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85586
PowerConnect 2824 SFP Ports Not Working
We bought a new PowerConnect 2824 with a corresponding SFP module to replace an older 2724 and SFP module.
After configuring the switch and installing it, we were unable to get a connection on our fiber uplink.
The SFP light lights up and blinks occasionally, and the switch properly detects that SFP module is inserted and the fiber is plugged in. We can see the SFP insertion being detected and the switch changing to fiber mode by watching the console output, and the web administration port status page lists the port as "ComboF" when the SFP module is inserted and the fiber is connected.
However, the switch always reports that the port status is down. (The port is not administratively disabled.)
The old switch works fine with the old SFP module. The new switch does not work with either the old or the new SFP module. We've tried both SFP combo ports. We have also verified that the fiber itself is fine. We cannot get the new switch to show the combo port status as up when using the SFP module. We've tried completely resetting the new switch by deleting the config file via the boot menu over the serial connection and running the initial setup wizard again, but the port will still not come up.
Any ideas?
AAIT
6 Posts
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January 27th, 2015 11:00
After some testing yesterday, we determined that the auto negotiation setting had to be disabled for the switch to work with our fiber-copper media converters.
The 2724 works fine with our media converters with auto negotiation enabled.
The 2824 works fine with auto negotiation enabled when connected to another SFP transceiver in the building switch.
But when we introduce the media converter into the path, the 2824 will only bring the link up if you disable auto negotiation.
Everything looks good so far.
AAIT
6 Posts
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January 9th, 2015 10:00
We have the Dell 1000BASE-SX 850nm SFP module. The part number is GF76J and the description is "Dell Networking, Transceiver, SFP, 1000BASE-SX, 850nm Wavelength, 550m Reach". It plugs into the new PowerConnect 2824 switch.
The fiber run is relatively short (less than 220 meters), and is 62.5 um, multimode terminating at an ST connection in our network closet. We have ST-LC patch cable going to the SFP module.
The old switch is a PowerConnect 2724, part number TJ689. The old SFP module is what was offered with the switch at the time of purchase - I don't have a part number on hand, only the description from the order sheet: *Dell PowerConnect 2724 with SFP Transceiver, 1000BASE-SX (LC Connector)". I can also confirm that it's 850nm.
The old switch and old SFP work fine. Moving the fiber from the old SFP in the old switch to the new SFP in the new switch results in no connection. The new switch changes the port mode to fiber, but the link stays down. Using the old SFP in the new switch results in the same situation.
AAIT
6 Posts
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January 9th, 2015 13:00
I'm connected via telnet, at console# (the EXEC command mode).
show logging and show logging file are both unrecognized commands. I can show ip or show tech-support. None of the other commands (show clock, show system, show version, etc.) listed in the manual work either. I am logged in as admin (level 15). Again, this is after a fresh configuration reset performed according to the "Erasing the Device Configuration" instructions on page 51 of the manual. After this, the wizard was entered and we supplied only the basic IP information. Then we set up VLANs and membership/PVID for the appropriate ports.
When inserting the SFP module I can see it in the console output. I can also see when the fiber is connected and the combo port switches from copper to fiber. I can also see similar activity when disconnecting the fiber or when removing the SFP module.
We haven't tried creating a loop between the two SFP ports, but since neither port actually comes "up" I don't think it would do anything. The optical transceiver test lists not applicable or not present for all the data (temperature, etc.). On the old switch, the data is populated.
AAIT
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January 9th, 2015 15:00
I looked up the part number of the new SFP module: 0GF76J It also has FTLF8519P3BNL-FC on it.
The new switch's uplink port is a tagged member of VLAN A, B, and C.
The PVID of the uplink port is A.
The old switch's uplink port is a tagged member of VLAN A, B, and C.
The PVID of the uplink port is A.
The old switch works with this configuration.
There should be no need to have the port be an untagged member of the VLAN its PVID is set to. This is not needed for the old switch, and according to the manual, the PVID simply sets a VLAN ID on untagged incoming packets. This all works when we connect the uplink port via copper.
From the manual:
"The VLAN Port Settings page contains fields for managing ports that are part of a VLAN. The port
default VLAN ID (PVID) is configured on the VLAN Port Settings page. All untagged packets arriving to
the device are tagged by the ports PVID."
From the built-in help:
"PVID (1-4095) — Assigns a VLA N ID to untagged packets. The possible values are 1-4094. VLAN 4095 is defined as per standard and industry practice as the discard VLAN. Packets classified to the Discard VLAN are dropped."
As I stated before, the optical transceiver test shows "Not Applicable" and "Not Relevant" for all values.
The only configuration difference I can see is that on the old switch, Ingress Filtering is disabled on the uplink port. On the new switch, it is enabled, though it shouldn't matter as that port is a member of all VLANs we need traffic on.
I cannot disable it on the new switch - I get an error: "Port g23 must be set to Dot1x Multiple Host, Ingress filtering cannot be disabled.." On the new switch, port based authentication is globally disabled.
For Port Based Authentication, we have the following (all default):
Global Parameters
Port Based Authentication State Disable
Authentication Method Radius
Guest VLAN
VLAN List None
Interface Parameters
Interface g23
User Name
Admin Interface Control Authorized
Current Interface Control Authorized
Authentication Type 802.1x Only
Dynamic VLAN Assignment Disable
Guest VLAN Disable
Periodic Reauthentication Disable
Reauthentication Period (300-4294967295) 3600
Reauthenticate Now
Authentication Server Timeout (1-65535) 30
Resending EAP Identity Request (30-65535) 30
Quiet Period (0-65535) 60
Supplicant Timeout (1-65535) 30
Max EAP Requests (1-10) 2
For Multiple Hosts, we have the following (all default):
Port g23
Host Authentication Single
Action on Single Host Violation Discard
Traps Disable
Trap Frequency (1-1000000) 10
Status Not in auto mode
Number of Violations 0
Again, this all works when we connect the uplink port via copper, so I don't think any of the authentication / multiple hosts stuff is the problem. We're using port 23 on the new switch connected to the old switch via copper, with all VLANs tagged. The old switch has its port 23 connected to the fiber via one of its SFP modules. The old switch and its SFP module are acting as a media converter at this point, and everything works.
Of course, we need it to work on the new switch alone. When we use port 23 on the new switch connected to the fiber directly via the SFP module, port 23 switches to fiber mode and stays down. The same happens when we try port 24. The same happens when we try the old SFP module (which works in the old switch) in either SFP port on the new switch..
AAIT
6 Posts
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January 12th, 2015 09:00
The switch connects to a fiber to ethernet media converter. The media converter connects to a building switch via ethernet. This isn't the exact model of media converter, but it's very similar to what we have.
www.provantage.com/transition-networks-cgetf1013-110~7TRN90K9.htm
The media converter we have has 5 diagnostic lights - power, fiber link, fiber receive, ethernet link, and ethernet receive. When using the new switch, everything but fiber receive lights up. When using the old switch, everything lights up and everything works.
We've already tried replacing the media converter, and we've also tried forcing the building switch port to 1000 Mbps vs. leaving it on auto negotiate.
The building switch does have STP enabled. STP packets / learned MACs are some of the things the network staff look for to determine if a link is up or down. They see no STP traffic / learned MACs when we use the new switch.
Everything on the 2824 should be default, except for the following:
The switch is in managed mode.
The switch has an IP address, subnet, and default gateway configured.
There are 3 VLANs defined.
Ports are configured as members of these VLANs, as appropriate.
Ports have their PVID set to our default VLAN (one port is left with the default PVID of 1 so we can get to the web management).
Here are all the STP settings.
Spanning Tree Global Settings
Spanning Tree State Enable
STP Operation Mode Rapid STP
BPDU Handling Flooding
Path Cost Default Values Short
Bridge Settings
Priority (0-61440 in steps of 4096) 32768
Hello Time (1-10) (Sec) 2 (SELECTED)
Max Age (6-40) (Sec) 20 (NOT SELECTED)
Forward Delay (4-30) (Sec) 15 (NOT SELECTED)
Designated Root
Bridge ID 32768-ma:ca:dd:re:ss:00
Root Bridge ID 32768-ma:ca:dd:re:ss:00
Root Port 0
Root Path Cost 0
Topology Changes Counts 62
Last Topology Change 0D/ 0H/ 36M/ 27S
STP Port Settings
Select a Port g23 (our uplink)
STP Enable
Fast Link NOT checked
Root Guard NOT checked
Port State Forwarding
Role Designated
Speed 1000M
Path Cost (1-200000000) 4
Default Path Cost NOT checked
Priority 128
Designated Bridge ID 32768-ma:ca:dd:re:ss:00
Designated Port ID 128-23
Designated Cost 0
Forward Transitions 1
LAG
Rapid Spanning Tree (RSTP)
Interface Port g23
Role Designated
Mode RSTP
Fast Link Operational Status Disable
Point-to-Point Admin Status Auto
Point-to-Point Operational Status Enable
Activate Protocol Migration Test
We don't have any LAGs in use - all 24 ports are blank on the LAG Membership page.
From what I can tell, the SFP ports on the new switch just don't work.