I was told the same. Seems it is in the standard.
----- Original Message ----- From: Ken Hohhof To: [email protected] Sent: Friday, July 31, 2015 11:15 AM Subject: Re: [AFMUG] Tik - Cisco SFP I don’t know about SFP, but I was told GigE should always be set to auto. “It would be bad.” - Dr. Egon Spengler From: Faisal Imtiaz Sent: Friday, July 31, 2015 11:01 AM To: [email protected] Subject: Re: [AFMUG] Tik - Cisco SFP Exactly......... Moral of the story... when using two boxes from two different mfg. do not rely on auto negotiate.... Hard Code.... is the preferred choice.. Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] ------------------------------------------------------------------------------ From: "Glen Waldrop" <[email protected]> To: [email protected] Sent: Friday, July 31, 2015 10:42:39 AM Subject: Re: [AFMUG] Tik - Cisco SFP We've had different results. I built an x86 router with MT running an Intel fiber adapter. Works like a charm. No issues whatsoever. Bossman is certain a CCR1036 is faster than a Core i7, so he replaced the x86 box. CCR would not link up to the existing fiber unless I manually set the speed and duplex. It did have that problem on any gigabit link, so it may have primarily been an autonegotiate problem in that particular case. We did have problems with an SFP in a 2011 as well. Worked fine connecting from a CCR to a 2011. Not so well connecting to anything Cisco and whatever brand converter AT&T used. Can't remember at the moment. Coffee isn't working yet. ----- Original Message ----- From: Faisal Imtiaz To: [email protected] Sent: Friday, July 31, 2015 9:24 AM Subject: Re: [AFMUG] Tik - Cisco SFP Hmm... this is rather strange... In future keep some of these troubleshooting tips in mind.. 1. You have to make sure that type of SFP & (Wavelength) Matches.. i.e. MM --> MM SFM --> SMF , SMF can be 1310 or 1550 make sure both sides match 2. Make sure light is reaching both sides... use a light meter (if you don't have one, consider buying one .. approx $50 from Fiberstore.com) if you don't have a light meter, you can use use a far side loop back (simply connect the Rx side to Tx side on the far side) you can use this method to test each side coming up individually. 3. Make sure that if you are using SFP of correct ratings (i.e. 1gig in the 1gig ports) Not all SFP+ (10G) will accept 1G SFP's. 4. Make sure the Duplex Settings match on each side... for Cisco, it is best to hard code each side. 5. When using SMF SFP's, it is possible to over load the receiver, i.e. getting too much light... and not have link.... in such cases it is ideal to use a 'pad' or attenuator. This is the reason why it is important to have a light meter... Having said that... I have yet to come across a situation where one SFP will not connect to another SFP as long as all of the other above listed reason are not the cause of the problem.. If you are worried about testing compatibility.... easiest thing to do is use a fiber patch cord (LC-LC) to create yourself a loop back cable (you can add a 3db attenuator if you like), plug in the SFP in your device, make sure that the device will see the SFP, connect the loop back cable and the link should come up... (if you need to make field attenuator... do some googling on how to wrap fiber cable strand tightly around a #2 pencil to create one) :) Faisal Imtiaz Snappy Internet & Telecom 7266 SW 48 Street Miami, FL 33155 Tel: 305 663 5518 x 232 Help-desk: (305)663-5518 Option 2 or Email: [email protected] -------------------------------------------------------------------------- From: "Jason McKemie" <[email protected]> To: [email protected] Sent: Thursday, July 30, 2015 11:43:43 PM Subject: Re: [AFMUG] Tik - Cisco SFP I tried to get a couple mikrotiks to talk to a Cisco nexus switch at the other end of some dark fiber. We couldn't get anything to work - showed as up on my end, but down on the Cisco end. Wound up dropping a Cisco router in place of the tik and it came right up. On Thursday, July 30, 2015, Tyler Treat <[email protected]> wrote: Does anyone have a recommended SFP for going from a 2011 to a Cisco Switch? Anything special to be aware of? Thanks Tyler
