Solve the strange problem of switch grab network printer IP

These days encountered a more bizarre problem: We use the HP printer with a network print server, this print server is more retarded, there is no setup function, only through DHCP to obtain IP, I on the DHCP server to its MAC address binding to an IP, When you set up a printer, you print it through this IP. However, a few days ago I suddenly found that some people can print, some people can't print. Feeling very strange, so to one of the colleagues to set up, the print driver deleted, and then reload, or can not print! Later found in the installation of the printer prompts what "printer network settings and native settings conflict" and so on the error, thinking that the system is a problem? Use the "Ultimate method" to the system to reload, and then install the printer driver, it is very smooth, loaded on! However, still cannot print ... I was completely dizzy.

Isn't he one of the problems? Asked the person next to him, tried, one or two people can print, most can not print, thought, is they access to the switch there is a problem? Most people who can't print are concentrated on that switch. But the switch also has the ability to print AH. And they just can't print, it's normal to connect to the server for work. What the hell is going on here? It suddenly occurred to me that the machine can not print ping the IP of the printer, get the TTL value will change, is there a device on the Internet with this IP? On the machine that has the problem to start running cmd,ping x.x.x.x,arp-a, sure enough to find the problem! The MAC address is not the MAC address of the printer. "Man" robbed the printer's ip!. We must find him out.

I used iptables on the proxy server to ban this MAC address all the information, I thought, someone should come to me said that can not go online. The result was a weekend, Monday came everyone still told me can't print! It's crazy! So, send a mass mail to everyone, let them give me feedback MAC address and IP address information, get most of the reply, but still did not find this conflict device or computer. Later downloaded from the Internet MAC address scanner small software, but this software is weaker, can only sweep to Windows machine, can not scan the desired information. The next section to MAC address scanner, this has the information I want! Found another Mac closer to the conflicting Mac, this Mac LAN only two, what is this device? On the IEEE Web site to find out that it is 3Com equipment, thinking of 3com equipment, the company has access to only a few switches, is it it? So, open IE, even one of the IP, opened! Sure it is! The original is the switch ah ... Can even that conflict of IP, or not even, because there is a printer, it is possible to connect the printer, and then dial the printer's network cable, and then even. It's open, it's a switch! Oh,my God, finally caught the culprit! The switch grabbed the printer's ip!. This is good to do, manually assign IP to it, and then restart the print server, O K, conflict resolution.

Then seriously think, why this switch will rob the printer's IP? May and that day I change the DHCP server's motherboard, after replacing the motherboard, the onboard Nic Mac also changed, for some reason, the DHCP server did not start normally, after the startup, the print server may be abnormal state, the switch robbed this IP.

Alas.. Finally to solve the problem of the broken! Also found a useful gadget for Coley MAC address scanner! section of other software is shareware, you can try, but to use all the features or to spend money to buy, this gadget is completely free, thank you it solved my problem!