[j-nsp] Force ports with only RX connected to UP

[John Wilkes]

Hi.

We have a bunch of fiber taps that we want to aggregate in a Juniper
EX4200 (24 SFP) before sending it to our network analyzer.

What we thought we would do is connect all the taps to port 0 to X and
then mirror the traffic from them to port 23.

Problem: We don't get link up when we only connect to RX. It seems the
switch really really wants to talk to someone on the other end.

We have disabled autoneg, set full duplex 1G, and even turned off flow
control but the ports are still down. We have also reduced the problem
to connecting two ports directly.

When the ports are fully connected they come up. Pull just one fiber
and both ports go down.

We have tried turning off lldp, stp, rstp and mstp globally on the
switch, as well as setting half duplex.

Both ports are configured thus:

root# show interfaces ge-0/0/12
ether-options {
    no-auto-negotiation;
    no-flow-control;
    link-mode full-duplex;
    speed {
        1g;
    }
}
unit 0 {
    family ethernet-switching;
}


How do we get these ports up and receiving?