"show interface" Cisco Router?
when i enter command "show interface" on cisco router it gives "1246 input errors, 828 CRC, 417 frame, 0 overrun" how and why these errors are generated and what are the cause of it. kindly explain
Answers:
Going off of the information in your question, I would bet a dime to a dollar you have a single ethernet port on your router. You are seeing the current stats of that interface. You have 1246 errors from the device connected to the port, 828 frames were viewed as CRC or "Cyclic Redunduncy Check Errors" which means the size of the frame the router saw did not match what the size of the header inside the frame says the size would be, in numbers of bytes, so the router calls it a CRC frame and discards it. Frame errors are general, can be from a device firt coming up and negotiating to 10 or 100Mb/s, a bad cable, bad NIC card if running to something like a server, or possible hardware problem if this port services a switch or hub. Good news is this is a reasonably small amount of errors and I would not suspect a problem unless this accounted for 100% of the data recieved at this port. Usually you don't have a probelm until errors become more than 10% of the total traffic, but even 5% is unusual in a switched environment. Before these messages, it should say someting that idetifies which port it is informing you about, such as EN0 or E0. Or if this where a serial port it may be called S0. All depends on what hardware and how many interfaces you have. You can get more specific info by typing "sho int ENO" or more correctly "sho int (whatever port you want)". This will return more precise info such as total packets in and out and the speed, utilization, etc. To see what interfaces exist, type "sho run" and read the description of all interfaces available. In any case, this sounds like a normal functioning router port. If info is scrolling by before ou can read it type "term length 25" and you should stop at each full page in a windows telnet session box or direct cable connect. Good Luck.
Other answers:
It all depends on the number of 'input packets' you see on the interface.
If the percentage of errors is below 0.1%, I wouldn't worry about it.