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logan92's avatar
logan92
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Jul 13, 2024

How to redirect outbound traffic to 2 ISP links

Hi, We have (LTM,GTM) , Can we implement LTM & GTM behind the firewall? and if yes ,how the LTM can monitor the 2 ISP links on the firewall? is it by using transparent monitoring?
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Paulius's avatar
Paulius
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This does seem like it should function the way you would like with the exception of the health monitor. Keep in mind that with that monitor you're only monitoring the interface on the firewall rather than the connection from the firewall to the ISP so if routing is not functioning between the firewall and the ISP or the ISP has any routing issues that will not be detected.

Michael_Saleem's avatar
Michael_Saleem
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Jul 15, 2024

Since it's a transparent monitor, wouldn't the health monitor be checking the reachability from the F5's self IP via each ISP router to Google's public DNS server (8.8.8.8) and hence, this would verify that traffic using each ISP was working?

  • Paulius's avatar
    Paulius
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    Jul 18, 2024

    I believe you're right but it's always possible that you can still have an issue on that ISP and that singular destination is accessible but other destinations are not. Thank you for the correction, I missed that piece in the health monitor pointing to the other destination.