On Thu, Apr 27, 2023 at 2:38 PM, Adam Thompson <athompson@merlin.mb.ca> wrote:
Fascinating. I’ve never had an ASR-1001 come with two sets of ears, and I also note that the text of the instruction manual doesn’t reference the rear set at all. I’ve never seen rear ears on any Cisco gear of my own, nor on anything the local ILEC has installed either. I think the diagram is in error here.
However, the “optional” step 1 is a pretty solid hint (i.e. pretty much a clue-by-four upside the head, here!) that you really should use a shelf. As in you REALLY SHOULD USE A SHELF of some kind.
Hah! Your mention of clue-by-fours while we are talking about drooping routers reminds me of one of my more useful tools. I have a bunch of bits of 2x4 which I've cut to around 1.75", 3.5", 7". These are really really helpful when trying to mount a piece of equipment under something which is either not screwed in, or is drooping at the back. You can use these as spacers when replacing a bit of gear which is supporting other bits of gear, or, with a small shim/flat screwdriver as a way to jack up a devices which is drooping at the back (and so slide in another device). There are much more elegant solutions (like a machinist jack), but a few off-cuts of 2x4 are cheap, light, and non-marring. This thread feels somewhat like "old NANOG" - people discussing actual issues that they run into, and then sharing tips and tricks to help with those issues. I miss this… W
It doesn’t even have to be a full shelf – any rail kit that relies on an “L”-shaped profile instead of interlocking sliding bits should support an ASR-1001 just fine, e.g. Tripp-Lite’s 4POSTRAILKIT1U. RackSolutions’ Universal Fixed Server Rack Rails <https://www.rack-solutions.ca/rack-rails.html> shows an example of a slightly different design that some prefer – it all works about the same way.
The other thing I’ve done is used a shallow cantilever shelf to support the rear end of equipment that only comes with ears, if it’s deep enough – something like StarTech’s CABSHELFV1U; the trick is finding a shelf that simultaneously doesn’t have the structural fold at the rear in the way AND doesn’t interfere with the device immediately below. You’d think there’re only 2 geometries of product to worry about, but there are actually more b/c there’s no standard – so test-fit first, or examine photos really carefully. This is usually more of a hack than a permanent, supportable solution, but sometimes it can work very well and very cheaply.
Or, just make sure you’re installing the ASR immediately above something that does have proper 4-post mounting rails. This is probably the single most common way to safely & securely mount “eared” devices in a 4-post rack that I’ve seen – that Dell PowerEdge server in the rack suddenly starts doing double-duty as a shelf! (Or the UPS, or the KVM, or the ethernet switch, or…)
-Adam
*Adam Thompson*
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*From:* NANOG <nanog-bounces+athompson=merlin.mb.ca@nanog.org> *On Behalf Of *Chuck Church *Sent:* Thursday, April 27, 2023 10:36 AM *To:* 'Mark Stevens' <manager@monmouth.com>; nanog@nanog.org *Subject:* RE: Standard DC rack rail distance, front to back question
Hey all, sorry I did mean to say ASR1001 (an X model to be exact). The 4 post mounting they show in a hardware mounting doc uses front and back ears, which I’ve never done: https://www.cisco.com/c/en/us/td/docs/routers/asr1000/install/guide/ asr1routers/asr-1000-series-hig/asr-hig-1001.html#task_1205646 see figure 16 slightly down from there.
I do see some generic rails from TrippLite that probably would work, as well as shelves. I was hoping a standard depth that most vendors honored for 4 post existed, but it doesn’t seem likely. We’ll have a variety of PaloAlto, Cisco, Checkpoint, and others co-habiting.
Chuck
*From:* NANOG <nanog-bounces+chuckchurch=gmail.com@nanog.org> *On Behalf Of *Mark Stevens *Sent:* Thursday, April 27, 2023 11:17 AM *To:* nanog@nanog.org *Subject:* Re: Standard DC rack rail distance, front to back question
Lucky you with a 19" data rack. All I have are 23" telco racks but I will say, the 23" extension ears from Cisco are serious and my router chassis' don't sag.
Mark
On 4/27/2023 10:04 AM, Chris Marget wrote:
On Thu, Apr 27, 2023 at 9:53 AM Chuck Church <chuckchurch@gmail.com> wrote:
for a Cisco ASA1001, there aren’t rails, but rather front and back ‘ears’ you use to hit both front and back posts.
Front *and* back ears? I'm not sure what an ASA 1001 is (ASR?) but my experience with these boxes is that they have a single pair of ears which can be mounted front OR back.
The heavier / deeper 1RU devices do tend to sag alarmingly.
Is there a ‘standard’ distance between front and back rails that devices usually adhere to?
If you're thinking of setting the front/back distance to accommodate a specific device, table 2 might be of some interest:
https://i.dell.com/sites/doccontent/business/solutions/engineering-docs/ en/Documents/rail-rack-matrix.pdf