I'm trying to set up a DMVPN Phase 2 configuration, but I cannot manage to get past Phase 1 because the hub router's tunnel interface refuses to disable split-horizon. The spokes never form an EIGRP adjacency to teach other and never learn routes directly to the other spokes.
I'm looking for suggestions on something I may be doing wrong. I've tried disabling on the interface itself and in the routing configuration as well just be sure. When I check the interface, it still says split horizon is enabled.
I haven't added any optimizations commands yet or anything unnecessary to establish communication. Once I can get my spokes talking directly, I'll worry about improving the configuration. This is solely a test environment right now.
EDIT: To clarify, the fact that spokes receive no routes to other spokes and never form adjacencies tells me that split horizon is still on. The Tun1601 interface shows split horizon still enabled. Sh ip eigrp interface says thats its disabled. Short of taking a packet capture and investigating what's really happen, it seems it is in fact not disabled.
Hub:
interface Tunnel1601 description DMVPN over INTERNET bandwidth 1000 ip vrf forwarding Green ip address 172.17.13.7 255.255.252.0 no ip redirects ip mtu 1400 no ip split-horizon eigrp 1601 ip nhrp authentication NHRPKey2 ip nhrp map multicast dynamic ip nhrp network-id 1601 ip nhrp holdtime 300 ip nhrp registration timeout 30 tunnel source Port-channel2.7 tunnel mode gre multipoint tunnel key 100001 tunnel vrf INTERNET tunnel protection ipsec profile IPSEC-INTERNET router eigrp DMVPN-INTERNET ! address-family ipv4 unicast vrf Green autonomous-system 1601 ! af-interface Tunnel1601 no next-hop-self no-ecmp-mode no split-horizon exit-af-interface ! topology base exit-af-topology network 172.17.12.0 0.0.3.255 network 172.30.3.0 0.0.0.255 network 172.30.6.0 0.0.0.255 exit-address-family
Sh ip int tun1601:
Tunnel1601 is up, line protocol is up
Internet address is 172.17.13.7/22
Broadcast address is 255.255.255.255
Address determined by setup command
MTU is 1400 bytes
Helper address is not set
Directed broadcast forwarding is disabled
Multicast reserved groups joined: 224.0.0.10 224.0.0.251
Outgoing access list is not set
Inbound access list is not set
Proxy ARP is enabled
Local Proxy ARP is disabled
Security level is default
Split horizon is enabled
ICMP redirects are never sent
ICMP unreachables are always sent
ICMP mask replies are never sent
IP fast switching is enabled
IP Flow switching is disabled
IP CEF switching is enabled
IP CEF switching turbo vector
IP Null turbo vector
VPN Routing/Forwarding "Green"
Associated unicast routing topologies:
Topology "base", operation state is UP
Tunnel VPN Routing/Forwarding "INTERNET"
IP multicast fast switching is enabled
IP multicast distributed fast switching is disabled
IP route-cache flags are Fast, CEF
Router Discovery is disabled
IP output packet accounting is disabled
IP access violation accounting is disabled
TCP/IP header compression is disabled
RTP/IP header compression is disabled
Probe proxy name replies are disabled
Policy routing is disabled
Network address translation is disabled
BGP Policy Mapping is disabled
Input features: MCI Check, TCP Adjust MSS
Output features: TCP Adjust MSS
Post encapsulation features: IPSEC Post-encap output classification
IPv4 WCCP Redirect outbound is disabled
IPv4 WCCP Redirect inbound is disabled
IPv4 WCCP Redirect exclude is disabled
@cpt_fink
sh ip eigrp vrf Green int
EIGRP-IPv4 VR(DMVPN-INTERNET) Address-Family Interfaces for AS(1601)
VRF(Green)
Xmit Queue PeerQ Mean Pacing Time Multicast Pending
Interface Peers Un/Reliable Un/Reliable SRTT Un/Reliable Flow Timer Routes
Tu1601 1 0/0 0/0 62 0/22 252 0
Lo2 0 0/0 0/0 0 0/0 0 0
Gi0/1 0 0/0 0/0 0 0/0 0 0
Best Answer
Try adding this command to your tunnel interface. Your spokes are receiving routes with the next-hop as the hub router without it.