One of the beauties of Jumiper SRX is it has a heritage function from ScreenOS called “virtual router”. Unlike ScreenOS, Junos has the ability link virtual routers up with logical interfaces (lt-0/0/0). With these 2 features, Virtual routers could have their own route tables, could simulate several routers within a single box of SRX, and could run routing protocols between them. (I have tried with Cisco VRF, but it doesn’t work as expected.)

From the official specification from Juniper, SRX 100 should only support 3 virtual routers. The secret here is SRX 100 h2 version could create up to 11 virtual routers, and all of them can run flawlessly. (Juniper s not selling any non SRX100 h2 from a year ago. So a single SRX could do the OSPF, OSPF v3, IS-IS and limited BGP training lab already.)
Since my SRX is my internet gateway with NAT, it runs with flow mode. But the VRs will be run as stateless mode by applying packet filter to avoid any policy restrictions blocking the OSPF talks and asymmetric flows between VRs. (If any questions regarding to this configuration, feel free to let me know. )

This post will focus on OSPF with IPv4 only. The topology for OSPF lab is listed as below. (This test bed is being used for Internet access and for my BGP labs too.)
There will be 9 virtual routers and 3 VRs at the centre serve as backbone and ABR, other VRs will be connecting to the backbone VRs. (With enough creativity and skills, you could use this test bed to learn the characteristic and behaviors of different OSPF area types.)

 

The OSPF lab for this time will be a simple flat layer with all routers placed in area 0. Putting everything in area 0 allows network administrators to handle their network easily without too much of the troubleshooting needs if the network does not have much of the changes frequently. However, it would not be a good practice if network is expending as all high and low end OSPF member routers require to consume have as much memories when they have to share the same size of route table amount each others.  (We will talk about that in another post.)

Configuration:
I will describe the configuration for VR-001 as the example. Other similar VR configuration will simply be pasted below.

A trimmed OSPF datebase report from VR-001. It shows all of the virtual routers are in the OSPF area 0.

OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
 Router  *192.168.201.1    192.168.201.1    0x80000004   320  0x22 0x6f9f 180
 Router   192.168.201.2    192.168.201.2    0x80000004   321  0x22 0xec0f 180
 Router   192.168.201.3    192.168.201.3    0x80000004   320  0x22 0xd018 180
 Summary *192.168.201.11   192.168.201.1    0x80000001   315  0x22 0x3198  28
 Summary *192.168.201.12   192.168.201.1    0x80000001   315  0x22 0x27a1  28
 Summary  192.168.201.21   192.168.201.2    0x80000001   320  0x22 0xc6f7  28
 Summary  192.168.201.22   192.168.201.2    0x80000001   320  0x22 0xbc01  28
 Summary  192.168.201.31   192.168.201.3    0x80000001   316  0x22 0x5c57  28
 Summary  192.168.201.32   192.168.201.3    0x80000001   320  0x22 0x5260  28

[edit]

Summary:
The configuration above (in my case) should have enough virtual routers to create a test bed for OSPF. Later on there will be some more post about putting VRs into different types of ospf area, such as stub, NSSA, and totally stub at the test bed.
Hope this post could give out an idea to those who is low on budget of setting up a home lab for learning, regardless of using VM. Please share it out if you like this post.