Summary
This article describes how to enable promiscuous mode on a physical Network Interface Card (NIC).
Background
In a network, promiscuous mode allows a network device to intercept and read each network packet that arrives in its entirety. This mode of operation is sometimes given to a network snoop server that captures and saves all packets for analysis (for example, when monitoring network usage).
Procedure
1. To enable the promiscuous mode on the physical NIC, run the following command on the XenServer text console:
# ifconfig eth0 promisc
2. Run the ifconfig command and notice the outcome:
eth0 Link encap:Ethernet HWaddr 00:1D:09:08:94:8A
inet6 addr: fe80::21d:9ff:fe08:948a/64 Scope:Link
UP BROADCAST RUNNING PROMISC MULTICAST MTU:1500 Metric:1
RX packets:23724 errors:0 dropped:0 overruns:0 frame:0
TX packets:7517 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2169478 (2.0 MiB) TX bytes:5423377 (5.1 MiB)
Interrupt:17
To disable promiscuous mode on the physical NIC, run the following command on the XenServer text console:
# ifconfig eth0 –promisc
Run the ifconfig command again and notice that promiscuous mode is now disabled.
