How I took the access control on companies internal network?

Once more 
Bypassed an internal network login panel 
Not even thought that organisations are not focussing on their networks and using this type of low security for their internal networks.

I’ll not reveal the name so assume it as ABC solutions
I went on the client’s side and connected their Wi-Fi in my laptop and browsed their gateway IP which was obviously 192.168.x.x
I saw a login panel and it’s of Cisco 
I simply gave it a thought and searched for default password for the panel and found as uname-Cisco and pass-Cisco and tried those. 
Results was not expected that I got access to their internal server. 
1)Always customise the URLs 
2)Go for passwords other than defaults 
3)Try to go apply passwords with encrypted values.