If the third party devices support features required by Multi-Pod IPN (modified MTU, PIM Bidir, DHCP Relay, sub-interfaces, OSPF, etc.), is it possible to use them for IPN?
Yes of course, go through the following and make sure the IPN meets the described requierements:
Hope that helps.
Thank you for your input.
Is there any official document on other third party vendors regarding this? Since apparently on Cisco docs while it stated any arbitrary IPN could work, didn't specify if there are supports or configuration for third-party IPN devices.
(Unlike PBR, where Cisco officially stated that it would work with other vendors like Palo Alto, CheckPoint, etc. And vice versa. There are none like this for Multi-Pod/Multi-Site IPN/ISN)
There is no official list of 'supported' vendors, and personally, I do not see the need of such a list. I see it like this: any model of router from any vendor will work, as long as it supports the IPN requirements.
In case of PBR, I think they made a list of supported firewalls, as there might be a lot of requirements for different firewalls to be integrated in a SG (it's just a guess).
In case of IPN, being just a IP network, the expectations are to just forward traffic.