1) 'Host A will receive the local certificate from Host B and will use the CA-Certificate to validate it' --- In simple terms you are right.
2) At no point of time Host sends the CA certificate to other host generally. It only sends the local certificate. The receiver checks whether he has a trust chain built.
e.g. Only if ''CA-Sales - CA-Root'' trust chain is built on Host A and ''CA-Marketing - CA Root'' chain is built on Host B (This generally happens when you load host and CA certificates on device) they will be able to authenticate each other based on their local certificates.
When i was studying it was said that you may receive a certificate chain from a remote peer containing EE certificate and intermediate CA-certificates and you will use the common CA certificate to validate the top CA-certificate and then you will use this intermediate CA certificate to validate the next and so on til validate the end entity certificate 😞
Welcome to the real world. To be honest, sometimes "the other vendor" has a very clear and easy explanation of standard features. Which after getting a clear understanding, you just need to see how said feature is implemented on Junos.
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