags:SYN,RST/SYN TCPMSS set 1360

I've had problems with this rule before, using a WiFi card with a small MTU. It was actually increasing the MSS and making it too big for the MTU. I'm sure the intention of the rule is to decrease the MSS only.

Removing the rule with iptables -D fixes the LinkedIn problem. So far it doesn't seem to have broken anything else. Note that the rule will come back if the router is rebooted.