ibft and bridge

Issues related to configuring your network
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drookie
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Joined: 2016/01/16 09:45:53

ibft and bridge

Post by drookie » 2017/03/09 09:03:32

Hi,

I'm using Centos to launch KVM hypervisors and a bunch ov VMs. Centos itself is installed on an iSCSI target disk, and is booting via iSCSI. I want to add the public bridged connectivity to the guests, however I didn't figure out the way to do this. Is this even possible ? I tried to add the ibft0 interface to the bridge, but after that Centos refused to boot, so I just had to rollback this.

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jlehtone
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Location: Finland

Re: ibft and bridge

Post by jlehtone » 2017/03/09 10:13:18

I'm not familiar with the iSCSI boot. Am I correct that something establishes a connection and iSCSI session before bootloader/kernel file is accessed?

Is the ibft0 the only interface in the host? How/when does management of interface transfer from initiator to the Linux?

Do you use NetworkManager.service or network.service?

drookie
Posts: 9
Joined: 2016/01/16 09:45:53

Re: ibft and bridge

Post by drookie » 2017/03/09 13:17:10

Yup, it's the intel iSCSI loader firmware that established the connection to the iSCSI target and provides a block device to get the bootstrap from. Linux kernel then has a set of options to indicate that the iBFT (iSCSI Boot Firmware Table) is available, so Linux uses the information contained in it to boot up. The hardware network adapter then changes it's name to ibft0.

Both network and Network.Manager units are running, but I'm more like to edit the configuration files in the /etc/sysconfig/network-scripts directly. I tried using nmcli to create a bridge with ibft0, but got nowhere, br0 was created by it's interface list is empty, and

Code: Select all

nmcli con add type bridge-slave ifname ibft0 master bridge-br0
just does nothing. Well... not exaclty nothing, for some reason it produces useless device bridge-slave-ibft0.

I can also put the interface ibft0 into a bridge br0 and migrate the interface ip to br0, but this just breaks the iSCSI.

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jlehtone
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Location: Finland

Re: ibft and bridge

Post by jlehtone » 2017/03/09 21:09:37

I would guess that interfaces have to be defined earlier, like a bond seems to be in here:
viewtopic.php?t=58155

There are both 'bond' and 'bridge' in:
http://man7.org/linux/man-pages/man7/dr ... ine.7.html

Then again, http://ipxe.org/appnote/ibft contains note 5.

I would experiment with those kernel command line options.

drookie
Posts: 9
Joined: 2016/01/16 09:45:53

Re: ibft and bridge

Post by drookie » 2018/12/28 11:39:46

ip=:::::br0:dhcp bridge=br0:ens5 as kernel arguments.

So in the end it's possible. I guess it's possible with ibft, my my goal was to remove ibft in order to boot from Mellanox FlexBoot which is iPXE _and_ have a brudge after booting which the boot interface is a part of.

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