📡 When Your Main Hub Cannot Reach A Linked Site

Normally your main Hub reads each linked site. Some sites sit behind a firewall, a security plugin or a security service that turns the main site's request away before WordPress ever sees it. When that happens, the main Hub says Could not read it, with the reason in plain words. You can either allow the request on that site, or turn the link around so the other site sends its numbers instead.

Where to see it:

• On your main site, Settings, Linked sites lists each linked site. One that cannot be read shows Could not read it in red, with the reason, and a line pointing you to the send code
• On your main Overview, that site's block says Could not read, the site's address and the same reason

Reading the reason:

The Hub tells you what refused the request. The most common answers and what to do:

• It took too long to answer: nothing to do, it is tried again at the next refresh
• Could not reach it: check the site is up and the address is right
• Its security certificate was refused: check the site opens over https
• The ResultsAiX Hub there is older than 1.0.43, or switched off: update or switch on the Hub on that site
• It answered, but not with Hub numbers: a caching or security plugin on that site may be changing the answer
• The security service in front of that site (its CDN firewall) blocked the request: check that service's firewall rules and IP access rules, and allow the address the message names
• That site's server firewall blocked the request: ask the host to allow it
• A security plugin on that site blocked the request: allow it in that plugin's blocking settings
• Something in front of WordPress on that site refused the request: the Hub gives the error number, the server name that answered and the address to allow
• That site answered with a server error: try again shortly, and check its error log if it keeps happening

The address to allow is always the Hub's read address on that site, ?rest_route=/resultsaix-hub/v1/share. If you cannot change the firewall, use the send code below.

Sending instead of reading:

1. On your main site, open the Hub, then Settings, then Linked sites. Copy the send code shown under Cannot this Hub reach a site? It starts with RAIXSEND.
2. On the other site, open the Hub, then Settings, then Linked sites. Paste it into the box under Cannot your main site reach this one? and press Send my numbers there.
3. That is the whole setup. The other site introduces itself to your main site and sends its numbers straight away. If it was not shared yet, it is shared automatically, and the message says the main site has this site's numbers.

After that, the other site sends its numbers every ten minutes. Your main Hub uses sent numbers as they are while they are less than 45 minutes old, and does not try to read the site in that time.

A real example:

Jamie links shop.yoursite.com, which sits behind a CDN firewall. On yoursite.com the Overview block for it says the security service in front of that site blocked the request (error 403). Rather than change the firewall, Jamie copies the RAIXSEND code from yoursite.com, pastes it on shop.yoursite.com and presses Send my numbers there. A minute later the shop's sections appear on the main Overview, and the shop's Linked sites card says Sending to yoursite.com every ten minutes.

Checking and stopping:

• The sending site shows where it sends to and when it last sent, or the reason nothing has arrived yet
• Send now sends straight away, handy after a fix
• Stop sending stops it, after a second click to confirm. Your main Hub stops showing that site once its last numbers go stale

Nothing else changes:

Sent numbers are exactly the numbers the main Hub would have read: counts, chart numbers and names, with no email addresses and no licence keys. Every send is signed with the site's secret and refused if it is more than five minutes old. The sending job appears on that site's Diagnostics tab as Linked-site send, every ten minutes.

Tips:

• Sending is the easiest fix whenever a firewall is involved. You do not need to touch the firewall at all.
• Make sure WordPress's scheduled tasks run on the sending site: the ten minute send is one of them.
• More about linking in Linked Sites: Show Another Site On Your Main Hub.