09-25-2019 10:52 PM
Hello,
I have two sites are connected together through fiber, OSPF is configured on both core switches, now the problem is; I have VLAN needs to configured on both sites
Site A: VLAN 10, SVI 10.10.10.1
Site B: VLAN 10, SVI 10.10.10.2
I can reach only one site although the VLAN has been allowed in the trunk between both sites.
Problem description;
From site A I can reach servers in site A (ex. 10.10.10.3) and from Site B i can reach (ex. 10.10.10.4) but from Site A i'm not able to reach 10.10.10.4 in site B, and even the SVI on site B is not reachable from Site A, now when i shutdown the SVI on Site A, Site B became reachable from Site A due to passing through OSPF as a L3 but site A became unreachable from Site B.
Any advice please?
09-25-2019 11:21 PM
Hi,
It looks like you are using the same network on both sites; that is the reason for connectivity failure between the two sites. If you share your configuration, we can provide more advise.
HTH,
Meheretab
09-26-2019 12:07 AM
I won't be able to share as is configuration but it looks like below;
Core Switch site A:
VLAN 20
connected to site B
ip address 20.20.20.1 255.255.255.252
VLAN 10
ip address 10.10.10.1 255.255.255.0
interface po 1
trunk to Site B
switch port mode trunk
switch port trunk allowed vlan 10 20
ospf 1
redistribute connected
redistribute static
network 20.20.20.0 0.0.0.3 area 0.0.0.0
Core Switch site B:
VLAN 20
connected to site A
ip address 20.20.20.2 255.255.255.252
VLAN 10
ip address 10.10.10.2 255.255.255.0
interface po 1
trunk to Site A
switch port mode trunk
switch port trunk allowed vlan 10 20
ospf 1
redistribute connected
redistribute static
network 20.20.20.0 0.0.0.3 area 0.0.0.0
09-26-2019 03:09 AM
Hi,
Are you using VPN between both sites? What type of connectivity is there?
There are multiple options as:
VXLAN, VLAN Mapping, NATing (One to One translate) etc. But I hope, NATing would resolve your issue.
09-26-2019 05:50 AM
09-26-2019 12:27 PM
is this straight link? if yes - can you see cdp neighbor?
sw 1 <----fiber-----> sw 2
09-26-2019 10:25 PM
09-26-2019 07:13 AM
Looks like you have port channel configured. Can you please check the status of this portchannel and the interfaces binded to it.
Quick question : is there any connectivity for other vlans between sites through this inter-link? Except vlan 10.
09-26-2019 10:24 PM
09-25-2019 11:27 PM
Can I know why you want to run OSPF when all devices are in same subnet?
09-26-2019 12:04 AM
It is possible that initially these were two different isolated sites with the same subnet (10.10.10.х/24), and the task of merging appeared later.
09-26-2019 12:10 AM
Actually there are a lot of other networks that needs to be redistributed using OSPF
09-26-2019 12:18 AM
if you want to redistribute static networks you need to use
redistribute connected subnets
09-26-2019 01:04 AM
They are already redistributed i have no issues with OSPF
09-26-2019 02:41 AM
Hi,
i assume that you have directly connected backbone (fiber) between 2 networks. if i understood correctly.
in this case, if you are using same VLAN and network ranges at both sites, you dont need to configure routing protocol to do routing. because both core switches are connected with L2 link. you can configure backbone as a trunk and allow VLANs you already have. also, in this case you have to use 1 switch as a L3 switch with SVIs for different VLAN gateways on inter vlan routing purpose. please correct me if i am understood in wrong way.
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