SFP+ Ports on the C1300-24XT compatibilty and other questions.

[SpacemanSpiff]

Hello all,

Background:
I'm building a home lab and have just finished running wires through the walls to a patch panel. I was going to get a C1300-24XT and I'm going to have a Netgate 8200 as my WAN access and router. The Netgate only has 2.5G LAN ethernet connections. I was going to get a multigig SFP+ that's compatible with Cisco devices over copper and install it in one of the 4 SFP+ ports on the C1300.

Questions:

1. Will the setup work? Meaning can the Switch use the SFP+ ports in this way or are those ports limited to something like only stacking?
2. Right now I'm going to be maxed out on ports exactly on the 24XT. In the future if I want to expand and get a second switch, can I have some of those SFP+ ports configured as described but then use a different one (or two) as stacking ports? Or do all of the SFP+'s need to be in the same mode?

Thank you for your help!

[Enes Simnica · Accepted solution]

hello G. The C1300-24XT paired with a Netgate 8200 is a solid combo, and running in-wall cabling to a patch panel sets you up for a clean and scalable environment.

To your first question yesssir, your setup will work as described. The SFP+ ports on the C1300-24XT are general-purpose uplink ports and are not restricted to stacking only. You can absolutely use one of them to connect to your Netgate firewall using a multigig SFP+ module. Just make sure the module supports 2.5G over copper (like Cisco's SFP-10G-T or a compatible third-party model), and the port will auto-negotiate down to match the 2.5G link speed from your Netgate.

As for expanding in the future, you can definitely use some SFP+ ports for WAN or LAN uplinks and others for switch-to-switch connectivity. The C1300 series does not require all SFP+ ports to operate in a single mode. So if later on you want to link a second switch, you can use one or two of the remaining SFP+ ports for that purpose without impacting the one you're using for your firewall. Stacking, in the traditional Cisco sense (like StackWise), is not mandatory or enforced across all SFP+ ports on these switches. In most lab or SMB setups, you'd just connect multiple switches using standard trunk links or EtherChannels across those uplinks. and for sure, let me know if you'd like module recommendations or help with the port configs once you're ready to expand.

Hope it helps G.

-Enes

[SpacemanSpiff]

Perfect, thank you for the confirmation.

I was looking at this SFP+

I appreciate the offer. I'll definitely be back when I get the device in and starting to configure it.

Thanks!

[Jens Albrecht · Accepted solution]

Hello @SpacemanSpiff,

yes, that's going to work.

By default all ports are regular switchports and it is up to you to configure some ports as stackports as required.
You can also choose to use either some copper ports or SFP+ ports as stackports as follows:

interface <type><num>
  stack port enable

So you can easily verify this yourself by reserving 1 or 2 ports for stacking by putting the above config.

HTH!

[SpacemanSpiff]

Awesome, thank you!

[Jens Albrecht]

You're welcome!

Just noticed that you mentioned above that you plan to use the SFP-10GM-T-30 modules.

Did you check the official list of supported SFP modules on the Cisco Catalyst 1300 Series Switches Data Sheet?

The module you mentioned is not listed there so you might want to check the list and reconsider going for a different module.

[SpacemanSpiff]

Yeah so that kinda gets to something else I wasn't sure of. Looking at the list of compatible SFP+'s there aren't any 2.5G copper listed. I was seeing a few different forum posts on reddit and lemmy that Cisco can be very specific in speeds so people were advising caution against using a 10G SFP+ on one side that didn't explicitly state that it can negotiate down to 2.5G. That's when I found the one I linked above from FS. Their documentation states that it's compatible with Cisco and that it will negotiate automatically. They state you just have to operate the SFP+ port on the switch at full 10G, then the plug will handle the rest.

Please let me know if that's incorrect and if a SFP-10G-T-X would still work with a 2.5G connection on the other side.

[Jens Albrecht]

I have no experience with this module so that I cannot answer this question.

You can ask the vendor whether it works with the C1300-24XT and whether you get a refund if it fails.
Some Cisco switches accept a large variety of modules while others are extremely picky so that 'compatible with Cisco' is a pretty elastic term.

[SpacemanSpiff]

That's fair. Ok, thanks! I'll ask the vendor then.

[KJK99]

The C1300-24XT is not a multi-gigabit switch so I don't think it will work at 2.5G no matter what module you plug into it. Get a C1300-24MGP-4X instead, if you want 2.5G links. There are no C1300 switches with 10G multi-gigabit ports. Also, plan to connect copper ports to copper ports for the best performance and to avoid any compatibility issues.

[SpacemanSpiff]

Yeah I think you're right. Unfortunately the MGP doesn't provide enough 10G ports. I attached a diagram of what I'm trying to design.

The Netgate LAN ports on the right only operate on 2.5G. I have 20 x 10G capable cables that I ran through my wall so I'd like my switch to be able to match the 10G speed. 

Something I'm confused about though is Cisco says the 24xt has 20 x 10G copper ports and four 10G copper/SFP+ ports. But the pictures clearly show 24 RJ45 ports and 4 SFP+ ports. So are the pictures wrong or are the specs wrong?

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-1300-series-switches/nb-06-cat1300-ser-data-sheet-cte-en.html#Productspecifications

EDIT: Also, the suggestion I was given by the SFP+ vendor is to put the 10G SFP+ through a media converter and they provided the second picture I added.

[Jens Albrecht]

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@SpacemanSpiff wrote:

Something I'm confused about though is Cisco says the 24xt has 20 x 10G copper ports and four 10G copper/SFP+ ports. But the pictures clearly show 24 RJ45 ports and 4 SFP+ ports. So are the pictures wrong or are the specs wrong?

There is nothing really wrong with the specs but the wording is probably somewhat misleading.
Looking at the Catalyst enterprise-class switches, the SFP ports are always additional ports so that you would have 28 useable ports in total (24 copper plus 4 SFP ports).

However, in case of the SMB switches Cisco is doing what other vendors already do for many years.

So the 'four 10G copper/SFP+ ports' mean that they are not independent but set up inline. If you look at the picture of the switch you will notice that the last 4 copper ports are numbered 21 - 24 and the same numbering is shown for the SFP ports. This means that e.g. copper port 21 will go offline as soon as you insert a SFP into the SFP slot 21 and this link goes up. Once the SFP link goes down, the copper link will come back online.

As a result you can only use a total of 24 ports at the same time and the other 4 ports can only be used for backup purposes.

Just a quick note on media converters:
I know some customers that use media converters a lot because the have to. However, they can make troubleshooting more complex so I only consider them as a last resort.

[SpacemanSpiff]

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@Jens Albrecht wrote:

So the 'four 10G copper/SFP+ ports' mean that they are not independent but set up inline. If you look at the picture of the switch you will notice that the last 4 copper ports are numbered 21 - 24 and the same numbering is shown for the SFP ports. This means that e.g. copper port 21 will go offline as soon as you insert a SFP into the SFP slot 21 and this link goes up. Once the SFP link goes down, the copper link will come back online.

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Ahhhh ok that makes more sense. Yeah I had no idea that's what they would mean.

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@Jens Albrecht wrote:

Just a quick note on media converters:
I know some customers that use media converters a lot because the have to. However, they can make troubleshooting more complex so I only consider them as a last resort.

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Yeah that's kinda my gut feeling with a media converter like that. Adding those extra hops isn't something I'd want to do if I can avoid it.

To that end, I also found out two things from Netgate's documentation that's throwing another wrench into things. First is that, apparently, Netgate's 10G WAN ports aren't really compatible with copper apparently so now I'm not sure how I'm going to connect the ISP into Netgate...

The second thing is that the Netgate's ports are apparently reconfigurable, they're just configured from the factory in the way they're labelled but don't need to actually stay that way. To me that means I could technically take WAN4 and make it LAN instead. That would mean then I'd have a 10G LAN connection that I could connect to the 10G SFP+ from the switch and that would alleviate that issue. Then I would just need to figure out how I'd get the ISP to work with the Netgate.

But back to your answer. If I do have 24 physical connections...and I'm not going to use all of the SFP+ ports...could I plug one of the 24 RJ45 ports on the switch into one of the four LAN ports on the Netgate? Even though the switch is 10G ethernet...would that negotiate down to the 2.5G speed of the Netgate?

[Jens Albrecht]

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@SpacemanSpiff wrote:

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But back to your answer. If I do have 24 physical connections...and I'm not going to use all of the SFP+ ports...could I plug one of the 24 RJ45 ports on the switch into one of the four LAN ports on the Netgate? Even though the switch is 10G ethernet...would that negotiate down to the 2.5G speed of the Netgate?

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Sorry, but the answer is a no!

The XT models offer only standard 1G or 10G ports like the majority of other Catalyst 1300 models and do not support mGig.

Only the "MGP" models (which stands for multigigabit ports) provide mGig support at 100 Mbps, 1 Gbps, and 2.5 Gbps speeds per port. So the C1300-24MGP-4X or C1300-48MGP-4X offer 8 or 16 mGig ports but the downside is that the other copper ports are limited to 1 Gbps only. Probably not what you want/need.

[SpacemanSpiff]

Well crap...I thought maybe the ethernet would negotiate at least and the multigig ports you're talking about were just for SFP+'s...

So...maybe I'm just entirely off base with this...if the case is that the switch will only operate on 1 or 10G...what happens when the other end of the patch panel is attached to my PS5 or Switch or any other network device...It sounds like then if those devices can operate on 1G or 10G then the switch would be fine because it could do those speeds but in the strange case of the Netgate that does 2.5G, that's where things get squirrelly. 

I feel like I'm making this more complicated that it needs to be...really it seems like the netgate is the only thing I need to solve. As long as I get a way for the Netgate to talk to the switch at 1G or 10G but nothing else, then that solves that problem. I guess I'll assume that every other "normal" device (ie. PS5, Switch, PC's, Synology, etc.) on the network will likely talk on 1G so that would be fine with the switch. Then I'll need to figure out how to make the ISP talk to the Netgate.