This weekend I tried to move a fiber connection from one Catalyst 3508 to our central Catalyst 6513 equipped with a 16 port GBIC module (WS-X6516A-GBIC). What I thought would work was to remove the GBIC (G5486 LH/LX) along with the fiber connection and mount the GBIC in an available slot in the 6513. However the media type of the GIBC is now shown as LH instead of LX as was present in the 3508 and the link is shown as down/down I cannot find any indication that this can be controlled using console commands on the 6513. Has I missed something or do I have to get a new GBIC? As far as I know the other end of the fiber connection is out of my control. Our IOS is version 12.2(18)SXF3
If he moved the GBIC and fibres together then that wouldn't be a problem. Is a 3508 old enough not to do autonegotiation? If so he may have to configure the port on the 6513 - "speed nonegotiate" is the interface command, I think.
Fiber GBICs don't negotiate, at least I have never seen one that does, please correct me if I'm wrong, supporting documentation as well please. There are 2 different styles of GBICs, the original which had little release levers on the side, those you did not need to remove the fiber to remove the GBIC. Then there were these cheesy POS ones that had this stupid little wire type bar that you had to lift to remove them, on those you needed to remove the fibers. A GBIC is a GBIC is a GBIC, they work in all chassis, there is nothing platform/model specific about them. Never seen one fail (not saying they don't ). There are only a few things that can prevent them from coming up.
1, They need to be reversed.
2, The port is admin down (but then it would be amber).
3, The port is error disabled (never seen a fiber error disable, could be disabled if bpdugaurd was on).
4, Bad fiber, doubtful where this worked before, but I suppose the patch cable could have been damaged when it was moved.
Golly, no! The GigE standard says that you should always negotiate and if you fail then the interface doesn't come up. That's to prevent the duplex mismatches that plague 10/100M ethernet. Prestandard products, such as the Cisco 12000 family GigE boards don't negotiate so if you want to connect them to a 6500 then you have to turn off negotiation on the 6500. You then have to remember to turn negotiation back on again if you later connect that same 6500 interface to a standard device.
I don't have a reference to the standard but this is a clue:
The second type is an SFP (a Small Form factor Package GBIC, GBIC stands for something like GigaBit Interface Connector) and is much more commonly referred to that way.
Not true. Some Cisco platforms don't (or didn't) support at least one version of the Cisco 1000base-T GBIC (it takes a higher current than the optical ones). GBICs from different manufacturers cannot be reliably mixed (largely due to FUD, it seems). For instance a 3Com GBIC will probably work in a Cisco chassis but the type will not be reported correctly (it's always been blank when I've seen it) and a Cisco GBIC simply won't work in any of the 3Com switches we've tried them in (though 3Com have such a bewildering array of kit that I couldn't rule out them working in some). Here's some info:
Cisco GigaStack GBICs and other things are different again. There's a product overview page here:
Here's Cisco's policy on non-Cisco GBICs:
------------------------------------------------------------------------ Note: Cisco-approved GBIC modules have a serial EEPROM that contains the module serial number, the vendor name and ID, a unique security code, and cyclic redundancy check (CRC). When a GBIC is inserted in the switch, the switch software reads the EEPROM to check the serial number, vendor name and ID, and recompute the security code and CRC. If the serial number, the vendor name or ID, security code, or CRC is invalid, the switch places the interface in an error-disabled state.
------------------------------------------------------------------------ Note: If you are using a non-Cisco approved GBIC module, remove the GBIC module from the switch, and replace it with a Cisco-approved module.
OK, I've never seen a traditional GBIC with a wire latch.
SFPs definitely have them, and in several places [1] SFPs are referred to as "Small Form-Factor Pluggable (SFP) GBIC Module" (yes, Pluggable not Package - sorry). So SFPs *are* GBICs with a "stupid little wire type bar that you [have] to lift to remove them". :-)
Sam
[1] here are a few - Google for "SFP GBIC" to find lots more:
This is an interesting topic/conversation to me, please don't take anything I'm saying wrong. I would love to be proven wrong on this and find a way to bring up legacy customers shy of using media converters. I do not believe the FIBER GBICs (we are talking what the OP has,
5484's, 5486's or 5487's) follow the GigE standard, these might have even been before the standard. Again, I believe that their speed/duplex cannot be changed at all. They are 1000, that's it, plain and simple. I have done numerous searches on them and all I see mentioned is 1000base. I also just tried this is a lab, going from a 3550 with a 5484gbic to an old 2924M with a 100M fiber port, the link will not come up. While this sure as heck isn't definative, it does support my thinking. You can google groups on people trying to bring up new switches to their older devices which were only 100M. One thingthat I am finding which supports your statements is that they do support the speed nonegotiate command, but my thinking here is that it is nonnegotiate for flow control, not speed as indicated by the "speed" in the actual command. Another supporting tidbit is the fact that there is no duplex settings to manipulate, if it did follow the standards that should be a configurable parameter as well.
Again, was refering to what the OP has which are 5484's, 5486's or 5487's. He came from a 3508 there are no other fiber GBIC's available for it.
Was refering to yet again what the OP has, not SFP's, not GigsStacks. They are Cisco GBIC's, not 3com, extreme foundry or anyone else. They are not platform independant and are a standard accross all of their platforms that accept that size/model GBIC.
I was strictly refering to what the OP had. There are tons of different model GBIC's out there. I should have been more clearer (great english huh? LOL).
I can shoot ya a pic if you'd like! I hate these friggin things! Got a few of them here in my lab. I'll trade you for some of the other ones so you can experience them first hand!
I worked with GBICs extensively about 7 years ago and at that time there were quite a few failures.
As to the autonegotiation issue. As far as I know Fiber Optic Ethernet ports each only offer a single speed.
In the 10 and 100 days this was because the different standards specified quite different wavelengths and the physical optics and devices had to be different.
I don't know how GBE is vs the others though.
Constraining a port to a single speed though does not prevent it Autonegotiating. That is exchanging mesages about capability with its neighbour.
In the Fibre Optic GBE case they will both say 1000 FD and then they will happily go to work.
comp.dcom.lans.ethernet may have something or if you ask a question there Mr Seifert may be around or you could buy his book/get the IEEE Standard.
My guess is that the Standards committee may have made Autonegotiation compulsory even though in some cases it is never going to be needed in order to simplify the Standard. I don't, I hasten to add, know.
It is in the same veign interesting to note that the GBE standard included Half Duplex operation as a possibility however I believe that HD implementations are non-existent. I suspect that the Cisco Stacking GBIC is HD but it is intended to interoperate only with others of its kind and as such may not follow any standards at all.
OK, let me clarify. The negotiation is done by the GigE interface logic and is basically independent of the kind of GBIC or other PHY installed. I agree that most, if not all, GBIC based GigE systems don't negotiate speed, but they do negotiate duplex and flow control. (It turns out that 1000base-T systems cannot operate without negotiation turned on; other 1000base-X systems have it on be default but are allowed by the standard to have it configured off.) Here's a description for CatOS but there ought to similar things in the IOS manuals:
In the example we have here there is a 6500 with a standard Cisco
1000base-SX GBIC (that'll be a 5484) connecting to a Cisco 12000 1-port GigE interface. That also has a GBIC but according to the C12000 data sheets it seems to be a special part. No change of speed (or duplex) but we do have to turn of negotiation to make the link come up.
Yes - agree. Apologies if I misled you.
Yes. From the URL above:
"With Gigabit Ethernet ports, autonegotiation is used to exchange ... duplex information (even though Cisco Gigabit Ethernet ports only support full-duplex mode)."
OK, the second type isn't an SFP. :-) But none of the 54xx series has the wire latch, does it?
I missed the OP saying 5484/6/7. Those do seem to be interchangeable (see that URL above) but there are lots of others that Cisco make or made that aren't, so in general a GBIC, even a Cisco one, is not a GBIC is not a GBIC.
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