I am getting input and CRC errors on the WAN interface of my Cisco router.
I have tried several Cisco routers - (3) 1841's, and now a 2801.
I've replaced all cabling. The Internet connection (cable) has been changed from coax (30x5 - replaced the modem 3 times as well), to fiber at 50x50.
We've worked with ISP and changed speed/duplex to different values - both auto and "locked" to matching values.
Any possibility the 10/100 interfaces on the 1841/2801 are having issues with the Gbe links on all sides? The inside interface is connected to either a Gbe switch, or to the Gbe port on the Barracuda and does not report input errors.
Additionally, with 50x50 service, and a single laptop connected to the inside interface of the 1841/2801, I can only pull about 20x50. If I bypass the Cisco and connect directly to the ISP gear, I can pull the full bandwidth (50x50).
One last nugget of information - this interface (fa0/1) is connected to the cable ISP, but we are using BGP and a GRE tunnel to route IP space from ISP #2, which is also connected to this router with a T1 WIC. No NAT'ing is performed on this router - ALL IP's are public IP's.