WLC 5520 cannot automatically jump out of the portal page

[Translator]

Ladies and gentlemen
I've got a problem here. For unknown reasons, the controller is 5520 while it's version  is 8.1.123, and it's an old device.

Recently, I found that the portal authentication we did ourselves cannot automatically jump after linking the SSID. After checking several times to confirm that the configuration is correct, we found that a problem - the virtual ip of the device itself is set to 1.1.1.1, which is not recommended by Cisco. I've seen a suggested change in below document, otherwise it will affect the redirect authentication. 

https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/213535-wlc-virtual-ip-address-1-1-1-1.html

And then I found that if I linked SSID,  Manually entering 1.1.1.1 on the browser, it will automatically enter Cisco's authentication interface, when I click to confirm, it will jump to my preset portal page.

Have any experts ever encountered this? I would appreciate your help on this.
Thank you!

[Flavio Miranda]

Hi

 I had many WLC with this IP in the past and it worked but I  agree that this is not good as 1.1.1.1 is a valid IP address.  What you can do is change change it in the virtual interface. Now a days cisco recommend to use 192.0.2.1.

You need to reload the WLC in order this change to take effect.

[Rich R]

That code version is ancient!  Update code https://www.cisco.com/c/en/us/support/docs/wireless/wireless-lan-controller-software/200046-tac-recommended-aireos.html#anc10

Regarding virtual IP: https://www.cisco.com/c/en/us/support/docs/wireless-mobility/wireless-lan-wlan/213535-wlc-virtual-ip-address-1-1-1-1.html

OR use a valid, registered public IP which you own, with corresponding DNS resolvable domain name which matches your certificate issued by a public certificate authority.  This is the most compatible option as OS and browser security standards are constantly becoming more restrictive.