Benjamin, Your note made me realize there are multiple levels of autonegotiation that I had no idea even existed. I see a wikipedia spiral in my future!
Thanks for the recap. Norman On Sun, May 10, 2020 at 9:55 AM Benjamin Collet <juniper-...@clt.tf> wrote: > > Hi, > > On Tue, May 05, 2020 at 08:42:20PM +0200, Gert Doering wrote: > > > We've long standardized on running autonegotiation, everywhere. Do > > > others actually disable autonegotiation on "managed" connections, > > > where you're configuring both ends of the link? > > > > Devices or Carriers disabling autoneg are a major PITA and need to > > rot in hell. It's a mandatory part of the standard and should be > > treated as such. > > > > (So, no, we never disable autoneg unless talking to something stupid) > > Actually it's only mandatory on 1000Base-TX. > > The thing is that auto-negotiation on 1000Base-X includes link fault > signaling, which is great... and not a mandatory part of the 1000Base-X > standard, albeit often implemented. > > It is not an issue as long as the remote party implements > auto-negotiation on 1000Base-X (which is optional) and link fault > signaling (which is an optional part of auto-negotiation) and doesn't > use an SGMII-based transceiver as they don't support link fault signaling > (I don't know about RGMII-based transceivers but I wouldn't bet on them > having the management interface for it). > > In the unlikely (right?) event that the aforementioned conditions are > not met, for the link to go up, one solution is to disable > auto-negotiation entirely. Another one is to play with the > `auto-negotiation remote-fault` knob if you're using a MX/ACX device > (good luck understanding the documentation on that one). > > I am not advocating for disabling auto-neg (and link fault signaling) on > 1G fibre links, on the contrary, but there are good and valid reasons to > do so. > > Benjamin > -- > Benjamin Collet > _______________________________________________ > juniper-nsp mailing list juniper-nsp@puck.nether.net > https://puck.nether.net/mailman/listinfo/juniper-nsp _______________________________________________ juniper-nsp mailing list juniper-nsp@puck.nether.net https://puck.nether.net/mailman/listinfo/juniper-nsp
