When cannot ping the server through S5700HI VLL network.

Issue Description

1. Topology
Client — L3VPN — NE40E(PE) —- S5700HI-1(P) — S5700HI(PE) —– Access Switch — Server

2. Problem description
Configure VLL service between NE40E and S5700HI. Found some servers can ping and some cannot ping from client.

Alarm Information


Handling Process

1. Ping Server from access switch and it is ok.
2. Ping from NE40E and it is failed. Make traffic statistics on access switch to check icmp pakcet reach or not.
Result: No icmp packet reach
3. Check that there is no ARP table on NE40E. So the problem is ARP learning issue. Make ARP pakcets statistics on access switch. No arp request arrives.
4. on S5700HI P devices, capture packets on the port connects to NE40E. And found there is no arp packet.
5. Check the port configuration on NE40E. Customer configure QinQ sub interfaces. One command “arp broadcast enable” is missed.
interface Virtual-Ethernet1/1/1.100
control-vid 310 qinq-termination
qinq termination pe-vid 1002 ce-vid 310
ip binding vpn-instance l3v-sermgmt
ip address X.X.X.X
arp broadcast enable

Root Cause

1.Configure Issue
2. Network Issue


For sub interface and QinQ sub interface, command “arp broadcast enable” must be configured. Or device cannot send out the arp packets.