As with my last question, I am learning for my CCNA exam and currently I am bashing my head against the wall, while trying to solve "7.2.2.4 Troubleshooting GRE"
I'll explain the topology in a second. First let me document, which steps I have taken so far:
- RA's Ip addresses on t0 and G0/0 were switched. I corrected them
- RA's tunnel 0 interface had the wrong source and destination addresses. I set them to s:172.31.0.1 d: 192.168.1.1
Now, on RB theres this message:
%LINEPROTO-5-UPDOWN: Line protocol on Interface Tunnel0, changed state to up
%ADJ-5-PARENT: Midchain parent maintenance for IP midchain out of 0 65E900C0 - looped chain attempting to stack
%TUN-5-RECURDOWN: 0 temporarily disabled due to recursive routing
Topology:
Every IP address/network address as shown on the image is correct.
This is show interface tunnel 0
on RA:
Tunnel0 is up, line protocol is up (connected)
Hardware is Tunnel
Internet address is 192.168.1.1/30
MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 172.31.0.1 (GigabitEthernet0/0), destination 192.168.1.2
Tunnel protocol/transport GRE/IP
Show interface tunnel 0
on RB:
Tunnel0 is up, line protocol is up (connected)
Hardware is Tunnel
Internet address is 192.168.1.1/30
MTU 17916 bytes, BW 100 Kbit/sec, DLY 50000 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation TUNNEL, loopback not set
Keepalive not set
Tunnel source 172.31.0.1 (GigabitEthernet0/0), destination 192.168.1.2
Tunnel protocol/transport GRE/IP
Key disabled, sequencing disabled
Checksumming of packets disabled
Show ip route
on RA:
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.31.0.0/24 is directly connected, GigabitEthernet0/0
L 172.31.0.1/32 is directly connected, GigabitEthernet0/0
192.168.1.0/24 is variably subnetted, 2 subnets, 2 masks
C 192.168.1.0/30 is directly connected, Tunnel0
L 192.168.1.1/32 is directly connected, Tunnel0
209.165.122.0/24 is variably subnetted, 2 subnets, 2 masks
C 209.165.122.0/30 is directly connected, Serial0/0/0
L 209.165.122.2/32 is directly connected, Serial0/0/0
S* 0.0.0.0/0 is directly connected, Serial0/0/0
Show ip route
on RB:
Gateway of last resort is 0.0.0.0 to network 0.0.0.0
64.0.0.0/8 is variably subnetted, 2 subnets, 2 masks
C 64.103.211.0/30 is directly connected, Serial0/0/0
L 64.103.211.2/32 is directly connected, Serial0/0/0
172.31.0.0/16 is variably subnetted, 2 subnets, 2 masks
C 172.31.1.0/24 is directly connected, GigabitEthernet0/0
L 172.31.1.1/32 is directly connected, GigabitEthernet0/0
192.168.1.0/32 is subnetted, 1 subnets
L 192.168.1.2/32 is directly connected, Tunnel0
S* 0.0.0.0/0 is directly connected, Serial0/0/0
Please help me understand this error by explaining what I am missing here and how to resolve this.
Kind regards.
**//EDIT: ** The task which needs to be fullfilled is that traffic from the 172.31.x.x networks on both sides needs to be tunneled.
//EDIT2: As it turns out Iw as talking Bullsh**. Here are the steps taken so far:
- RA's Ip addresses on t0 and G0/0 were switched. I corrected them
RA's tunnel 0 interface had the wrong source and destination addresses. I set them to s:172.31.0.1 d: 192.168.1.1
Changed Source address of tunnel 0 on RA to
172.31.0.1
- Changed Destination address of tunnel 0 on RB to
209.165.122.2
copy run start
on RB and thenreload
- Tunnel 0 on RB is now up and connected.
//EDIT3:
I finally worked it out. I went back in my curriculum to an earlier task, which did guide me through the whole configuration task.
The source on both routers for the tunnel is the S0/0/0
interface and the destination is the other routers S0/0/0
interface IP address.
This is highly counter intuitive, since in my head I was under the impression, the source is the traffic form the local LANs (the 172 interfaces), since the traffic from there needs to be tunneled.
Just for good measure I added 2 static routes for both routers, to make sure the packets get routed this way in case OSPF / EIGRP or RIP think otherwise.
I have upvoted both answers, but accepted Ron's, since he answered first with a correct set up.
172.31.1.0/24
.