DMVPN Lab 5 Implement VRF
Posted: Fri Dec 06, 2019 6:16 pm
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Image needed: Cisco IOSv
Description:
In this lab, you will modify DMVPN configurations to implement VRF in the topology, you need to understand the reason behind this project, VRF will partition the global routing table into multiple routing tables. The global routing table will still carry information for ISP connectivities, while VRF instance will have DMVPN routes in it, the reason for doing this is simple, currently, in global routing tables across all DMVPN routers, you have statically configured default routes pointing to ISP over which DMPVPN routers establish GRE multipoint tunnel connections, but what if LAN networks of the spokes need to access the internet, which is not going to be current ISP, connecting routers in DMVPN topology but HQ router using different ISP connection, in this case, spokes routers will use current static default routes pointing to current ISP and not to HQ router even though HQ router will advertise default route over OSPF, due to the higher AD of OSPF, spoke routers will choose statically configured default route, leading all traffic distant for the Internet to the current ISP where traffic will be dropped because ISP does not accept packets with private IP addresses. Your goal is to direct traffic from spokes LAN distant to the Internet through HQ router by using VRF and NAT. Lab details included within the .unl file.
Topology:
Image needed: Cisco IOSv
Description:
In this lab, you will modify DMVPN configurations to implement VRF in the topology, you need to understand the reason behind this project, VRF will partition the global routing table into multiple routing tables. The global routing table will still carry information for ISP connectivities, while VRF instance will have DMVPN routes in it, the reason for doing this is simple, currently, in global routing tables across all DMVPN routers, you have statically configured default routes pointing to ISP over which DMPVPN routers establish GRE multipoint tunnel connections, but what if LAN networks of the spokes need to access the internet, which is not going to be current ISP, connecting routers in DMVPN topology but HQ router using different ISP connection, in this case, spokes routers will use current static default routes pointing to current ISP and not to HQ router even though HQ router will advertise default route over OSPF, due to the higher AD of OSPF, spoke routers will choose statically configured default route, leading all traffic distant for the Internet to the current ISP where traffic will be dropped because ISP does not accept packets with private IP addresses. Your goal is to direct traffic from spokes LAN distant to the Internet through HQ router by using VRF and NAT. Lab details included within the .unl file.
Topology: