[rhos-list] br-ex bridge and persistent MAC address

Ian Wienand iwienand at redhat.com
Wed Jul 10 05:07:21 UTC 2013


Hi,

I installed RDO on RHEL, and have br-ex and br-int bridges setup by
Quantum I presume.  This mini-server only has one NIC, so I want to
put em1 into the br-ex bridge and give the bridge the same address on
the network.

So I tried the following

--- /etc/sysconfig/nework-scripts/ifcfg-br-ex
DEVICE=br-ex
ONBOOT=no
DEVICETYPE=ovs
TYPE=OVSBridge
OVSBOOTPROTO=dhcp
OVSDHCPINTERFACES=em1
OVS_EXTRA="set Bridge br-ex other-config:hwaddr=\"xx:xx\""
---

--- /etc/sysconfig/network-scripts/ifcfg-em1 ---
DEVICE="em1"
BOOTPROTO="none"
DEVICETYPE="ovs
TYPE=OVSPort
OVS_BRIDGE=br-ex
NM_CONTROLLED=no
ONBOOT="yes"
---

so "ifup em1" brings the physical NIC device up, automatically brings
the bridge up and gets a dhcp address -- the problem being the MAC
address of br-ex is constantly changing so my dhcp server can't assign
it the right address.

I can see that it knows about it the hwaddr config option

---
# ovs-vsctl list bridge br-ex
_uuid               : 067c69b1-fed6-49ec-9180-b3d9e3c631aa
controller          : []
datapath_id         : "000026b0a55452c8"
datapath_type       : ""
external_ids        : {}
fail_mode           : []
flood_vlans         : []
flow_tables         : {}
mirrors             : []
name                : br-ex
netflow             : []
other_config        : {hwaddr="26:b0:a5:54:52:c8"}
ports               : [25a0c131-b259-4a2d-94a8-ed8ac95323cd, 49e60140-868b-42dd-bbc3-9431796668c1]
protocols           : []
sflow               : []
status              : {}
stp_enable          : false
---

but yet the MAC address remains randomly generated

---
# ifconfig br-ex
br-ex     Link encap:Ethernet  HWaddr BA:41:5A:A5:33:82  
          inet addr:192.168.0.22  Bcast:192.168.0.255  Mask:255.255.255.0
---

Any suggestions welcome!

-i




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