Avoid overlapping rekeys of backup and main tunnel

[ricardomacas]

Summary

This change will encourage users to not depend on their control plane at exactly the same moment for their pair of tunnels.
Guidance is proposed to offset the backup tunnel for an hour prior to ensure that should the main tunnel be rendered nonfunctional due to a control plane temporary error, the backup tunnel should have completed this transaction on a different moment where the issue likely did not manifest.

Documentation checklist

• The documentation style guide has been adhered to.

[ricardomacas]

Am reviewing today as per request.

[hyperlint-ai]

Howdy and thanks for contributing to our repo. The Cloudflare team reviews new, external PRs within two (2) weeks. If it's been two weeks or longer without any movement, please tag the PR Assignees in a comment.

We review internal PRs within 1 week. If it's something urgent or has been sitting without a comment, start a thread in the Developer Docs space internally.

---

PR Change Summary

Updated configuration guidance for VPN tunnels to prevent overlapping rekeys between backup and main tunnels, enhancing reliability during control plane disruptions.

• Encouraged users to offset backup tunnel configurations by one hour from the main tunnel.
• Updated configuration examples for AWS, Cisco, Fortinet, and VyOS to reflect new lifetime settings for IPsec tunnels.
• Provided guidance to ensure that backup tunnels do not rekey simultaneously with main tunnels.

Modified Files

• src/content/docs/magic-wan/configuration/manually/third-party/aws.mdx
• src/content/docs/magic-wan/configuration/manually/third-party/cisco-ios-xe.mdx
• src/content/docs/magic-wan/configuration/manually/third-party/fortinet.mdx
• src/content/docs/magic-wan/configuration/manually/third-party/vyos.mdx

---

How can I customize these reviews?

Check out the Hyperlint AI Reviewer docs for more information on how to customize the review.

If you just want to ignore it on this PR, you can add the hyperlint-ignore label to the PR. Future changes won't trigger a Hyperlint review.

Note specifically for link checks, we only check the first 30 links in a file and we cache the results for several hours (for instance, if you just added a page, you might experience this). Our recommendation is to add hyperlint-ignore to the PR to ignore the link check for this PR.

[marciocloudflare]

Hi @ricardomacas. PCX is in the middle of a revamp on the way we work and we're going through a backlog cleanup. Right now I need to close this PR since it's rather old by now. When you're ready to pick this up again, please ping me and I'll help seeing this through. Thank you!