3

Is this possible? Our setup:

  • Core switching: Catalyst 2960-X
    • 48 x 1GbE RJ-45 ports
    • 2 x 10GbE SFP+
    • Uplinks between switches are RJ-45. We plan to get rid of these and use a 10G switch for switch-to-switch uplinks in the near future.
  • Appliance: QuantaPlex T41S-2U Blade Server
    • 8 x 10GbE SFP+ ports (each blade has two)

We want to utilize the 10GbE SFP+ ports on the Catalysts for the time being as we have not received our 10GbE switch and would like to do some testing with the appliance while we wait for the switch to arrive.

Right now, the blades see that they are connected to a switch, but are not able to get an IP manually or via DHCP in Windows and Linux. I initially thought this may have been an issue with the SFP+ DACs, but it appears to not be the case. We have tried doing this with and without LACP, with no progress in either case.

DACs are Cisco SFP-H10GB-CU5M.

Brendan Lovett
  • 31
  • 1
  • Aren't the two SFP+ slots on the switches uplink ports? – Lenniey May 28 '19 at 14:36
  • No, not at the moment. As mentioned above, uplinks are currently just RJ-45. That's why we thought we could use them temporarily. – Brendan Lovett May 28 '19 at 14:37
  • I mean per definition, as in: you can _only_ use these ports for uplink. – Lenniey May 28 '19 at 14:39
  • 2
    I don't believe so? Granted, this is not my area of expertise. I'm learning this as we go, as we have no network engineers on our team right now. We had a CDW consultant do the configuration and he didn't skip a beat when we asked him to do this, and couldn't figure out why it didn't work either. – Brendan Lovett May 28 '19 at 14:44
  • https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-2960-x-series-switches/datasheet_c78-728232.html says: _4 fixed 1 Gigabit Ethernet Small Form-Factor Pluggable (SFP) uplinks or 2 fixed 10 Gigabit Ethernet SFP+ uplinks_. I have not worked with these switches before, but this could be the problem. Some are uplink only, some not (someone else here should know). – Lenniey May 28 '19 at 14:47
  • From what I've read, this means that they are not expandable. You buy the switch with SFP or SFP+, and you do not have the ability to swap them out for one another (e.g. you wanted to move from SFP to SFP+). The configuration for the physical interfaces are fixed, but not necessarily the function of the physical interfaces. Again, take that with a grain of salt. Appreciate your help either way – Brendan Lovett May 28 '19 at 14:55

1 Answers1

2

The "uplink" ports on a Cisco 2960-X switch will work exactly like any other port (albeit with more speed options), and the behaviour will depend on the config applied to the port.

If the link layer is up thanks to the DAC, then the ports will work fine assuming that the config is appropriate at each end. I would try setting them as static access ports and be very certain that the ports are in the same VLAN as your DHCP server.

You could post here the config lines from an example 1G port and the 10G ports.

Daniel K
  • 633
  • 1
  • 4
  • 15