Good thought on duplex, but thats not it. Duplex for PC and Router are Full (100mb/s). I thought keepalive because it seems to drop if I am inactive on the console for a period of time. To be honest, I am not exactly sure what keepalive does. I have seen many people on the forum disable it.
Keep in mind I never actually lose connection (if I didnt look at the log I wouldnt know anything had happened). It just bothers me.
Below is all I got for the error description.
If your configurations all works out, then I'm thinking an incompatible NIC - it happens.
Cisco Error Decoder
1. %PKT_INFRA-LINEPROTO-5-UPDOWN Line protocol on Interface [chars], changed state to [chars]
The data link level line protocol changed state.
Recommended Action: If the state change was unexpected, confirm the configuration settings for the interface and line protocol.
Related documents- No specific documents apply to this error message.
Just grasping at straws here. If the line protcol on the router is bouncing then it's possibe that the switch the router is connected has a problem.
Does show interface display any other errors?
If you are using a crossover cable then maybe the NIC on the PC is going into some kind of power saver mode?