DMVPN issue

[ittechk4u1]

Hello Experts,

i am using this design from DMVPN.

1. Can i use two hub also both working as soke at the same time ?

2. I am using HUB as spoke because both are located on diff physical location.

so will it work or not ?

Thanks in advance

[ittechk4u1]

Who is that IP 172.25.156.52?- Its a Spoke

why you're not advertising it from Hub1? - What do you mean. 

when i do trace from one spoke to another ..its show two ways...

Spoke2#traceroute
Protocol [ip]:
Target IP address: 10.55.21.254
Source address: 10.52.21.254
Numeric display [n]:
Timeout in seconds [3]:
Probe count [3]:
Minimum Time to Live [1]:
Maximum Time to Live [30]:
Port Number [33434]:
Loose, Strict, Record, Timestamp, Verbose[none]:
Type escape sequence to abort.
Tracing the route to 10.55.21.254
VRF info: (vrf in name/id, vrf out name/id)
1 10.52.7.254 0 msec 0 msec 10 msec
2 10.52.6.254 0 msec 10 msec 0 msec
3 172.25.156.56 30 msec 30 msec 40 msec
4 172.25.56.55 60 msec 60 msec 70 msec
5 10.55.6.1 60 msec * 50 msec
6 10.55.7.1 60 msec * 50 msec
Spoke2#

----------------------------------------------------

check the route on one of the scope:  it shows the tunnel 156 , I feel its wrong it should be tunnel 56.

I think its becaus eof same dela yon tunnel 56 and tunnel 156!!!!!

SPOKE2#sh ip route | in 10.50.
D EX 10.50.0.0/16 [170/26368256] via 172.25.156.50, 19:20:21, Tunnel156
D 10.50.0.1/32 [90/26496000] via 172.25.156.50, 19:20:21, Tunnel156
D 10.50.0.2/32 [90/26496256] via 172.25.156.50, 19:20:21, Tunnel156
D 10.50.3.0/24 [90/26368256] via 172.25.156.50, 19:20:21, Tunnel156
D 10.50.4.0/24 [90/26368256] via 172.25.156.50, 19:20:21, Tunnel156
D 10.50.6.0/24 [90/26368256] via 172.25.156.50, 19:20:21, Tunnel156
SPOKE2#sh ip route | in 10.51.
D EX 10.51.0.0/16 [170/26626560] via 172.25.156.56, 12:19:49, Tunnel156
D 10.51.0.1/32 [90/26754560] via 172.25.156.56, 12:19:49, Tunnel156
D 10.51.0.2/32 [90/26752000] via 172.25.156.56, 12:19:49, Tunnel156
D 10.51.4.0/24 [90/26626560] via 172.25.156.56, 12:19:49, Tunnel156
D 10.51.6.0/24 [90/26626560] via 172.25.156.56, 12:19:49, Tunnel156
SPOKE2#sh ip route | in 10.55.
D EX 10.55.0.0/16 [170/26624256] via 172.25.156.56, 19:20:26, Tunnel156
D 10.55.0.1/32 [90/26752000] via 172.25.156.56, 19:20:26, Tunnel156
D 10.55.0.2/32 [90/26752256] via 172.25.156.56, 19:20:26, Tunnel156
D 10.55.3.0/24 [90/26624256] via 172.25.156.56, 19:20:26, Tunnel156
D 10.55.4.0/24 [90/26624256] via 172.25.156.56, 19:20:26, Tunnel156
D 10.55.6.0/24 [90/26624256] via 172.25.156.56, 19:20:26, Tunnel156
SPOKE2#sh ip route | in 10.56.
D EX 10.56.0.0/16 [170/26370560] via 172.25.156.56, 19:20:29, Tunnel156
D 10.56.0.1/32 [90/26496000] via 172.25.156.56, 19:20:29, Tunnel156
D 10.56.0.2/32 [90/26498560] via 172.25.156.56, 19:20:29, Tunnel156
D 10.56.3.0/24 [90/26370560] via 172.25.156.56, 00:08:00, Tunnel156
D 10.56.4.0/24 [90/26370560] via 172.25.156.56, 19:20:29, Tunnel156
D 10.56.6.0/24 [90/26370560] via 172.25.156.56, 19:20:29, Tunnel156

--------------------------------------------------

Here is the output of SH dmvpn and sh ip eig ne form both hubs:

HUB1#sh ip ei ne
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
4 172.25.56.51 Tu56 10 07:39:30 51 1584 0 112004
10 172.25.56.58 Tu56 12 15:09:55 28 1584 0 174041
5 172.25.56.52 Tu56 12 15:09:55 30 1584 0 181706
3 172.25.56.50 Tu56 12 15:10:00 39 1584 0 194257
2 172.25.56.55 Tu56 12 15:10:00 28 1584 0 150171
6 172.25.156.51 Tu156 13 15:21:54 30 1446 0 112002
11 172.25.156.50 Tu156 14 15:25:54 28 1446 0 194259
7 172.25.156.55 Tu156 11 20:58:37 17 1446 0 150170
9 172.25.156.58 Tu156 11 1d16h 41 1446 0 174039
8 172.25.156.52 Tu156 10 1d16h 30 1446 0 181704
HUB1#

----------------------------------------------------------------------------------------
HUB2#sh ip ei ne
EIGRP-IPv4 Neighbors for AS(1)
H Address Interface Hold Uptime SRTT RTO Q Seq
(sec) (ms) Cnt Num
11 172.25.156.58 Tu156 14 14:39:57 15 1242 0 174039
10 172.25.156.52 Tu156 13 14:39:57 41 1242 0 181704
9 172.25.56.58 Tu56 10 14:39:58 18 1434 0 174041
8 172.25.56.52 Tu56 10 14:40:03 48 1434 0 181706
7 172.25.156.55 Tu156 14 14:40:12 47 1242 0 150170
6 172.25.56.55 Tu56 10 14:40:17 55 1434 0 150171
0 172.25.56.56 Tu56 14 15:09:48 44 1434 0 9001
5 172.25.156.51 Tu156 12 15:22:12 118 1242 0 112002
4 172.25.56.51 Tu56 13 15:22:15 131 1434 0 112004
1 172.25.156.56 Tu156 13 15:25:47 104 1242 0 9003
---------------------------------------------------------------------------------------

----------------

HUB1:

172.25.56.56

172.25.156.56

HUB2:

172.25.56.50

172.25.156.50

Spoke1: 

172.25.56.51

172.25.156.51

Spoke2:

172.25.56.52

172.25.156.52

Spoke3:

172.25.56.55

172.25.156.55

Spoke4:

172.25.56.58

172.25.156.58

Thanks

[Francesco Molino]

Hi

What I meant is:
- you're trying to reach a device on the subnet 10.50.0.0/16
- This subnet is advertised only by Hub2 and that's why your routing shows tunnel156 as next hop.
- you said that this subnet is also available on Hub1 but not advertising it. If you want your traffic to pass-through Hub1, this subnet as to be announced from Hub1 as well and it will be preferred unless there is something else I don't know in your architecture that will make Hub2 preferred next-hop for that subnet

[ittechk4u1]

see my EIGRP config on HUBs and spokes:

Hub1:

router eigrp 1
network 10.56.0.0 0.0.255.255
network 172.25.156.0 0.0.0.255
network 172.25.56.0 0.0.0.255
passive-interface Loopback0
no auto-summary

spoke1:

router eigrp 1
network 10.51.0.0 0.0.255.255
network 172.25.156.0 0.0.0.255
network 172.25.56.0 0.0.0.255
passive-interface Loopback0
no auto-summary

is it ok ? or you want that i should add the other spokes and hub network IP in each spoke and hub?

Thanks

[Francesco Molino]

Ok but on Hub2 you're advertising network 10.50.0.0/16 right?

Is this subnet also accessible from Hub1 ? Can you advertise it from Hub1 as well?

[ittechk4u1]

Yes each HUB and spoke is reachable from each spoke/hub. Why you want me to advertise 10.50.0.0/16 on  HUB1 when it’s already reachable!!!

[Francesco Molino]

Ok Maybe I miss-spelled my explanation. Let's try again.

On the spoke router, when doing a show ip route 10.50.0.0, it knows it with Hub2 as next-hop and that's normal because Hub2 is advertising that network.

Can you do the command "sh ip route 10.50.0.0" on spoke, hub1 and hub2 router please?

[ittechk4u1]

Again: every spke and hub can reach to each each other.

here is the output whihc u asked:

SPOKE2#sh ip route 10.50.0.0
Routing entry for 10.50.0.0/16
Known via "eigrp 1", distance 170, metric 26368256, type external
Redistributing via eigrp 1, nhrp
Last update from 172.25.156.50 on Tunnel156, 1d00h ago
Routing Descriptor Blocks:
172.25.156.50, from 172.25.156.50, 1d00h ago, via Tunnel156
Route metric is 26368256, traffic share count is 1
Total delay is 30010 microseconds, minimum bandwidth is 100 Kbit
Reliability 255/255, minimum MTU 1300 bytes
Loading 5/255, Hops 1
* 172.25.56.50, from 172.25.56.50, 1d00h ago, via Tunnel56
Route metric is 26368256, traffic share count is 1
Total delay is 30010 microseconds, minimum bandwidth is 100 Kbit
Reliability 255/255, minimum MTU 1300 bytes
Loading 5/255, Hops 1
SPOKE2#
----------------------------------------------------------------------------
HUB2(10.50.0.0 - itself)

HUB2sh ip route 10.50.0.0
Routing entry for 10.50.0.0/16
Known via "static", distance 1, metric 0
Redistributing via eigrp 1, nhrp
Advertised by eigrp 1 route-map static2EIGRP
Routing Descriptor Blocks:
* 10.50.6.1
Route metric is 0, traffic share count is 1
HUB2#
---------------------------------------------------------------------------

HUB1#sh ip route 10.50.0.0
Routing entry for 10.50.0.0/16
Known via "eigrp 1", distance 170, metric 25856256, type external
Redistributing via nhrp, eigrp 1
Last update from 172.25.56.50 on Tunnel56, 1d00h ago
Routing Descriptor Blocks:
* 172.25.56.50, from 172.25.56.50, 1d00h ago, via Tunnel56
Route metric is 25856256, traffic share count is 1
Total delay is 10010 microseconds, minimum bandwidth is 100 Kbit
Reliability 255/255, minimum MTU 1300 bytes
Loading 12/255, Hops 1
HUB1#

Thanks

[Francesco Molino]

IP 172.25.56.50 is your Hub2 router.
Hub1 knows it as external route from Hub2, that's why spoke routers will prefer going directly to Hub2 instead of passing-through Hub1.
Is this subnet spanned over DC where Hub2 and Hub1 are?

Can you run on spoke the following command: show ip eigrp topology all-links
and paste it a text file please?

[ittechk4u1]

Is this subnet spanned over DC where Hub2 and Hub1 are? 

Yes on DC routers we have spanned the completed 10.0.0.0/8 Network.

Please find the output of the command in text file.

I changed the delay on tunnel 56 (delay 3000) , on tunnel 156 (delay 3001) and it looks working normally.

Thanks

[Francesco Molino]

It looks like good.

As I said, if the network is spanned accross the DC, not the /8 but the more specific /24, you can advertise it from both DCs or as you did, just play with delay to prefer 1 route versus the other.