[j-nsp] Correct config for SRX port channel -> Cisco

[Phil Mayers]

If I have a single SRX3600 device (NOT a cluster), what config (if 
any...) can I use to match a config on the Cisco side:

int <member>
   lacp rate fast
   channel-group 20 mode active
int Po20
   switchport
   switchport mode trunk
   switchport trunk allowed vlan 999
int Vlan999
   ip address 192.168.1.1 255.255.255.254

I would have thought it would be something like:

chassis {
     aggregated-devices {
         ethernet {
             device-count 2;
         }
     }
}
interfaces {
     xe-1/0/0 {
         gigether-options {
             802.3ad ae0;
         }
     }
     xe-1/0/1 {
         disable;
     }
     xe-4/0/0 {
         gigether-options {
             802.3ad ae0;
         }
     }
     xe-4/0/1 {
         disable;
     }
     ae0 {
         vlan-tagging;
         aggregated-ether-options {
             lacp {
                 active;
                 periodic fast;
             }
         }
         unit 999 {
             vlan-id 999;
             family inet {
                 address 192.168.1.2/31;
             }
         }
     }
}

...but this never comes up. I've seen this before, and I think it's 
because there's something in the LACP PDUs which disagrees about 
trunk/access mode. The config works if I set the Cisco side to "access", 
but obviously that's not what I want.

Can you even do this on SRX? I see lots of documents talking about reth 
interfaces, but AFAICT those are all for chassis clustering, which we 
don't want to use.