I think it has to do with GNS3 (whether the hardware it is running on or
just GNS3) -
I see the SHAM Links come up but it is not preferred over the backdoor link
even though the cost of the SHAM is 1 and the cost of the backdoors are
10000
Anthony/Marko/Tyson - Any comments
PE1
Sham Link OSPF_SL2 to address 33.33.33.33 is up
Area 14 source address 11.11.11.11
Run as demand circuit
DoNotAge LSA allowed. Cost of using 1 State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40,
Hello due in 00:00:00
PE2
Sham Link OSPF_SL2 to address 11.11.11.11 is up
Area 14 source address 33.33.33.33
Run as demand circuit
DoNotAge LSA allowed. Cost of using 1 State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40,
Hello due in 00:00:05
From: Jonathan Fernatt [mailto:[email protected]]
Sent: May-23-11 1:26 PM
To: Jason Maynard
Cc: [email protected]
Subject: Re: [OSL | CCIE_RS] OSPF SHAMLinks
I mis-read your configuration sorry :)
On Mon, May 23, 2011 at 1:25 PM, Jonathan Fernatt <[email protected]>
wrote:
It has been a while but I believe if you remove the commands redistributing
the sham link endpoints into OSPF you will be good to go.
Jon
On Mon, May 23, 2011 at 12:31 PM, Jason Maynard <[email protected]>
wrote:
I thought I would run this by the group as I am not getting the expected
results in GNS3. Is there anything that I am missing when creating
shamlinks?
1. Create a loopback with a /32 address on PE Routers
2. Add these loopbacks to the VRF
3. Advertise these loopbacks into the vrf address-family in BGP (Do
advertise these networks in OSPF)
4. Create a shamlink in the OSPF vrf process
5. Ensure /32 loopback addresses create above are not advertised in OSPF
Complete Configuration (I only included the relevant information and it is
assumed the you have an already functioning MPLS network)
PE1
Step 1 and 2
interface Loopback100
description SHAMLINK Interface
ip vrf forwarding CUSTA
ip address 11.11.11.11 255.255.255.255
Step 3
router bgp 100
address-family ipv4 vrf CUSTA
redistribute ospf 14 vrf CUSTA
network 11.11.11.11 mask 255.255.255.255
exit-address-family
Step 4
router ospf 14 vrf CUSTA
area 0 sham-link 11.11.11.11 33.33.33.33
redistribute bgp 100 subnets route-map SHAM
Step 5
access-list 10 permit 33.33.33.33
access-list 10 permit 11.11.11.11
!
route-map SHAM deny 10
match ip address 10
!
route-map SHAM permit 20
PE2
Step 1 and 2
interface Loopback100
description SHAMLINK Interface
ip vrf forwarding CUSTA
ip address 33.33.33.33 255.255.255.255
Step 3
router bgp 100
redistribute ospf 14 vrf CUSTA
network 33.33.33.33 mask 255.255.255.255
exit-address-family
Step 4
router ospf 14 vrf CUSTA
area 0 sham-link 33.33.33.33 11.11.11.11
redistribute bgp 100 subnets route-map SHAM
Step 5
access-list 10 permit 33.33.33.33
access-list 10 permit 11.11.11.11
!
route-map SHAM deny 10
match ip address 10
!
route-map SHAM permit 20
Blog: <http://packetsanalyzed.blogspot.com/>
http://packetsanalyzed.blogspot.com/
_______________________________________________
For more information regarding industry leading CCIE Lab training, please
visit www.ipexpert.com
Are you a CCNP or CCIE and looking for a job? Check out
www.PlatinumPlacement.com
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit
www.ipexpert.com
Are you a CCNP or CCIE and looking for a job? Check out
www.PlatinumPlacement.com
