# Off-board external Ethernet Switch

**URL:** <https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866>\
**Category:** General Discussion\
**Created:** [April 23, 2026, 3:48pm UTC](https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866 "2026-04-23T15:48:56Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![3dMB](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/3dmb/32/13905_2.png) [@3dMB](https://discuss.bluerobotics.com/u/3dMB)\
**Post date:** [April 23, 2026, 3:48pm UTC](https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866/1 "2026-04-23T15:48:56Z")

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I seem to be constantly in a position of needing more bulkhead ports on the electronics enclosure. I had an idea for a way around this, if I were to put a ethernet switch inside a small 2" enclosure, run separate power and data on Cobalt connectors (already using on the ROV), linking the external and internal ethernet switches, is it fair to assume that the network would still play nicely? It would likely be Sonars and USBL running to the off-board switch, so not very data intensive.

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**Author:** ![tony-white](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/tony-white/32/18385_2.png) [@tony-white](https://discuss.bluerobotics.com/u/tony-white)\
**Post date:** [April 23, 2026, 5:25pm UTC](https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866/2 "2026-04-23T17:25:18Z")

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Hi @3dMB -

That certainly would work! You may be interested in this [product](https://ceruleansonar.com/product/manifold-5l-subsea-network-hub/).

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**Author:** ![3dMB](https://sea1.discourse-cdn.com/flex019/user_avatar/discuss.bluerobotics.com/3dmb/32/13905_2.png) [@3dMB](https://discuss.bluerobotics.com/u/3dMB)\
**Post date:** [April 23, 2026, 6:12pm UTC](https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866/3 "2026-04-23T18:12:52Z")

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Thanks @tony-white Though that Cerulean hub looks very nice, bar the 2" enclosure, I have all of the components required for a simple home assembly

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**Author:** ![amarburg](https://avatars.discourse-cdn.com/v4/letter/a/76d3ee/32.png) [@amarburg](https://discuss.bluerobotics.com/u/amarburg)\
**Post date:** [April 27, 2026, 4:14pm UTC](https://discuss.bluerobotics.com/t/off-board-external-ethernet-switch/22866/4 "2026-04-27T16:14:08Z")

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I’ve done exactly this with a GigaBlox (and a small terminal strip for power distribution) without issue.

As I’m using Wetlink penetrators, it is convenient that the BotBlox picoblade connectors will fit through an M10 hole.