repomd.xml is unsigned

Attempting to install apache2 … first up get the warning that the master index file is unsigned and may no longer be trustworthy??

(10:19 root@fssd-OS422 /) > zypper in apache2

Retrieving repository 'Main Update Repository' metadata -----------------------------------------------------------------------------------------------------------------------------------------------------|]
Warning: File 'repomd.xml' from repository 'Main Update Repository' is unsigned.                                                                                                                                
                                                                                                                                                                                                                
    Note: Signing data enables the recipient to verify that no modifications occurred after the data                                                                                                            
    were signed. Accepting data with no, wrong or unknown signature can lead to a corrupted system                                                                                                              
    and in extreme cases even to a system compromise.                                                                                                                                                           
                                                                                                                                                                                                                
    Note: File 'repomd.xml' is the repositories master index file. It ensures the integrity of the                                                                                                              
    whole repo.                                                                                                                                                                                                 
                                                                                                                                                                                                                
    Warning: We can't verify that no one meddled with this file, so it might not be trustworthy                                                                                                                 
    anymore! You should not continue unless you know it's safe.                                                                                                                                                 
                                                                                                                                                                                                                
File 'repomd.xml' from repository 'Main Update Repository' is unsigned, continue? [yes/no] (no): 
                                                                                                            

Should i treat this waring seriously?? … or ignore it?

Thanks

and on answering ‘no’ i get this:

File 'repomd.xml' from repository 'Main Update Repository' is unsigned, continue? [yes/no] (no): Retrieving repository 'Main Update Repository' metadata .................................................................................................................................................[error]
Repository 'Main Update Repository' is invalid.                                                                                                                                                                 
[download.opensuse.org-oss_1|http://download.opensuse.org/update/leap/42.3/oss] Valid metadata not found at specified URL                                                                                       
Please check if the URIs defined for this repository are pointing to a valid repository.                                                                                                                        
Warning: Skipping repository 'Main Update Repository' because of the above error.                                                                                                                               
Retrieving repository 'openSUSE:Leap:42.3:Update' metadata --------------------------------------------------------------------------------------------------------------------------------------------------|]
Timeout exceeded when accessing 'http://download.opensuse.org/update/leap/42.3/oss/repodata/repomd.xml'.                                                                                                        
Abort, retry, ignore? [a/r/i] (r): 

Could this be problems at my end?? or is it something out of my control?

Thanks again…

http://files.zimpics.org/forum/suseRepoInstallApache2pnghttp://files.zimpics.org/forum/suse/RepoInstallApache2.png