Hi, Here is the public documentation of MX304 mentioning the MTU limitation for 1G: https://www.juniper.net/documentation/us/en/software/junos/interfaces-ethernet/topics/ref/statement/speed-gigether-options.html
* On MX304 for 1G interface, the maximum MTU supported is 2000 bytes. Hence, the maximum MRU supported is 2008 bytes. Br., -- Eduardo Haro Juniper Business Use Only From: juniper-nsp <juniper-nsp-boun...@puck.nether.net> on behalf of Ola Thoresen via juniper-nsp <juniper-nsp@puck.nether.net> Date: Friday, 3 November 2023 12:16 To: juniper-nsp@puck.nether.net <juniper-nsp@puck.nether.net> Subject: Re: [j-nsp] QSA adapters and MTU [External Email. Be cautious of content] On 03.11.2023 16:04, Chris Wopat wrote: > We use them on MX304 at 10g, primarily to get DWDM SFP+ to work. MTU > is fine, it's 9k as a part of LACP on a recent deployment. The adapter > simply passes through lane :0 to the port when configured as QSFP+. If > you insert the adapter and no optic, the device is unaware of its > existence - you only see the SFP+ info. > This is the same use case as for us, and my understanding is exactly that they are just passing a single lane through, and should not really know anything about packets or ethernet frames or anything. But still - people more knowledgeable than me - assure me that there is a limit of 2008 Bytes MTU - at least for 1G. I just can't find this documented anywhere, and I would have thought that more people would have made more fuss about it when they start using it if this is a real issue. > We haven't tested in prod on 1g but i think we did in the lab. can > probably toss something in there if you're really curious. I think the > juniper supported optic page lists QSA adapter support or not. I > thought it was generally supported with Junos 20+ nowadays. > Yes. They list QSA adapter as supported, also for 1G optics, and don't write anything about any MTU limitations in the Hardware Compatibility Tool. /Ola (T) _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://urldefense.com/v3/__https://puck.nether.net/mailman/listinfo/juniper-nsp__;!!NEt6yMaO-gk!DaqgnffXeN_5g5MT4MX8vxG5xhtjRSbu8HSfaHQe_k3qfrESOCfV3YpaMzwMEdc7T8gs6JHvNYaXKmVMAI16rgk$<https://urldefense.com/v3/__https:/puck.nether.net/mailman/listinfo/juniper-nsp__;!!NEt6yMaO-gk!DaqgnffXeN_5g5MT4MX8vxG5xhtjRSbu8HSfaHQe_k3qfrESOCfV3YpaMzwMEdc7T8gs6JHvNYaXKmVMAI16rgk$> _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
