No relevant resource is found in the selected language.

This site uses cookies. By continuing to browse the site you are agreeing to our use of cookies. Read our privacy policy>

Reminder

To have a better experience, please upgrade your IE browser.

upgrade

Many Alarms About Duplicate IP Addresses Are Generated When the SR NE40 of a Carrier Pings Its Connected Non-Huawei ONUs

Publication Date:  2013-09-03 Views:  72 Downloads:  0
Issue Description
On the MAN of a carrier, Huawei NE40 functions as the SR and gateway to terminate the management VLAN of its connected non-Huawei ONUs. Management packets are lost on non-Huawei ONUs during their proper running. When the NE40 pings non-Huawei ONUs, many alarms about duplicate IP addresses are generated. When the non-Huawei ONUs ping the NE40, ping packets are lost.

On the NE40, a large number of alarms are generated about IP address conflicts between the management IP address of non-Huawei ONUs and the gateway.
%Sep 11 16:25:10 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.53.1 from Vlanif12, source MAC
is 00e0-fc9a-ad3a
%Sep 11 16:25:12 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.127.1 from Vlanif11, source MAC
is 00e0-fc9a-ad3a
%Sep 11 16:25:16 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.127.1 from Vlanif11, source MAC
is 00e0-fc9a-ad3a
%Sep 11 16:25:19 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.127.1 from Vlanif11, source MAC
is 00e0-fc9a-ad3a
%Sep 11 16:25:20 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.5.1 from Vlanif599, source MAC
is 00e0-fc9a-ad3a
%Sep 11 16:25:22 2011 Quidway SRM/5/ARP_DUPLICATE_IPADDR:Slot3 Receive
an ARP packet with duplicate ip address 192.168.49.1 from Vlanif12, source MAC
is 00e0-fc9a-ad3a
Handling Process
Based on analysis of alarms, the possible causes are as follows:
1. Non-Huawei ONUs are configured with the same management IP addresses as the gateway IP address.
2. MAC address conflicts exist on non-Huawei ONUs.
3. Other devices on the network connected to the SR are configured with the same management IP addresses as the gateway IP address, or routing loops exist on the network.
Root Cause
N/A
Solution
1. Verify that all the faulty ONUs use management IP addresses different from the gateway IP address.
2. According to information provided by the vendor and customer, no MAC address conflict exists and the network structure is simple. The network simply implements ONU access management. No other network exists.
3. Based on debugging information on the NE40, an ONU cannot ping the NE40 and alarms about duplicate IP addresses are generated when you ping the ONU's management IP address from the NE40. ARP entries on the NE40 are normal.
ping -vpn-instance CTVPN3200000-JiaoHuanJiGuanLi 192.168.127.189
Reply from 192.168.127.189: bytes=56 Sequence=4 ttl=255 time=542 ms (DUP!)
Reply from 192.168.127.189: bytes=56 Sequence=4 ttl=255 time=542 ms (DUP!)
Reply from 192.168.127.189: bytes=56 Sequence=4 ttl=255 time=543 ms (DUP!)
Reply from 192.168.127.189: bytes=56 Sequence=4 ttl=255 time=544 ms (DUP!)
Reply from 192.168.127.189: bytes=56 Sequence=5 ttl=255 time=132 ms
dis arp interface Vlanif 11 | include 192.168.127.1
Arp Table:
Total number of arp:22 static:0 dynamic:22
IP Address MAC Address VlanID Type VPN-Instance Interface
192.168.127.189 0023-8904-cec0 11 D CTVPN3200000-JiaoHuanJiGuanLi GE3/0/3
192.168.127.186 0023-8904-cf00 11 D CTVPN3200000-JiaoHuanJiGuanLi GE3/0/3
192.168.127.188 0023-8904-cfc0 11 D CTVPN3200000-JiaoHuanJiGuanLi GE3/0/3
4. Analyze the network topology and find that the SR NE40 is connected to an S6500 switch that has QinQ configured. Run the ping -r 192.168.127.189 command on the S6500. The S6500 receives response packets from multiple devices.
After selective QinQ is enabled on the S6500, the S6500 sends response packets using the flooding mechanism. Flooding packets that the non-Huawei ONUs return to the S6500 reach the NE40. The NE40 receives multiple ICMP Echo messages and generates duplicate packet alarms.
5. Inform the vendor of modifying the flooding mechanism on non-Huawei devices by upgrading the ONUs.
Suggestions
1. Many alarms about duplicate IP addresses are generated because addresses conflict or loops occur. The root cause is that the gateway receives repeated ICMP response packets.
2. Configure the connected device to discard flood packets from the S6500.

END