RB2011 NAT + SFP / Switch1

We had something weird happen on two RB2011s.

Setup:

  • WAN Uplink - Fiber - SFP1 / Switch1
  • Customer Handoff - Copper - Ether1 / Switch1

If we enable NAT of any kind on the customer handoff the 2011 goes incredibly sluggish or reboots. If we move the customer handoff to ether6 / Switch2 the problem goes away. This is fully repeatable on two different 2011-RMs.

Has anyone else seen this type of behavior or is this a known thing?