im getting "Authentication failed. Error code: Forbidden" while loggin in catlight

To enable anonymous access, you can go to "manage Jenkins" / "Configure global security" page, and then check "Allow anonymous read access"

tomcat server 

im able to login using user's of jenkins but issue with anonymous user

for this do i need to do any settings in jenkins to allow anonymous users

What type of server do you have and what type of authentication do you use?

This error can also be returned by a proxy server. If proxy server requires authentication, you can configure it in edit/settings/proxy.