How does Nhrp work in DMVPN?

NHRP clients register themselves with the NHRP server and report their public IP address. The NHRP server keeps track of all public IP addresses in its cache. When one router wants to tunnel something to another router, it will request the NHRP server for the public IP address of the other router.

Why Eigrp is used in DMVPN?

The EIGRP Scale for DMVPN feature provides an increase in the scalability of the hub device to 2500 sessions. The increase in the number of sessions reduces the adverse impact on CPU, system buffers, interface buffers, and queues and it reduces resource contention on the hub during initial startup of a DMVPN network.

How do I check my DMVPN status?

Verify the basic connectivity

1. Ping from the hub to the spoke’s using NBMA addresses and reverse.
2. Also, use traceroute to check the path that the encrypted tunnel packets are taking.
3. Use the debug and show commands to verify no connectivity:

What are the steps to configure the DMVPN?

Four Steps to Fully Configure Cisco DMVPN

1. Configure the DMVPN Hub.
2. Configure the DMVPN Spoke(s)
3. Protect the mGRE tunnels with IPSecurity (optional)
4. Configure Routing Between DMVPN mGRE Tunnels (static routing or routing protocol)

How do I check my DMVPN tunnel status?

What are DMVPN phases?

A brief description of DMVPN phases: DMVPN phase 2 – Hub-to-spokes and spoke-to-spokes tunnels. One mGRE interface on the hub and one mGRE interface on each spoke. Routing protocols advertise routes with original next-hops (i.e. spokes may be next-hops, and hub doesn’t change next-hops to self).

What are the three phases of Dmvpn?

In its simplest form, DMVPN is a point-to-multipoint Layer 3 overlay VPN enabling logical hub and spoke topology supporting direct spoke-to-spoke communications depending on DMVPN design ( Phase 1, Phase 2 and Phase 3 ) selection.

What are the steps to configure the Dmvpn?

What should be considered for BGP over DMVPN?

Border Gateway Protocol (BGP) is also a viable solution for DMVPNs. It is well known for its proven capability to scale to a large number of peers/routes and with default timers, it puts less strain on the routers than other routing protocols. What needs to be considered for BGP over DMVPN? Should iBGP or eBGP be used?

How does EIGRP work with DMVPN Phase 2?

EIGRP works really well with DMVPN. There are a few things to be aware of, especially with phase 2. The most important concern is split horizon. This is EIGRP’s loop prevention mechanism. Split horizon prevents loops by never advertising a route out the interface that it was learned on.

Which is the best routing protocol for DMVPN?

BGP is going to be the final routing protocol we take a look at in this series. It’s a great solution for DMVPN, especially in large scale deployments. The biggest design choice we’ll have to make is whether to use eBGP or iBGP.

Can you use is-is on a DMVPN?

These are EIGRP, BGP, OSPF, and ODR. IS-IS is not an option for DMVPN, as DMVPN’s use IP for transport, while IS-IS does not. I’ve also not included RIP here, as well, it’s RIP, and if you’re serious about this, you’re probably not going to run RIP.