i got it to work.... I was able to add lt interface (logical tunnel interface) as layer 2 interfaces into a routing-instance virtual-switch bridge-domain and then add irb on each logical system and ping across. below i show config and outputs for show commands of pings, bridge entries, arp caches, and different mac address needed for each irb
r6@lab-mx104:r6> show configuration | display set
...
set logical-systems r6 interfaces lt-0/1/0 unit 670 description r6->r7_1
set logical-systems r6 interfaces lt-0/1/0 unit 670 encapsulation ethernet-bridge
set logical-systems r6 interfaces lt-0/1/0 unit 670 peer-unit 760
set logical-systems r6 interfaces lt-0/1/0 unit 670 family bridge interface-mode access
set logical-systems r6 interfaces lt-0/1/0 unit 670 family bridge vlan-id 10
set logical-systems r6 interfaces irb unit 6 family inet address 172.16.40.2/24
set logical-systems r6 interfaces irb unit 6 mac 00:00:00:00:00:06
set logical-systems r6 routing-instances switch1 instance-type virtual-switch
set logical-systems r6 routing-instances switch1 interface lt-0/1/0.670
set logical-systems r6 routing-instances switch1 bridge-domains switch1 vlan-id 10
set logical-systems r6 routing-instances switch1 bridge-domains switch1 routing-interface irb.6
r7@lab-mx104:r7> show configuration | display set
...
set logical-systems r7 interfaces lt-0/1/0 unit 760 description r7->r6_1
set logical-systems r7 interfaces lt-0/1/0 unit 760 encapsulation ethernet-bridge
set logical-systems r7 interfaces lt-0/1/0 unit 760 peer-unit 670
set logical-systems r7 interfaces lt-0/1/0 unit 760 family bridge interface-mode access
set logical-systems r7 interfaces lt-0/1/0 unit 760 family bridge vlan-id 10
set logical-systems r7 interfaces irb unit 7 family inet address 172.16.40.3/24
set logical-systems r7 interfaces irb unit 7 mac 00:00:00:00:00:07
set logical-systems r7 routing-instances switch1 instance-type virtual-switch
set logical-systems r7 routing-instances switch1 interface lt-0/1/0.760
set logical-systems r7 routing-instances switch1 bridge-domains switch1 vlan-id 10
set logical-systems r7 routing-instances switch1 bridge-domains switch1 routing-interface irb.7
r6 shows...
r6@lab-mx104:r6> ping 172.16.40.3 rapid
PING 172.16.40.3 (172.16.40.3): 56 data bytes
!!!!!
--- 172.16.40.3 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.492/0.558/0.703/0.076 ms
r6@lab-mx104:r6> show interfaces irb.6 | grep "inet|mac"
MAC: 00:00:00:00:00:06
Protocol inet, MTU: 1514
r6@lab-mx104:r6> show arp interface irb.6
MAC Address Address Name Interface Flags
00:00:00:00:00:07 172.16.40.3 172.16.40.3 irb.6 [lt-0/1/0.670] none
r6@lab-mx104:r6> show bridge mac-table
MAC flags (S -static MAC, D -dynamic MAC, L -locally learned, C -Control MAC
O -OVSDB MAC, SE -Statistics enabled, NM -Non configured MAC, R -Remote PE MAC)
Logical system : r6
Routing instance : switch1
Bridging domain : switch1, VLAN : 10
MAC MAC Logical NH RTR
addresssss flags interface Index ID
00:00:00:00:00:07 D lt-0/1/0.670
30:b6:4f:68:70:a9 S,NM lt-0/1/0.670
r7 shows...
r7@lab-mx104:r7> ping 172.16.40.2 rapid
PING 172.16.40.2 (172.16.40.2): 56 data bytes
!!!!!
--- 172.16.40.2 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.485/0.573/0.714/0.082 ms
r7@lab-mx104:r7> show interfaces irb.7 | grep "inet|mac"
MAC: 00:00:00:00:00:07
Protocol inet, MTU: 1514
r7@lab-mx104:r7> show arp interface irb.7
MAC Address Address Name Interface Flags
00:00:00:00:00:06 172.16.40.2 172.16.40.2 irb.7 [lt-0/1/0.760] none
r7@lab-mx104:r7> show bridge mac-table
MAC flags (S -static MAC, D -dynamic MAC, L -locally learned, C -Control MAC
O -OVSDB MAC, SE -Statistics enabled, NM -Non configured MAC, R -Remote PE MAC)
Logical system : r7
Routing instance : switch1
Bridging domain : switch1, VLAN : 10
MAC MAC Logical NH RTR
addresssss flags interface Index ID
00:00:00:00:00:06 D lt-0/1/0.760