Comment 0 for bug 1401141

Release: Ubuntu 14.04.1 LTS
Version: 4.2.4-7ubuntu12

The current DHCP package in Ubuntu can't handle IPoIB clients. For IB, Mellanox uses IPoIB, which is “Eth emulator” for the control path. DHCP is not working in this mode without a patch for DHCP server.

=====================
From IETF documentation:
http://git.openfabrics.org/pub/scm/~rupertd/docs/release_notes/ipoib_release_notes.txt
...
"Note: Two patches for DHCP are required for supporting IPoIB. The patch files
for DHCP v3.0.4 are available under the docs/dhcp/ directory.

Standard DHCP fields holding MAC addresses are not large enough to contain an
IPoIB hardware address. To overcome this problem, DHCP over InfiniBand messages
convey a client identifier field used to identify the DHCP session. This client
identifier field can be used to associate an IP address with a client identifier
value, such that the DHCP server will grant the same IP address to any client
that conveys this client identifier."
...
"In order to use a DHCP client identifier, you need to first create a
configuration file that defines the DHCP client identifier. Then run the DHCP
client with this file using the following command:
dhclient cf <client conf file> <IB network interface name>
Example of a configuration file for the ConnectX (PCI Device ID 26428), called
dhclient.conf:Ubuntu 14.04.1 LTS
# The value indicates a hexadecimal number
interface "ib1" {
send dhcp-client-identifier
ff:00:00:00:00:00:02:00:00:02:c9:00:00:02:c9:03:00:00:10:39;
}
"