05-31-2013 12:30 PM - edited 03-04-2019 08:04 PM
Hi,
I have got a remote office which is a few hops away with subnet 192.168.25.0/24 using LES links. Our other service provider connects some of our other remote sites via MPLS cloud to our core. One of these connected sites is a 192.168.44.0/24 subnet. I need our subnet 25.0/24 to be available at 44.0/24 hence am required to create a VLAN 25 on our core Cat 4506 switches but once i create a VLAN 25 then routing points the 25.0/24 subnet to be directly connected instead to going out the right path. Currently using EIGRP across the infrastructure. Please see below some details of routes before and after.
BEFORE when the VLAN 25 is disabled:
CSW#sh ip route 192.168.25.1
Routing entry for 192.168.25.0/24
Known via "eigrp 200", distance 90, metric 3328, type internal
Redistributing via eigrp 200
Last update from 172.19.102.2 on Vlan102, 00:00:07 ago
Routing Descriptor Blocks:
* 172.19.102.2, from 172.19.102.2, 00:00:07 ago, via Vlan102
Route metric is 3328, traffic share count is 1
Total delay is 30 microseconds, minimum bandwidth is 1000000 Kbit
Reliability 255/255, minimum MTU 1500 bytes
Loading 6/255, Hops 2
AFTER when the VLAN 25 is enabled:
CSW#conf t
Enter configuration commands, one per line. End with CNTL/Z.
CSW(config)#int vlan 25
CSW(config-if)#no shut
CSW(config-if)#exit
CSW(config)#exit
CSW1#sh ip route 192.168.25.1
Routing entry for 192.168.25.0/24
Known via "connected", distance 0, metric 0 (connected, via interface)
Redistributing via eigrp 200
Routing Descriptor Blocks:
* directly connected, via Vlan25
Route metric is 0, traffic share count is 1
Kindly advise.
Many thanks in advance.
Solved! Go to Solution.
05-31-2013 03:09 PM
There are quite a few things about your environment that we do not know and they would help us to figure out what suggestions to make. So some clarification of your network topology would be helpful.
But if I am understanding correctly you have a network 192.168.25.0/24 at a remote site. Then you created a vlan on your core switch and assigned network 192.168.25.0/24 on the core switch. The result is that now you have network 192.168.25.0 appearing in two separate places in your network. That is a serious problem and the result is that your core thinks that it is a local connection and will no longer forward to the remote site.
My suggestion is to remove vlan 25 from your core and then to figure out a different routing solution that would make network 192.168.25.0 be advertised to the 44.0 site.
HTH
Rick
06-01-2013 06:36 AM
I agree with Rick. I seriously do not recommend creating your 192.168.25.0 network on your core (it already exists in your network!), it can cause major problems if were not careful. Am I missing something here?
You have the 25.0 network on a dedicated LES circuit on some other site, connected in your environment, and you want to advertise this network in to the MPLS cloud - office(s)/site(s) connected. So it will be reachable.
Shouldn't it be simple enough to advertise the 25.0 network into the 'MPLS Cloud' (MPLS VPN - I assume) Then your remote sites in this environment would be able to reach 25.0 network and vice versa (if routing is fully converged and routes are propagated).
Is there a routing protocol being used between you and the provider to learn routes both for your core's and remote sites?
Advertisement path:
This is all assuming that you are using a dynamic routing protocol between yourself and your MPLS provider and that I have understood the scenario. Please confirm and provide more details.
Hope this helps
Please rate useful posts & remember to mark any solved questions as answered. Thank you.
05-31-2013 03:09 PM
There are quite a few things about your environment that we do not know and they would help us to figure out what suggestions to make. So some clarification of your network topology would be helpful.
But if I am understanding correctly you have a network 192.168.25.0/24 at a remote site. Then you created a vlan on your core switch and assigned network 192.168.25.0/24 on the core switch. The result is that now you have network 192.168.25.0 appearing in two separate places in your network. That is a serious problem and the result is that your core thinks that it is a local connection and will no longer forward to the remote site.
My suggestion is to remove vlan 25 from your core and then to figure out a different routing solution that would make network 192.168.25.0 be advertised to the 44.0 site.
HTH
Rick
06-01-2013 06:36 AM
I agree with Rick. I seriously do not recommend creating your 192.168.25.0 network on your core (it already exists in your network!), it can cause major problems if were not careful. Am I missing something here?
You have the 25.0 network on a dedicated LES circuit on some other site, connected in your environment, and you want to advertise this network in to the MPLS cloud - office(s)/site(s) connected. So it will be reachable.
Shouldn't it be simple enough to advertise the 25.0 network into the 'MPLS Cloud' (MPLS VPN - I assume) Then your remote sites in this environment would be able to reach 25.0 network and vice versa (if routing is fully converged and routes are propagated).
Is there a routing protocol being used between you and the provider to learn routes both for your core's and remote sites?
Advertisement path:
This is all assuming that you are using a dynamic routing protocol between yourself and your MPLS provider and that I have understood the scenario. Please confirm and provide more details.
Hope this helps
Please rate useful posts & remember to mark any solved questions as answered. Thank you.
06-01-2013 06:55 AM
Hi Bilal,
Many thanks for your response.
I will contact our MPLS service provider and discuss this further. Our MPLS service provider is using, i believe subinterfaces on ASR 1002 router and wants us to create a VLAN 25 so that the interface status comes up. I haven't got much details about the configs of their box but will let you know how it goes.
Thank you once again.
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