NE40 cannot ping eudemon1000 firewall. No one moves the device. It is problematic suddenly. NE40 and the firewall are connected through Gigabit Ethernet interface and there is no transmission device ne40(g4/0/3)-----eudemon1000. NE40 can ping its interface g4/0/3 192.168.100.5, but it cannot ping opposite address 192.168.100.6.
Check ARP table and it is found that NE40 does not learn ARP of opposite address. Opposite ARP can be learned on the firewall. Change the port and it is still problematic. Change the slot and it is not solved.
Change NE40 and there is no problem. The firewall and the intermediate link are not problematic.
Static bind ARP and it is solved.
Check all configuration of the device and it is found that someone configures arp mac-binding match command. It has to configure static ARP.
Configure arp mac-binding match under VLAN. ARP binds check function and it to be opened. If checking ARP binding table fails, ARP request packet is directly discarded and no matching ARP response is created. It only applies to common VLAN. Super-VLAN has no member interface, it is taken as not open ARP binding.