03-08-2009 08:27 PM - edited 03-04-2019 03:51 AM
Hi I am trying to setup vrf's but I need to get my network to function properly first, so I have 4 routers and I am running bgp between R2&R3, OSPF between R1&R2 and R3&R4. Router R3 and R4 can ping all the routers on my network but R4 and R1 can only ping their directly connected routers. I have redistributed OSPF into BGP and vice versa on R4&R3 as below.
R1--R2--R3--R4
R2
router ospf 1
log-adjacency-changes
redistribute bgp 100 metric 2 subnets
network 4.4.4.4 0.0.0.0 area 0
network 165.148.122.0 0.0.0.255 area 0
!
router bgp 100
no synchronization
bgp log-neighbor-changes
network 4.4.4.4 mask 255.255.255.255
network 165.148.120.0 mask 255.255.255.252
redistribute ospf 1 metric 2
neighbor 165.148.120.1 remote-as 100
no auto-summary
!
R3
router ospf 1
log-adjacency-changes
redistribute bgp 100 metric 2 subnets
network 1.1.1.1 0.0.0.0 area 0
network 165.148.121.0 0.0.0.3 area 0
!
router bgp 100
no synchronization
bgp log-neighbor-changes
network 1.1.1.1 mask 255.255.255.255
network 165.148.120.0 mask 255.255.255.252
redistribute ospf 1 metric 2
neighbor 165.148.120.2 remote-as 100
no auto-summary
!
What must I do for router 1&4 to be able to ping all other routers. Is it good practice for me to advertise all other networks in OSPF for router R2&R3?
03-09-2009 12:56 AM
Could you please post the output of < sh ip bgp and sh ip route from R2 and R3
Narayan
03-09-2009 12:58 AM
Hello Lawrence,
to correctly deploy an MPLS network you should use a common IGP (OSPF in your case) on all the backbone routers.
then you can build a full mesh of iBGP sessions using loopbacks that are advertised in OSPF.
I would use for this the same loopbacks that are used by LDP to exchange messages.
the iBGP sessions then need to be of MP-BGP
router bgp 100
no bgp default ipv4-unicast
address-family ipv4 unicast
neigh x.x.x.x activate
address-family vpnv4
neigh x.x.x.x activate
neigh x.x.x.x send-community extended
Edit:
if you want to setup an inter-as scenario you need to put two routers in AS 100 and two routers in AS 200 but for each subset of routers you should follow the guidelines described above
Hope to help
Giuseppe
03-11-2009 01:41 PM
R2
sh ip route
1.0.0.0/32 is subnetted, 1 subnets
O 1.1.1.1 [110/2] via 165.148.120.1, 00:58:28, ATM3/0.100
155.239.0.0/24 is subnetted, 1 subnets
C 155.239.247.0 is directly connected, FastEthernet0/2
155.1.0.0/24 is subnetted, 1 subnets
C 155.1.1.0 is directly connected, GigabitEthernet0/3
4.0.0.0/32 is subnetted, 1 subnets
C 4.4.4.4 is directly connected, Loopback0
C 192.11.1.0/24 is directly connected, GigabitEthernet0/1
165.148.0.0/30 is subnetted, 1 subnets
C 165.148.120.0 is directly connected, ATM3/0.100
R3
sh ip route
1.0.0.0/32 is subnetted, 1 subnets
C 1.1.1.1 is directly connected, Loopback0
155.239.0.0/24 is subnetted, 1 subnets
C 155.239.247.0 is directly connected, GigabitEthernet0/3
155.1.0.0/24 is subnetted, 1 subnets
C 155.1.1.0 is directly connected, GigabitEthernet0/2
3.0.0.0/32 is subnetted, 1 subnets
B 3.3.3.3 [20/0] via 165.148.121.2, 00:17:01
4.0.0.0/32 is subnetted, 1 subnets
O 4.4.4.4 [110/2] via 165.148.120.2, 01:01:53, ATM1/0.100
C 192.5.1.0/24 is directly connected, GigabitEthernet0/1
165.148.0.0/30 is subnetted, 2 subnets
C 165.148.121.0 is directly connected, Serial6/0
C 165.148.120.0 is directly connected, ATM1/0.100
the problem here is once I apply the ip vrf for command on th interface on the PE's, the CE's drops immediately..
03-09-2009 02:52 AM
Hi
Just an FYI, you cannot redistribute BGP into any IGP without the BGP command :-
bgp redistribute-internal
You will need to add this to your config on router 2 under router bgp 100, or if you go with the above example, it will go under address-family ipv4.
03-09-2009 08:18 AM
I tried all of the above configs but i still can't get it right.
please confirm this for me, to run mpls do I need to have a P router, and PE's. I've configured only these two commands mpls ip, mpls label protocol ldp between the two routers (R2&R3) to create an mpls cloud so that i can configure my vrf's on the PE and CE.
Do I need to to have mpls configurations on the P router before I can generate traffic from one end to another making use of vrf?
03-09-2009 08:48 AM
Lawrence,
It should be fine to have "mpls ip" configured only between r2 and r3 if those are your PEs. You do not necessarily need P routers to get MPLS VPN working. Directly connected PEs will do just fine.
Regards
03-09-2009 10:26 AM
03-09-2009 06:59 PM
I will be trying the configs you gave me in three hours, I will provide feedback. I can't access my lab at this stage I don't know what happened. will be checking in the morning(in 4 hours from now).
03-10-2009 05:40 AM
I have tried your configs, my problem now is: I cannot activate the neighbor on address-family vpnv4 here is an error message "Specify remote-as or peer-group commands first".
another question is "is it a must to have three routers(PE)?
Can it work with my sketch(only four routers.
03-10-2009 05:45 AM
Yes it can... you can remove the RR in my design
"Cannot configure the local system as neighbor".
This means that you are trying to use using the routers own ip address instead of the peer neighbor command.. just chnage this to the other peer
Narayan
03-10-2009 05:46 AM
Lawrence,
As the message indicates, you are trying to activate using the address of the local end when you should be using the remote end as defined in global bgp mode.
As to your other question, you can run mpls vpn with only two PEs, no P router.
Regards
03-10-2009 06:13 AM
sorry my bad, you guys are correct but it's still giving me an errors message "Specify remote-as or peer-group commands first" when I try to activate the neighbor.
I am starting to suspect the ios. this router is using version 12.2(31)SB9, the other router is using version 12.4(21) and this one does accept this configs. i once tried to upgrade to the recent version but it's failing to boot from the latest..
03-10-2009 06:29 AM
I forgot to put it the remote-as.. thanks for your help but I am still proceeding with my configs not done yet.
03-10-2009 06:47 AM
Hello Lawrence,
on older IOS version you need to give
router bgp 100
no bgp default ipv4-unicast
this is to be able then to use the address-families
Hope to help
Giuseppe
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