Open your Backtrack terminal and Type xhydra and press enter
In the target tab, select
Single Target: 192.168.1.1
Protocol: http-get
Single Target: 192.168.1.1
Protocol: http-get
In passwords tab, select
username: admin (because most of the routers have default username as admin)
In the passwords, select the password list option and browse to select your passwords file. Here I have used my custom password file.
In Specific tab select
http/https URL: http://192.168.1.1/
Now select start tab and click on start button, the password cracking begins and result is as follows
Open the browser and type http://192.168.1.1/
Put the password u got from xhydraand get administrative access to the router