GRE Tunnel Basic

Hi Rene:
First of all, thanks for the lab. I'm trying to do it but I have some problemas with the tunneling. Could you put the routers configuration in order to check my solution?
Thanks in advance,

Hi Luis,

Do you still have your configs? drop them here and i'll take a look.

Hi Rene, Thanks for the lab and congratulation for the page. Could you check it? If I can see the network 33.33.33.0/24 know by a OSPF update, I guess is work right? Thanks for your time

Godzilla#sh ip route

Gateway of last resort is not set

C 192.168.12.0/24 is directly connected, FastEthernet0/0
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
C 192.168.13.0/24 is directly connected, Tunnel0
33.0.0.0/32 is subnetted, 1 subnets
O 33.33.33.33 [110/11112] via 192.168.13.3, 001:10, Tunnel0
D 192.168.23.0/24 [90/30720] via 192.168.12.2, 00:44:47, FastEthernet0/0
11.0.0.0/24 is subnetted, 1 subnets
C 11.11.11.0 is directly connected, Loopback1

If you see the OSPF update you can assume it's working correctly. A better idea is to use some show and debug commands to confirm that it's actually working.

Rene,

i can up the tunnel. My line protocol stays down. any reason?
I used the fe interface as source.

sorry, i can't bring up the tunnel.

***********Godzilla************
host Godzilla
line con 0
logg sy
int f0/0
ip add 192.168.12.1 255.255.255.0
no sh
!
int l0
ip add 1.1.1.1 255.255.255.0
!

router eigrp 1
netw 192.168.12.0 0.0.0.255
!
int tun 0
ip add 192.168.13.1 255.255.255.0
tu so f0/0
tu des 192.168.23.3
!
int l1
ip add 11.11.11.11 255.255.255.0
!
router ospf 1
!netw 192.168.12.0 0.0.0.255 are 0
netw 1.1.1.1 0.0.0.255 are 0
netw 11.11.11.11 0.0.0.255 are 0
netw 192.168.13.0 0.0.0.255 are 0
!

***********KingKong************

host KingKong
line con 0
logg sy
int f0/0
ip add 192.168.12.2 255.255.255.0
no sh
int f1/0
ip add 192.168.23.2 255.255.255.0
no sh
!
router eigrp 1
netw 192.168.12.0 0.0.0.255
netw 192.168.23.0 0.0.0.255
!

***********nessie********

host Nessie
line con 0
logg sy
int f0/0
ip add 192.168.23.3 255.255.255.0
no sh
!
int l0
ip add 3.3.3.3 255.255.255.0
!
router eigrp 1
netw 192.168.23.0 0.0.0.255
!
!
int tun 0
ip add 192.168.13.3 255.255.255.0
tu so f0/0
tu des 192.168.12.1
!
int l1
ip add 33.33.33.33 255.255.255.0
!
router ospf 1
!netw 192.168.23.0 0.0.0.255 are 0
netw 192.168.13.0 0.0.0.255 are 0
netw 3.3.3.3 0.0.0.255 are 0
netw 33.33.33.33 0.0.0.255 are 0
!

Great lab ..thanks and keep them coming!

Glad you like it!

Thanks for this Lab. Useful abd clear one for solid understanding.

Thanks Ersan

Hi,
1) We have configured loop back 0 (1.1.1.1 and 3.3.3.3)but never used it in GRE-config. Is this loop back not required for GRE?.
2) On tunnel interfaces, we assigned IPs 192.168.13.1 and 192.168.13.3 but we never used that too so we can assign any random IPs on tunnel interface. Then why we have given that IP?

On all the routers EIGRP is configured for basic connectivity. This way we can create a GRE tunnel between the two routers, otherwise they don't know how to reach each others IP address.

We use the IP addresses on the GRE tunnel so we can establish an OSPF adjacency between the two routers, the loopbacks are advertised in OSPF and learned through the GRE tunnel.

Is GNS3 still having problems loading configs from projects? Every time I load a project from a .net file downloaded from here the startup configs never load with the project, so what I am I doing wrong? Is there a special way to load the .net file with project open to get the configs at the same time?

Never mind I see that that there is no original configs, you start out with no configs in the routers and config from scratch in the lab, sorry for the confusion.

Most of my labs do have startup-configs, seems like i still have to fix this one...

Hi. If using IPIP encap instead of GRE in a prod environment(over an MPLS network), do you think it that the tunnel can handle the load if the remote connection is a stub area connection, and bandwidth statement added to the tunnel to raise its priority in OSPF?

I realize that GRE tunnels bw is 9k which makes it undesirable for sites with multiple links.

I love your labs man, you're easy to follow and accurate! You really have been helping my skill set ^-^

Rene,

I've been spending quite some time on your site & am really delighted to learn lot of stuff in a simple way. You're just amazing with your tech skills. Please do continue to post...

Building a single GRE tunnel, it worked. Let's say, i've 5 sites & i want to build a static tunnel between all these 5 sites...
Can you please tell me what will be the source & destination IP for each tunnel?
Would you be able to shed some light on this?

Cheers. Watched all 4 in this section and labbed them up. Many thanks. I need some more time in the day for all the vids.

great lab, thanks for posting it, it has all the information needed to start off doing tunneling