GRE Tunnel between Huawei CE6850 & Cisco 6509

[c.walsh]

I am trying to configure a GRE tunnel between a CE6850 & a Cisco Catalyst 6509 switch.
However the tunnel will not come up on the 6850, although i have layer 3 connectivity between the source & destination ip address's.

There are No Firewalls in between

Has anyone done this before?

CE6850 configuration...
interface Tunnel0
 ip address 192.168.121.1 255.255.255.252
 tunnel-protocol gre
 source 10.163.50.14
 destination 10.34.75.2

Cisco 6509 configuration...
interface Tunnel0
 ip address 192.168.121.2 255.255.255.252
 tunnel source 10.34.75.2
 tunnel destination 10.163.50.14

<Huawei-6850>dis int t0
Tunnel0 current state : DOWN (ifindex: 156)
Line protocol current state : DOWN
Route Port,The Maximum Transmit Unit is 1500, Current BW: 65.53Kbps
Internet Address is 192.168.121.1/30
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: 2017-08-04 15:05:46+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 : --

Cisco-6509#show int t0
Tunnel0 is up, line protocol is up
  Hardware is Tunnel
  Internet address is 192.168.121.2/30
  MTU 17868 bytes, BW 100 Kbit, DLY 50000 usec,
     reliability 255/255, txload 1/255, rxload 1/255
  Encapsulation TUNNEL, loopback not set
  Keepalive not set
  Tunnel source 10.34.75.2, destination 10.163.50.14
  Tunnel protocol/transport GRE/IP
    Key disabled, sequencing disabled
    Checksumming of packets disabled
  Tunnel TTL 255, Fast tunneling enabled
  Tunnel transport MTU 1476 bytes
  Last input 03:42:34, output 00:21:58, output hang never
  Last clearing of "show interface" counters never
  Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0
  Queueing strategy: fifo
  Output queue: 0/0 (size/max)
  5 minute input rate 0 bits/sec, 0 packets/sec
  5 minute output rate 0 bits/sec, 0 packets/sec
  L2 Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes
  L3 in Switched: ucast: 0 pkt, 0 bytes - mcast: 0 pkt, 0 bytes mcast
  L3 out Switched: ucast: 0 pkt, 0 bytes mcast: 0 pkt, 0 bytes
     54 packets input, 4660 bytes, 0 no buffer
     Received 0 broadcasts (0 IP multicasts)
     0 runts, 0 giants, 0 throttles
     0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored, 0 abort
     4594 packets output, 221652 bytes, 0 underruns
     0 output errors, 0 collisions, 0 interface resets
     0 output buffer failures, 0 output buffers swapped out

[Richard Burts]

I have done lots of GRE tunnels with Cisco but have no experience with CE6850. I do not see any obvious issues with the partial config that you have posted. Perhaps if we saw a more complete config we might be able to spot some issue (are there any access lists on interfaces that impact the GRE, etc).

I do note that the CE6850 has enabled keepalives on the GRE tunnel while 6509 has not enabled keepalives on the GRE tunnel. That should not be an issue (keepalives are not required to be symmetrical on GRE tunnels), but you might want to make both sides be consistent to eliminate possibilities of errors.

In my experience one of the most common source of problems in bringing up GRE tunnels is that the devices may not have proper IP connectivity. So as a first step in troubleshooting I would suggest that you verify that  CE6850 can ping 10.34.75.2 using 10.163.50.14 as the source address. And verify that 6509 can ping 10.163.50.14 using 10.34.75.2 as the source address.

HTH

Rick