refactor: cloud blockage

content/cloud/faq/index.md

@@ -133,7 +133,7 @@ The key practices helping to avoid source IP address blockage are:
  * connect to cloud infrastructure via single public facing jump / bastion node (using [sshuttle](https://github.com/sshuttle/sshuttle#readme) or [ssh ProxyJump](https://www.jeffgeerling.com/blog/2022/using-ansible-playbook-ssh-bastion-jump-host) or eventually [ssh ProxyCommand](https://blog.ruanbekker.com/blog/2020/10/26/use-a-ssh-jump-host-with-ansible/))
  * use OpenStack API to watch whether VM is ACTIVE
  * relax public IP try-connect loop timing
- * configure SSH client to [reuse connection for instance with `-o ControlMaster=auto -o ControlPersist=60s`]()
+ * configure SSH client to [reuse connection for instance with `-o ControlMaster=auto -o ControlPersist=60s`](https://en.wikibooks.org/wiki/OpenSSH/Cookbook/Multiplexing)
 
 As an example, consider a group of virtual machines, where at least one has access to the internet using an IPv4 or IPv6 public address, and they are connected by an internal network (e.g. 10.0.0.0/24).