Integrated Routing and Bridging (IRB) on juniper router to achieve redundancy

Summary: 

Today i had a network scenario where two SBCs (Session Border Controllers) were supposed to connect to one router. The SBCs are from oracle and the router which is going to function as my border gateway router is a juniper MX5.

The SBCs are supposed to work in active/standby mode and are running VRRP between them selves. VRRP is Virtual Router Redundancy Protocol.
In this case the virtual IP will floating between the two SBCs depending on whichever is active.

Below is a summary of my setup:

Integrated Routing and Bridging

Problem or Goal:

From the router, we should be able to ping the active SBC, the virtual IP is always resident on the active SBC and we should be able to ping it from the router even if the SBCs switch positions.

Cause:

This is a common scenario, you find yourself in a situation where you have servers working in active/standby mode connected to one router yet you need to achieve redundancy. 

Solution:

For this to workout, the SBCs and the router interfaces need to be in one broadcast domain, so we are going to bridge the two router interfaces into one bridge domain using a technique called IRB (Integrated Routing and Bridging).

our IP plan is as below:

Network:   10.10.10.0/29           
Netmask:   255.255.255.248  
Wildcard:  0.0.0.7                      
Broadcast: 10.10.10.7            
HostMin:   10.10.10.1           
HostMax:   10.10.10.6            
Hosts/Net: 6   

The /29 gives us 6 IPs, 3 of the IPs will be used for the VRRP configuration on the SBCs, we shall need only one IP at the router side since we are using only one router. we shall use vlan 100 on both the router and the SBCs.

Below is the quick configuration:

set interfaces ge-1/0/0 description To_SBC01
set interfaces ge-1/1/0 description To_SBC02
set interfaces ge-1/0/0 vlan-tagging
set interfaces ge-1/1/0 vlan-tagging
set interfaces ge-1/0/0 unit 0 family bridge interface-mode trunk
set interfaces ge-1/1/0 unit 0 family bridge interface-mode trunk
set interfaces ge-1/0/0 unit 0 family bridge vlan-id-list 100
set interfaces ge-1/1/0 unit 0 family bridge vlan-id-list 100

set bridge-domains SBC domain-type bridge
set bridge-domains SBC vlan-id 100
set bridge-domains SBC routing-interface irb.100

set interfaces irb unit 100 description Connects_To_SBC
set interfaces irb unit 100 family inet address 10.10.10.4/29

Problem Solved?

Yes, from the router, am able to ping the virtual IP which is resident on whichever SBC is active. 

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