Please can anyone help with this problem: I accidentally erase the flash on cisco 871 router, though I have a back for the ios but I have not been able to restore it back because the router has no ip address. Have tried restoring with tftp server but without ip address given to router the tftp server can't reach the router. Please this is urgent because the router is being used in my office and I need to get it up and running ASAP. Possibly within the hour. Thanks in anticipation

Please can anyone help with this problem...

Connect to the router via the serial console port (serial to RJ45 cable required, came with router), set an IP address, and copy the backup from the TFTP server. Refer to Restore the Cisco IOS to a router (http://articles.techrepublic.com.com/5100-10878_11-5623025.html) or Cisco's website for recovery information for the 871. The exact procedure may be router model dependent.

Also, I'm curious as I've seen several posts here regarding accidental IOS erasure, how does one "accidently" erase the IOS?