Physical Network Topology
As shown in the figure, two CE12800 directly connected devices, two different IP addresses are configured on device A, and the directly connected IP address is configured on device B.
Figure 1-1 Direct connection devices cannot ping successfully
Fault Description
The device A can ping device B as follows:
[~R4U13-CE12800]
ping 102.1.1.101
PING 102.1.1.101: 56 data bytes, press CTRL_C to break
Reply from 102.1.1.101: bytes=56 Sequence=1 ttl=254 time=2 ms
Reply from 102.1.1.101: bytes=56 Sequence=2 ttl=254 time=2 ms
When the source IP address is an interface IP address on the device A, the ping cannot be pinged. The details are as follows:
[~R4U13-CE12800]
ping -a 102.1.1.1 102.1.1.101
PING 102.1.1.101: 56 data bytes, press CTRL_C to break
Request time out
Request time out
Request time out
Request time out
Request time out
--- 102.1.1.101 ping statistics ---
5 packet(s) transmitted
0 packet(s) received
100.00% packet loss
Configuration Files
dfs-group 1
source ip 10.1.1.1
#
ip vpn-instance huawei-1
ipv4-family
#
ip vpn-instance huawei-2
ipv4-family
#
ip vpn-instance huawei-3
ipv4-family
#
bridge-domain 10
vxlan vni 5010
#
interface Vlanif100
ip binding vpn-instance huawei-1
ip address 100.1.1.2 255.255.255.0
#
interface Vlanif200
ip binding vpn-instance huawei-2
ip address 101.1.1.2 255.255.255.0
#
interface Vlanif300
ip binding vpn-instance huawei-3
ip address 102.1.1.101 255.255.255.248
#
interface Vlanif1000
ipv6 enable
ip address 100.100.1.102 255.255.255.0
ipv6 address 1000:1000::102/64
ipv6 address auto link-local
vrrp vrid 1 virtual-ip 100.100.1.101
vrrp6 vrid 2 virtual-ip FE80::1 link-local
vrrp6 vrid 2 virtual-ip 1000:1000::1000
#
interface Eth-Trunk1
peer-link 1
port vlan exclude 1000
#
interface Eth-Trunk10
port default vlan 1000
dfs-group 1 m-lag 500
#
interface Eth-Trunk10.1 mode l2
encapsulation dot1q vid 4000
bridge-domain 10
#
interface 10GE2/0/1
port link-type trunk
port trunk allow-pass vlan 100 200 300
device transceiver 10GBASE-FIBER
#
interface 10GE2/0/20
eth-trunk 10
device transceiver 10GBASE-FIBER
#
interface 10GE2/0/22
eth-trunk 1
device transceiver 10GBASE-FIBER
#
interface LoopBack1
ip address 5.5.5.5 255.255.255.255
#
interface Nve1
source 5.5.5.5
vni 5010 head-end peer-list 1.1.1.1
#
bgp 10088
peer 102.1.1.1 as-number 10086
#
ipv4-family unicast
preference 20 20 255
import-route direct
peer 102.1.1.1 enable
#
ipv4-family vpn-instance huawei-1
peer 100.1.1.1 as-number 10086
#
ipv4-family vpn-instance huawei-2
peer 101.1.1.1 as-number 10086
#
ipv4-family vpn-instance huawei-3
peer 102.1.1.1 as-number 10086
#
ospf 100
import-route direct
import-route static
area 0.0.0.0
network 5.5.5.5 0.0.0.0
network 102.1.1.0 0.0.0.255
#
Troubleshooting Procedure
Step 1 View the routing table and ARP entries in this segment. The data is normal. The details are as follows:
[~R4U13-CE12800]
dis ip routing-table 102.1.1.101
Proto: Protocol Pre: Preference
Route Flags: R - relay, D - download to fib, T - to vpn-instance
------------------------------------------------------------------------------
Routing Table : _public_
Summary Count : 1
Destination/Mask Proto Pre
Cost Flags
NextHop Interface
102.1.1.96/29 Direct 0
0
D 102.1.1.100 Vlanif300
[~R4U13-CE12800]
[~R4U13-CE12800]dis arp | in 102.1.1.101
ARP Entry Types: D - Dynamic, S - Static, I - Interface
EXP: Expire-time
IP ADDRESS MAC ADDRESS EXP(M)
TYPE/VLAN INTERFACE VPN-INSTANCE
------------------------------------------------------------------------------
102.1.1.101 200b-c73c-9337 13
D/300 10GE1/0/1
------------------------------------------------------------------------------
Total:52 Dynamic:40
Static:0 Interface:12
Step 2 The packet can be sent out normally from the interface, but there is no return packet, as follows:
<R4U13-CE12800>
dis int 10g 1/0/1
10GE1/0/1 current state : UP (ifindex: 64)
Line protocol current state : UP
Description:
Switch Port, PVID : 1, TPID : 8100(Hex), The Maximum Frame
Length is 9216
Internet protocol processing : disabled
IP Sending Frames' Format is PKTFMT_ETHNT_2, Hardware address is 200b-c73c-9301
Port Mode: COMMON FIBER, Port
Split:
DISABLE
Speed:
10000,
Loopback:
NONE
Duplex:
FULL,
Negotiation:
DISABLE
Input Flow-control: DISABLE, Output
Flow-control: DISABLE
Mdi: -#goback
Last physical up time : 2018-07-02 08:37+02:00
Last physical down time : 2018-07-02 08:37+02:00
Current system time: 2018-07-02 08:37+02:00
Statistics last cleared:2018-07-02 08:37+02:00
Last 300 seconds input rate: 148 bits/sec, 0 packets/sec
Last 300 seconds output rate: 367 bits/sec, 0 packets/sec
Input peak rate 148 bits/sec, Record time: 2018-07-02 08:37+02:00
Output peak rate 367 bits/sec, Record time: 2018-07-02 08:37+02:00
Input
:
536
bytes,
3 packets
Output:
1383
bytes,
10 packets
Input:
Unicast:
2,
Multicast:
1
Broadcast:
0,
Jumbo:
0
Discard:
0,
Frames:
0
Pause:
0
Total
Error:
0
CRC:
0,
Giants:
0
Jabbers:
0, Fragments: 0
Runts:
0,
DropEvents:
0
Alignments:
0,
Symbols:
0
Ignoreds:
0
Output:
Unicast:
7, Multicast: 3
Broadcast:
0,
Jumbo:
0
Discard:
0, Buffers
Purged:
0
Pause:
0
Input bandwidth utilization threshold : 90.00%
Output bandwidth utilization threshold: 90.00%
Last 300 seconds input utility rate: 0.01%
Last 300 seconds output utility rate: 0.01%
From the current port count, the message has been sent, but the message has not returned.
Step 3 Query the routing entries of the peer device, as follows:
[~R4U13-CE12800-SWITCH-A]
dis ip routing-table vpn-instance huawei-3 102.1.1.1
[~R4U13-CE12800-SWITCH-A]
The routing entry does not exist. Add the corresponding routing entry:
[~R4U13-CE12800-SWITCH-A] ip route-static vpn-instance huawei-3 102.1.1.1 255.255.255.248 102.1.1.100
After the routing entry is added, you can ping normally.
[~R4U13-CE12800]
ping -a 102.1.1.1 102.1.1.101
PING 102.1.1.101: 56 data bytes, press CTRL_C to break
Reply from 102.1.1.101: bytes=56 Sequence=1 ttl=254 time=3 ms
Reply from 102.1.1.101: bytes=56 Sequence=2 ttl=254 time=2 ms
Reply from 102.1.1.101: bytes=56 Sequence=3 ttl=254 time=2 ms
Reply from 102.1.1.101: bytes=56 Sequence=4 ttl=254 time=1 ms
Reply from 102.1.1.101: bytes=56 Sequence=5 ttl=254 time=3 ms
--- 102.1.1.101 ping statistics ---
5 packet(s) transmitted
5 packet(s) received
0.00% packet loss
round-trip min/avg/max = 1/2/3 ms
----End
Root Cause
When the device is pinged with the source IP address, the source IP address and the peer device are not in the same network segment. As a result, packets are sent without a routing entry.
