Hi.
I would like to configure a GRE tunnel interface between his CloudEngine CE6850-48S4Q-EI and CISCO 6509. I have L3 connectivity between the source and destination IP addresses but the tunnel interface is down on the CE.
Configuration on CE6850:
interface Tunnel0
mtu 1476
ip address 192.168.121.1 255.255.255.252
tunnel-protocol gre
source 10.163.50.14
destination 10.34.75.2
Configuration on CISCO 6509:
interface Tunnel0
ip address 192.168.121.2 255.255.255.252
tunnel source 10.34.75.2
tunnel destination 10.163.50.14
Check to tunnel and is down:
<SCC-Niciman-C01>dis int t0
Tunnel0 current state : DOWN (ifindex: 156)
Line protocol current state : DOWN
Description: ** Niciman VNOC Staff **
Route Port,The Maximum Transmit Unit is 1500, Current BW: 65.53Kbps
Internet Address is 10.255.255.1/30
Encapsulation is TUNNEL, loopback not set
Tunnel source 10.163.50.14 (Vlanif1073), destination 10.34.75.2
Tunnel protocol/transport GRE/IP, key disabled
keepalive enable period 10 retry-times 3
Checksumming of packets disabled
Current system time: 2017-08-08 01:45+01:00 DST
300 seconds input rate 0 bits/sec, 0 packets/sec
300 seconds output rate 0 bits/sec, 0 packets/sec
0 seconds input rate 0 bits/sec, 0 packets/sec
0 seconds output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes
0 input error
0 packets output, 0 bytes
0 output error
Input:
Unicast: 0 packets, Multicast: 0 packets
Output:
Unicast: 0 packets, Multicast: 0 packets
Input bandwidth utilization : --
Output bandwidth utilization : --
I configured the keepalive to 10 seconds and retried but the interface tunnel status was still down.
On CISCO:
interface Tunnel0
keepalive 10 3
On CE:
interface Tunnel1
keepalive period 10
Then removed the MTU 1476 from the Cloud Engine and test again, the tunnel interface ststus was still down.
interface Tunnel0
undo mtu
Root cause:
There is a software limitation for the V100R003C00 version and a loopback eth-trunk must be configured for the GRE tunnel. After this version, there is no need to configure the service type tunnel on the Eth-trunk interface.
The loopback eth-trunk must be configured for the GRE tunnel. Configure an eth-trunk for GRE tunnel (The eth-trunk must have some member ports but no need to connect the port.)
[~SwitchA] interface eth-trunk 1
[*SwitchA-Eth-Trunk1] service type tunnel
[*SwitchA-Eth-Trunk1] quit
Binding the eth-trunk to the tunnel.
[*SwitchC-Tunnel0] binding interface eth-trunk 1
