Migrating from Nortel 5500 to VSP 7200

[Desiboy2019]

Hello Everyone. We are migrating our core switches from Nortel 5500 to VSP 7200 Series. For nortel switches we've used OSPF. For VSP's we wanted to use Fabric . we've configured 2 VSP's with MLT between them with IS-IS. we've connected the new cores to old cores by a trunk port with a Management VLAN. From the new switch i am able to ping to other side of the old cores and all the IPs. So i've created a new VLAN in new cores. by using the access port with the new VLAN, i am not able to ping to the other side of the old core. I can only ping the new cores ?? Could you please someone help me out. Thank you in advance.

[Desiboy2019]

Firstly Thank you for your response Roger. I have default route enabled on the VSP7200 Switch , the route pointed to the old core(Nortel 5530). I am able to ping from the switch. But i could n't ping from new vlan in new core switch. I think its routing issue between the VLANs. I don't know how to route between the IS IS and ospf on the other side ??

Thank you.

[Roger_Lapuh]

It looks like you don't have routing enabled between the ERS5500 and the VSP7200. You either would have to turn on OSPF or add static routes to get your routing tables setup properly.
For a VLAN/IP subnet that is connected on old and new core, you would not need routing, but for subnets that are "behind" the routers, you need to ensure your routing tables are correct and both sides can see each other.

Roger