Switching

We will be swapping out some EX-4200-48P switches due to EOS with EX-3400-48P switches. I see that the part numbers for the optics we need have not changed, e.g EX-SFP-10GE-SR. Is there any benefit to replacing these optics if they are still working fine?  Are there any noteable advancements in newer hardware revisions? 

Hi,

First offtopic -

depending on intended use EX3400 may or may not be most suitable replacement for EX4200. EX4300 is direct replacement for EX4200.

If needed check here:

https://apps.juniper.net/feature-explorer/compare-multiple.html#pkey=30504200%7C30504300%7C30503400&platforms=EX4200%7CEX4300%7CEX3400&stat=0.01181865831171991

Regarding SFP+ - 

if cost is no issue, buy new SFPs as you get warranty with them. But nothing is also wrong with continuing use of existing ones. I don't know about possible advancements in new HW revisions though ...

Sorry stupid me, probably was too tired yesterday, EX4200-48PX is direct replacement of EX4200-48P, so you can also get those instead ...

Replacing an EX4200-48P with an EX3400-48P is fine.  There is no need to 'must' go with EX4200-48PX.  Please note the EX3400 using newer "ELS Cli" vs older EX4200 so some conversion of your config will be required.  There is an ELS conversion tool to assist you with this.

As for optics, you are talking about for UpLink module, which on EX3400 is built-in ports.  Yes those optics should be fine to move to new switch, and if they were Juniper purchased Optics, and your EX4200-48P (and your new EX3400-48P) are both under Support, the Optics should still be covered as well.  Support (outside of Core or Core Plus, I believe) covers the switch and everything related to it, including Optics.

Also note that if this switch is to be part of a VC, the whole VC will need to be EX3400 based, and that VC connectivity is generally provided by the 40GE interfaces, via 40GE DAC cables, vs older VC cables with EX4200 family.

Thanks for the input, my intention wasn't for this to become a comparison of the two models, but even so, we're already using the 3400 and it has been great; love the form factor and performance. I don't see why anyone would buy the 4200-PX when the 3400 has just about twice the backplane and overall throughput and comes with four 10-gig uplinks and QSFP and typically costs less. I think the only thing we've missed so far is the LCD screen which can sometimes come in handy and also the 'T' models have 8 PoE ports which is nice when you just have a few  PoE devices. 

I didn't realize there was a formal terminalogy for the configuration differences (ELS), but definitely found that out the hard way. I'll check out the conversion tool for this next upgrade as the configuration is a bit more complex than our previous replacements.

Per your comments about the warranty on optics, we should be covered so we'll just stick with the ones we have. However I assume the RMA process would be similiar to other removable components such as power supplies and one time when we had a power supply fail, it was purchased on a separate order from the switch itself, so they gave me a hard time when trying to RMA it and they ended up replacing the entire switch instead of just the failed PS because it was easier than trying to find the necessary documentation to prove it was associated with the switch. All this to say I wouldn't be surprised if I have to jump through a few hoops to get them replaced in the unlikely event they fail, given that they've moved from switch to switch. 

I think we are on the same page.  Just FYI but Juniper HW support is determined by SN.  I assume you purchased the 2nd power supply as redundant after the fact.  For that to get service, someone (Partner?) needs to tie the PS to the EX chassis.  That is not the case for Optics, so you should be all set there.

Yes for much of EX Access switches, PS and Fans are NOT FRUs - Field Replaceable Units.  So for such failures you'll get a replacement switch, for which you take out the parts you need and then put them into the switch you received and then send back whole switch.  Yes, may not make much sense, but way it is.

If you had an Optics failure, they will not send you a whole switch -:)