ConnectX5 RDMA_CM_EVENT_ADDR_ERROR, error -110

I face the problem of RDMA_CM_EVENT_ADDR_ERROR, error -110 when I use rping to test the connection of two servers.

server$ rping -s -a 15.15.15.6
client$ rping -c -a 15.15.15.6

The error on the client is :

client
created cm_id 0x5606399430c0
cma_event type RDMA_CM_EVENT_ADDR_ERROR cma_id 0x5606399430c0 (parent)
cma event RDMA_CM_EVENT_ADDR_ERROR, error -110
waiting for addr/route resolution state 1
destroy cm_id 0x5606399430c0
destroy cm_id 0x5606399430c0

There may be address resolve error but I don’t know how to configure it. Can you tell me what’s wrong with my configuration? Thank you very much.

I have configured the network interface as :

auto lo
iface lo inet loopback
mtu 9000

auto ens16f0
iface ens16f0 inet static
    address 15.15.15.6
    netmask 255.255.255.0

auto ens16f1
iface ens16f1 inet static
    address 15.15.15.7
    netmask 255.255.255.0

When I use route -n it shows:

ernel IP routing table
Destination     Gateway         Genmask         Flags Metric Ref    Use Iface
0.0.0.0         192.168.1.1     0.0.0.0         UG    102    0        0 eno1
15.15.15.0      0.0.0.0         255.255.255.0   U     0      0        0 ens16f0
15.15.15.0      0.0.0.0         255.255.255.0   U     0      0        0 ens16f1
169.254.0.0     0.0.0.0         255.255.0.0     U     1000   0        0 eno1
172.17.0.0      0.0.0.0         255.255.0.0     U     0      0        0 docker0
192.168.1.0     0.0.0.0         255.255.255.0   U     102    0        0 eno1

I have installed MLNX_OFED_LINUX-5.6-2.0.9.0-ubuntu18.04-x86_64 on my servers.
I also configure MTU to 9000.

sudo ./mlnxofedinstall --add-kernel-support --without-neohost-backend
sudo /etc/init.d/openibd start

sudo mst start
sudo mst status -v
sudo mlxconfig -d /dev/mst/mt4119_pciconf0 set LINK_TYPE_P1=2 LINK_TYPE_P2=2
sudo mlxconfig -d /dev/mst/mt4119_pciconf0 set HOST_CHAINING_MODE=1
sudo ifconfig ens16f0 mtu 9000
sudo ifconfig ens16f1 mtu 9000
sudo /etc/init.d/networking restart