VRF Lite Configuration on Cisco IOS

Lessons Discussion
21

Hi Rene,

Thanks for your kind supports. Actually, I’d like to see just example for this two method ASAP.

22

I really like this. I’m thinking of using this for a Layer3 OOB Mngmt network. With VRF lite I won’t have asymmetric routes all over the place.

23

Excellent Presentation!! I used to think VRF was complex but I see it is actually pretty simple. Thanks for the Lecture.

24

Hi Rene,

I have 3 routers connected back to back R1 and R2 connected with Multi link on S0/2/0 and 0/2/1 ( Multilink1 and Multilink2) from R2 S 0/2/2 connected to R3 S 0/2/2, R3 S0/2/3 connected to R1 S 0/2/3.

R1 is running OSPF and BGP

R2 and R3 running BGP

i got task to implement VRF on this.

Could you please help here

25

MadhuSudana,
If you have a specific question we can try to help, but in general, we do not do people’s homework or design their networks.

--Andrew

26

Hi Rene!

How do VRFs work with EIGRP? I am trying to configure it with the same topology and it’s not working. Here’s the partial config of ISP trying to connect to Blue1. The VRF name I have for Blue’s is UPPER.

router eigrp 10
 no auto-summary
 !
 address-family ipv4 vrf UPPER
 network 192.168.1.254 0.0.0.0
 no auto-summary
 exit-address-family

Please help!

Thanks!

-=UPDATE=-

fixed it! I have to add ‘autonomous system x’ to the address-family

3 Likes
27

Hi Rene,

I could understand vrf concept, but What is vrflite, and where it will be used ?

28

Hi Rohitendu,

VRF-lite is using VRFs without MPLS. You use VRFs in networks where you need routing/traffic isolated, such as VLANs at layer 2. For example, universities and health care networks typically have VRFs to comply with security standards.

Hope that answers your question!

29

Hi Jesse L,

It means if we use GRE in core for forwarding IP packets in place of MPLS(RFC 2547 bis) then those vrfs are called VRF-LITE ?
pls correct me

30

Hi,

Did you see this example?

VRF Lite

Basically a VRF is nothing more but having multiple routing tables instead of one global routing table.

When we use VRFs without MPLS, we call it VRF “lite”.

Rene

1 Like
31

Hi Rene,

Thanks for the post. I had a simple question:

What is the difference between the following configuration:

1)     router ospf 1 vrf SALES
           network 5.0.0.0 0.0.0.255 area 0

2)     router ospf 1
           address-family ipv4 vrf SALES
           network 5.0.0.0 0.0.0.255 area 0

How are these two different?

Thanks.

32

Parth,
What version of IOS are you using? I don’t believe your second item is an option.

Here’s the output from my IOS 15 code:

R10(config-router)#address-family ipv4 ?
  multicast  Address Family modifier

Notice that the only option after address-family ipv4 is “multicast”

33

Hi Rene,

Thank you for great explaination.

Editing the question. I have seen the Easy VPN cofiguration with two ISP routers .
But here we have only one ISP router. what would be the configurations required on this single ISP router in order to communicate between VRF’s.

I have understood how to configure with two ISP routers but was little confused with configurations for Different VRF configurations with one ISProuter.

Regards,
A.

34

Hi A,

Did you also see some of my MPLS PE CE examples? Like this one:

https://networklessons.com/rip/mpls-layer-3-vpn-pe-ce-rip/

Even with a single router that is using VRFs, you can use the same logic. We can use route-targets to import/export routes and let BGP do the redistribution.

If you need an example, let me know.

Rene

35

19 posts were merged into an existing topic: VRF Lite Configuration on Cisco IOS

37

Hello Laz,
One question. routing-context vrf ABC can be used to go under that specific vrf ABC. I thought as long as I am under the context, whatever I do will be applied for that vrf, but that is not the case. As an example, if I create a default route while I am under the context, it goes for the default routing table. In order to create a vrf specific default static route, vrf name has to be specified in the command. Now the question is what are the use cases to use routing-context vrf----- command. I know it sounds kind of goofy, but I looked for some satisfactory explanation but I did not find one.

Thank you in advance.

Azm

38

Hi Azm,

Routing context for VRFs only applies to EXEC commands like ping or telnet. It is a bit confusing since it still shows up when you enter config mode:

R1#routing-context vrf RED
R1%RED#conf t
R1%RED(config)#

Technically, I could use an EXEC command from the config mode though:

R1%RED(config)#do ping 192.168.12.2
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 192.168.12.2, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 6/6/7 ms

Which sends a ping from VRF RED. Just keep in mind it only works for EXEC commands.

1 Like
39

Thanks a lot Rene…

Azm

40

Hi Rene,

In single Router Scenario that you showed your tutorial , Is possible to exchange prefix/Communication from one VRF to other VRF Like Red to Blur or vice versa . Thx

br//zaman

41

Hello Zaman.

Yes it is possible to exchange information between VRFs. This should be done carefully however. Take a look at this Cisco support forum thread that will probably clear it up for you. If you have additional questions, let us know!

I hope this has been helpful!

Laz