Solved Telnyx IP Whitelisting Request f/ DDoS Mitigation

[[email protected]]

Good Morning:

As part of their ongoing DDoS mitigation strategy, Telnyx is requesting that we whitelist our endpoint IP addresses in their account control panel. For my main 3CX installation, it is on-prem and adding my static IP to the whitelist seems straight forward enough. However, what about a Hosted by 3CX instance using the SBC. Assuming that the Hosted IP address can change periodically, it would not be practical to update the whitelist with that sort of frequency or if you had many deployments you were managing simultaneously.

Really, I'm more just looking for some official guidance since Telnyx is a preferred trunk/sms provider.

Thanks in advance for the help!

 

[cobaltit]

Long answer:

So if you go into the dashboard for your hosted 3CX instance and look at the IP address it should say static. By definition, that doesn't mean it can't change, rather that it shouldn't change often. That being said, one of the requirements of being a 3CX supported provider for hosted 3CX is registration-based SIP trunks so if the IP does change (which should only happen if there is a serious outage at DO) then your voice will follow.

The fact that Telnyx is a preferred provider has nothing to do with your request as any provider with this requirement would have the same question. Ultimately, the burden should be on Telnyx to support adding FQDNs which would solve the issue, but they have bigger problems right now.

Telnyx is only saying to whitelist if you are having audio issues. If you aren't you can probably ignore.


Short answer:

Just add the IP and be done with it. DO would have to have an issue/outage for an entire datacenter/region for your 3CX IP to change.

 

[YiannisH_3CX]

Just add the IP and be done with it. DO would have to have an issue/outage for an entire datacenter/region for your 3CX IP to change.

Exactly that. If you can add your IP then do so. If you cannot then it is not necessary unless you are experiencing audio issues. If you are using Hosted by 3CX you can temporarily add your public IP in Telnyx until things have settled down and remove it once the issue has been resolved.

 

[[email protected]]

Telnyx is anticipating additional attacks today 11-15-21, and is advising that all customers add their IP addresses to their account Whitelist.

Just an FYI.

Thank you both for your replies. I think this thread can be closed as resolved.

 

[YiannisH_3CX]

Thank you for the update. Marking this one as resolved but you can always create a new thread if you face any issues down the line