IP Address Swapping Within a Single VLAN


The following description provides recommendations for swapping IP addresses among servers. IP transfers can be performed among servers located within the same VLAN, i.e., one logical network.


When changing the MAC address associated with a specific IP (transferring from one server to another), it is necessary to inform the router of the change using Gratuitous ARP.

In Linux, the tool send_arp from the heartbeat package is used for this purpose. Send_arp is considered a reliable and functional tool. After allocating the IP to the new server, simply execute the following command on the new server:

send_arp eth0 TRANSFERRED_IP auto not_used not_used

Alternatively, you can announce the change using the arping command:

arping -U -I eth0 -c 3 NEW_SERVER_IP
Note: The MasterDC router has an ARP cache, which may cause delays when swapping IPs.

If anything does not work during this process, feel free to request the deletion of the ARP record via email at support@master.cz at any time.

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