Direct connecting various networking connections

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WeekendWarrior

Active Member
Apr 2, 2015
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I am thinking about building a pfsense-based router and would like to use a couple different interface types. This may seem like too much work but it would be a great learning vehicle.

One question I have is which interface topologies support direct connection between two NICs without an intervening router? I understand that 10Gbase-t allows this but what about 1Gb ethernet, SFP+, QDR, etc?

Another question is: are any obvious technical issues looming if I get the direct connections to work other than needing a powerful enough processor and enough PCIe connections to support the communication? I don't know how many concurrent connections would need to be supported but let's assume more than 5 10gig connections at once.

I would also like to originate several simultaneous VPNs from this router - any advice on what would tend to help that (to avoid processor support being the bottleneck)?

Any thoughts would be appreciated --
Dave
 

WeekendWarrior

Active Member
Apr 2, 2015
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As a follow-up to the questions above (and after reviewing a lot of forum postings):

SFP+ allows direct connection with DAC
1Gb or 10Gb ethernet allows direct connection based on Auto-MDIX
IB - no crossover cable needed
FC - uses a crossover cable

Also AES-NI support may help with high-speed VPN connections.
 

RTM

Well-Known Member
Jan 26, 2014
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With regards to infiniband, it is my understanding that if you are not using a switch, you must run a subnet manager like opensm on one of the two nodes.
 

Chuckleb

Moderator
Mar 5, 2013
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Minnesota
Even if you are using a switch, you still need a subnet manager somewhere in the fabric. This can run onboard the switch itself it supports it, or run from a node on the fabric. The overhead of opensm is pretty low.