[j-nsp] M5/M10/M20 gear questions

[Steve Steiner]

On Tue, Dec 16, 2008 at 12:13 AM, Charles Sprickman <spork at bway.net> wrote:

> Hi all,
>
> I am trying to gather some more info on the downside of the older/used
> gear.  On paper, it looks like anything from an M5 up would be more than
> capable of meeting our needs for the next few years.


EOL gear may not be supported by TAC.  Just something to keep in mind.


>
> It looks like with the exception of the ejector handle, the PICs are
> basically the same between the M5/10/20/7i.  If that's true, that's great
> news.


Yes, but this is totally unsupported and there are some differences.  A
non-ejector PIC is held to the FPC by means of screws from the bottom of the
FPC tray.  Ejector PICs are held in place by the rails and a catch on the
FPC.  So, technically, they work, but you have to be very careful when
inserting/removing them and there is no way to keep them from moving
sideways or coming unseated.


>
> On the GigE PICs, what is the main difference between the older and newer
> versions?  I will likely cheap out and go with just 2 or 3 of them and for
> the less bandwidth-intensive stuff stick one of them in a GigE switch and do
> the "router on a stick" config with VLANs.  Any thoughts on this?


Stay away from the very old GE-SX PICs as there were some with bad
firmware.  As for the "different" GE PICs, I assume you mean the differences
between the GE-SFP and the GE IQ/IQ2 PICs.  The IQ/IQ2 PICs move queing (and
other features) to the PIC from the FPC.  If you plan to run vanilla dot1q
with very little, if any, CoS the older GE PICs should be fine.  You really
see the differences in running things like VPLS, CCC encaps, tag rewrites
and stacks, etc.  You should check out the PIC guide for those chassis to
give you a better understanding of what's supported on each PIC type.


> As for the hardware, the nifty thing about these routers is that all the
> hard work of pushing packets around is done on the ASICs.  That's good and
> bad I assume since newer gear has newer ASICs.  What are the main features
> that a current generation router has that an older one would not due to
> limitations in the older ASICs?


Not much for those lines.  The difference becomes obvious when looking at
the difference between the LMNR chips versus the ABC chips versus the
I-chips.


> Since the routing engine is basically a PC running a modded FreeBSD distro,
> what's the story with moving parts there?  I'm having a hard time tracking
> down which models have flash for the RE and which use a hard drive.  I
> assume if there's a drive, it would be a wise investment to grab a new
> drive...


With the exception of the M7i/M10i, all other M-series use both CF and HDD.
CF is the primary boot device and the router (under normal conditions) boots
and runs from flash.  The HDD stores snapshots and logs and can act as a
secondary boot device.  If the router you get has been logging excessively
or running from HDD, that will reduce the lifespan of the HDD.  The M7i/M10i
can be equipped with internal CF and the newer ones shipped with them.  The
older ones had CF as an option.


> Lastly, are there any very good books covering the hardware peculiarities
> and JunOS in general anyone would like to recommend?


An oldie, but goodie, is the "Juniper Networks Routers: The Complete
Reference".  You can also get a lot of info from the Juniper website on
hardware.  "JUNOS Cookbook" is ok for what it is, and of course there is a
lot of info out on the Internet.

I have worked for small ISP's before, so I can appreciate your cost
concerns, but to be honest I don't think I'd run a revenue producing network
with EOL gear.  If you do, be sure to plan ahead and keep some spares on
hand.  Hardware failures always happen at the worst times. ;-)


>
>
> I think that covers it for now.
>
> Thanks again for all your help...
>
> Charles
>
> ___
> Charles Sprickman
> NetEng/SysAdmin
> Bway.net - New York's Best Internet - www.bway.net
> spork at bway.net - 212.655.9344
>
> _______________________________________________
> juniper-nsp mailing list juniper-nsp at puck.nether.net
> https://puck.nether.net/mailman/listinfo/juniper-nsp
>