Before, NE40 work normally, I can login normally. the customer powered off this NE and moved this NE to another site,and change one LPU board from one slot to other slot, after power on again. When I try to login to NE40 there are error that User name of pasword is wrong. version VRP 3.10 2358;
In startup I have enter to boot manu then enter to hiden manu ,from hiden manu chose erase flash. Then reboot the system. After startup I can login to NE40 but configuration is lost after this. Just like new NE40.
I have analysis it in two case.
1.Router was power off and did not change any thing.
2.Router was power off and after this some board was changed.
In both of case router is start up and from indicator on the boards I can see that it is working normal.
But in second case I can not login to system. looks like user name of password is changed , But in fact we didn't change usename and password.In first case every thing is normal and I can login to system.
Also after facing second case you can not login even if you changed back all board to original position. So this problem was caused by second case.
Don't change hardware configuratin during power off status,and before shutdown the device ,Need get backup from configuration .