DHCP protocol packets

• XID  : randomly generated a string, two packets have the same xid they belong to the same session description
• Ciaddr  : The client will send a request to your ip address in here
• Yiaddr  : ip address of the server will want to assign to the client on here
• Siaddr  : Generally the ip address of the server but be careful.! According openwrt comments given by the source, when the source address of the packet, siaddr, option> server_id field inconsistent (there are forwarded through cross-subnet), generally considered option> srever_id field for the real server ip, siaddr there may be times a jump in a routing route IP (wireshark capture the figure is also marked as siaddr nextserver ip address)
• Chaddr  : client mac address
• The giaddr  : If you need to cross-subnet DHCP address distribution, then fill in here through the router ip address
• Sname  : primary domain name server
• Options  : free to add a section for storing information response to client requests to the server information and server