Rack rails on network equipment

Mon Sep 27 10:07:30 UTC 2021

* Andrey Khomyakov

> Interesting tidbit is that we actually used to manufacture custom rails for our Juniper EX4500 switches so the switch can be actually inserted from the back of the rack (you know, where most of your server ports are...) and not be blocked by the zero-U PDUs and all the cabling in the rack. Stock rails didn't work at all for us unless we used wider racks, which then, in turn, reduced floor capacity.
> 
> As far as I know, Dell is the only switch vendor doing toolless rails so it's a bit of a hardware lock-in from that point of view. 

Amen.

I suspect that Dell is pretty much alone in realising that rack mount
kits that require insertion/removal from the hot aisle is pure idiocy,
since the rear of the rack tends to be crowded with cables, PDUs, and
so forth.

This might be due to Dell starting out as a server manufacturer. *All*
rack-mount servers on the market are inserted into (and removed from)
the cold aisle of the rack, after all. The reasons that make this the
only sensible thing for servers apply even more so for data centre
switches.

I got so frustrated with this after having to remove a couple of
decommissioned switches that I wrote a post about it a few years back:

https://www.redpill-linpro.com/techblog/2019/08/06/rack-switch-removal.html

Nowadays I employ various strategies to facilitate cold aisle
installation/removal, such as: reversing the rails if possible,
attaching only a single rack ear (for four-post mounted equipment) or
installing rivet nuts directly in the rack ears (for shallow two-post
mounted equipment).

(Another lesson the data centre switch manufacturers could learn from
the server manufacturers is to always include a BMC. I would *much
rather* spend my serial console infrastructure budget on switches with
built-in BMCs. That way I would get remote power control, IPMI Serial-
Over-LAN and so on – all through a *single* Ethernet management cable.)

Tore