The Logical Tunnel Interface for Juniper

The summary of Juniper Virtual-Router are confirm can run dynamic routing-protocols, OSPF, BGP and packet capture between them use 'monitor traffic'. Communication between Virtual-Router use physical cable loop (jumper). There are a few different way to leak traffic between Virtual-Router logically. The one of them is logical tunnel interface, LT need little config to connect between Virtual-Router.

Please find the example logical tunnel interface, Please check also mini Lab OSPF use physical cable between them, I will add logical interface with that config as pre-config.


#### Create Logical Tunnel Interface
set interfaces lt-0/0/0 unit 10 description "to R1 lt-0/0/0.11 logical tunnel"
set interfaces lt-0/0/0 unit 10 encapsulation ethernet
set interfaces lt-0/0/0 unit 10 peer-unit 11
set interfaces lt-0/0/0 unit 10 family inet address 172.16.11.10/24

set interfaces lt-0/0/0 unit 11 description "to R0 lt-0/0/0.10 logical tunnel"
set interfaces lt-0/0/0 unit 11 encapsulation ethernet
set interfaces lt-0/0/0 unit 11 peer-unit 10
set interfaces lt-0/0/0 unit 11 family inet address 172.16.11.11/24

#### R0
set routing-instances R0 interface lt-0/0/0.10

#### R1
set routing-instances R1 interface lt-0/0/0.11

#### Verify and Ping Test
user@JunOS> ping routing-instance R0 172.16.11.11 source 172.16.11.10 rapid    
PING 172.16.11.11 (172.16.11.11): 56 data bytes
!!!!!
--- 172.16.11.11 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 3.002/3.867/4.676/0.686 ms

user@JunOS> ping routing-instance R1 172.16.11.10 source 172.16.11.11 rapid    
PING 172.16.11.10 (172.16.11.10): 56 data bytes
!!!!!
--- 172.16.11.10 ping statistics ---
5 packets transmitted, 5 packets received, 0% packet loss
round-trip min/avg/max/stddev = 3.088/5.639/9.520/2.867 ms

user@JunOS> show arp 
MAC Address       Address         Name                      Interface     Flags
b0:c6:9a:xx:yy:00 172.16.1.10     172.16.1.10               ge-0/0/1.0    none
b0:c6:9a:xx:yy:01 172.16.1.11     172.16.1.11               ge-0/0/0.0    none
b0:c6:9a:xx:yy:00 172.16.11.10    172.16.11.10              lt-0/0/0.11   none
b0:c6:9a:xx:yy:01 172.16.11.11    172.16.11.11              lt-0/0/0.10   none
Total entries: 4


What's next ?
I will join new interface to OSPF instance.
Please stay tune :-)


#### OSPF between R0 and R1
user@JunOS> edit 
Entering configuration mode

[edit]
user@JunOS# set routing-instances R0 protocols ospf area 0.0.0.0 interface lt-0/0/0.10 

[edit]
user@JunOS# set routing-instances R1 protocols ospf area 0.0.0.0 interface lt-0/0/0.11    

[edit]
user@JunOS# show | compare 
[edit routing-instances R0 protocols ospf area 0.0.0.0]
        interface ge-0/0/0.0 { ... }
+       interface lt-0/0/0.10;
[edit routing-instances R1 protocols ospf area 0.0.0.0]
        interface ge-0/0/1.0 { ... }
+       interface lt-0/0/0.11;

[edit]
user@JunOS# commit 
commit complete

[edit]
user@JunOS# 

#### Verify OSPF
user@JunOS> show ospf neighbor instance all              
Instance: R0
Address          Interface              State     ID               Pri  Dead
172.16.1.11      ge-0/0/0.0             Full      172.16.1.11      128    39
172.16.11.11     lt-0/0/0.10            Full      172.16.1.11      128    36

Instance: R1
Address          Interface              State     ID               Pri  Dead
172.16.1.10      ge-0/0/1.0             Full      172.16.1.10      128    31
172.16.11.10     lt-0/0/0.11            Full      172.16.1.10      128    37

user@JunOS> show ospf interface instance R0 detail    
Interface           State   Area            DR ID           BDR ID          Nbrs
ge-0/0/0.0          BDR     0.0.0.0         172.16.1.11     172.16.1.10        1
  Type: LAN, Address: 172.16.1.10, Mask: 255.255.255.0, MTU: 1500, Cost: 1
  DR addr: 172.16.1.11, BDR addr: 172.16.1.10, Priority: 128
  Adj count: 1
  Hello: 10, Dead: 40, ReXmit: 5, Not Stub
  Auth type: None
  Protection type: None
  Topology default (ID 0) -> Cost: 0
lt-0/0/0.10         BDR     0.0.0.0         172.16.1.11     172.16.1.10        1
  Type: LAN, Address: 172.16.11.10, Mask: 255.255.255.0, MTU: 1500, Cost: 1
  DR addr: 172.16.11.11, BDR addr: 172.16.11.10, Priority: 128
  Adj count: 1
  Hello: 10, Dead: 40, ReXmit: 5, Not Stub
  Auth type: None
  Protection type: None
  Topology default (ID 0) -> Cost: 0

user@JunOS> show ospf interface instance R1 detail    
Interface           State   Area            DR ID           BDR ID          Nbrs
ge-0/0/1.0          DR      0.0.0.0         172.16.1.11     172.16.1.10        1
  Type: LAN, Address: 172.16.1.11, Mask: 255.255.255.0, MTU: 1500, Cost: 1
  DR addr: 172.16.1.11, BDR addr: 172.16.1.10, Priority: 128
  Adj count: 1
  Hello: 10, Dead: 40, ReXmit: 5, Not Stub
  Auth type: None
  Protection type: None
  Topology default (ID 0) -> Cost: 0
lt-0/0/0.11         DR      0.0.0.0         172.16.1.11     172.16.1.10        1
  Type: LAN, Address: 172.16.11.11, Mask: 255.255.255.0, MTU: 1500, Cost: 1
  DR addr: 172.16.11.11, BDR addr: 172.16.11.10, Priority: 128
  Adj count: 1
  Hello: 10, Dead: 40, ReXmit: 5, Not Stub
  Auth type: None
  Protection type: None
  Topology default (ID 0) -> Cost: 0