That's what I was going to chime in on. Behaviour differences between software versions have done different defaults.
ekrichbaum@atl-bdr1> show interfaces et-0/0/1 | grep FEC Active defects : None Ethernet FEC Mode : NONE eric@cht-bdr2> show interfaces et-0/0/1 | grep FEC Active defects : None Ethernet FEC Mode : FEC91 These are 204s with a difference in default from 17.4 to 18.2 somewhere. Manually setting FEC on both ends seems to correct and bring up the links. -----Original Message----- From: juniper-nsp <[email protected]> On Behalf Of Tobias Heister Sent: Friday, June 12, 2020 2:03 PM To: [email protected] Subject: Re: [j-nsp] MX routers and DAC cables? Hi, On 12.06.2020 20:39, Chris Adams wrote: > Is anybody using DAC cables on MX routers? We have a customer with an > MX10003 connected to EX4600 switches with 40G DAC cables (Juniper > parts, not third-party). Upon upgrading the router JUNOS to > 18.2R3-S3, none of the interfaces with a DAC cable would come up on the router end. > > JTAC's response was that no DAC cables are supported on any MX routers. > > That seems a little odd to me... I thought DAC cables are a part of > the various specs, so saying they're not supported is saying those > aren't actually Ethernet ports to me. DAC and AOC are transceivers, and officially only a specific set of transceivers are supported per platform. For MX10003 you can check here: https://apps.juniper.net/hct/product/#prd=MX10003 There are 40GE AOC supported for that box, but not 40GE DAC. For 100GE DAC are actually supported in later Junos version. That being said typically DAC worked in MX for 10G and even 40G on most noxes, but on MX10003 we had a lot of problems with 40G DACs and eventually replaced most/all of of them with optical transceivers. Even on 100GE you might need to set the FEC config depending on what and where you connect the other DAC end. While 10G mostly worked everywhere we had a fair share of trouble on 40 and 100GE on various vendors and platforms. -- regards Tobias _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus _______________________________________________ juniper-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/juniper-nsp
