IP Distance Gateway (host port blocking)

[Amar_Joshi]

I am reading the best practices for EVA and mpx110b (IP distance gateway) best practice pdf and part of best practices it mentions -

"Use a 2-fabric (dual fabric) configuration only if the host traffic cannot be separated from the replication traffic. This is recommended only when the customer business requirements permit it. Care should be taken when designing a two-fabric configuration over FCIP links as host port blocking can occur."

Can someone explain what does it mean by term "host port blocking" and why is it of a concern when EVA/switch ports are meant to be sharing 2-way traffics?

Thanks in advance.

[Del_3 · Accepted solution]

Run this presentation segment from Tech Forum in 2009 in slide show. The animation slides are what HP is talking about with host port blocking.

[Amar_Joshi]

Thanks Del,
Does anyone ever asked the question that with EVA8400 (8 ports@4Gb) we should still be bothering for such occurances?

[Del_3]

I hope I understand your question. The problem has nothing to do with speed of the EVA but its often the slow speed of the FC-IP link that "chokes" the EVA and then eventually throttles host I/O to the array. That is what the ppt was trying to show.