I have an ASA firewall in production. When I issue the show interface command, there are lots of underruns and it keeps increasing. I have change the LAN cable, reset the interface, enable and disable flow control and even changed the device connected to that interface. Has anyone experienced this? Any suggestions?
as stated in https://supportforums.cisco.com/discussion/10780211/help-underrun-errors : underruns occours when rx-ring is full (unable to accept more pkts); it mean that NIC is unable to pass data to IP level at same speed they arrive at NIC.