Hi,
Can we expect DMVPN IPv6 Transport on v5 exam?
I tried to lab this up but I can't get this working. I don't quite undestand how NHRP deals with IPv6 link-local addresses.
I have very simple topology, where R1 is the hub and R2 is the spoke.
NBMA network is IPv6 only.
R1#sh run int gi1.201
Building configuration...
Current configuration : 134 bytes
!
interface GigabitEthernet1.201
encapsulation dot1Q 201
ipv6 address 2001:169:1:201::1/64
description INTERNET
end
R1#sh run int tun0
Building configuration...
Current configuration : 220 bytes
!
interface Tunnel0
no ip address
ipv6 address DEAD:BEEF::1/64
ipv6 nhrp map multicast dynamic
ipv6 nhrp network-id 1
tunnel source 2001:169:1:201::1
tunnel mode gre multipoint ipv6
tunnel path-mtu-discovery
end
R2#sh run int gi1.202
Building configuration...
Current configuration : 136 bytes
!
interface GigabitEthernet1.202
encapsulation dot1Q 202
ip address 169.1.202.2 255.255.255.0
ipv6 address 2001:169:1:202::2/64
description INTERNET
end
R2#sh run int tun0
Building configuration...
Current configuration : 310 bytes
!
interface Tunnel0
no ip address
ipv6 address DEAD:BEEF::2/64
ipv6 nhrp network-id 1
ipv6 nhrp nhs DEAD:BEEF::1 nbma 2001:169:1:201::1 multicast
tunnel source 2001:169:1:202::2
tunnel mode gre multipoint ipv6
tunnel path-mtu-discovery
end
Now, when I run EIGRP on top of DMVPN it will establish adjacency, but it cannot exchange topology information.
The adjacency is torn down after 16 retransmissions. It seems that the packets destined to far-end link-local address can't go through.
On the hub, NHRP cache looks as below:
R1#sh ipv6 nhrp
DEAD:BEEF::2/128 via DEAD:BEEF::2
Tunnel0 created 00:07:28, expire 01:52:31
Type: dynamic, Flags: unique registered used nhop
NBMA address: 2001:169:1:202::2
FE80::21E:BDFF:FE89:5000/128 via DEAD:BEEF::2
Tunnel0 created 00:09:04, expire 01:52:31
Type: dynamic, Flags: unique registered
NBMA address: 2001:169:1:202::2
On the spoke:
R2#sh ipv6 nhrp
DEAD:BEEF::1/128 via DEAD:BEEF::1
Tunnel0 created 00:00:34, never expire
Type: static, Flags: used
NBMA address: 2001:169:1:201::1
FE80::21E:49FF:FE33:E400/128 via FE80::21E:49FF:FE33:E400
Tunnel0 created 00:00:33, never expire
Type: static, Flags: nhs-ll
NBMA address: 2001:169::
R2#
Why the link-local address mapping on the spoke is static and what does the flag "nhs-ll" mean? Also the NBMA address is strange, shouldn't it be 2001:169:1:201::1?