FreeNAS-11.0-RELEASE VM change the bridge mtu

infinity

Cadet
Joined
Jan 24, 2017
Messages
7
can't start a VM: bridge0 do need a mtu of 9000, because the nic (lagg0 / lacp) has a mtu of 9000.

"bridge0: invalid MTU: 9000(lagg0) != 1500"

Where can I change the mtu for bridge0?

Code:
% ifconfig bridge0
bridge0: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
	ether 02:da:ca:44:0c:00
	nd6 options=9<PERFORMNUD,IFDISABLED>
	groups: bridge 
	id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
	maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
	root id 00:00:00:00:00:00 priority 0 ifcost 0 port 0
	member: tap0 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
			ifmaxaddr 0 port 5 priority 128 path cost 2000000
 
D

dlavigne

Guest
Please create a feature request at bugs.freenas.org and post the issue number here.
 

zvargas

Cadet
Joined
Sep 16, 2019
Messages
3
Would someone from iX be able to confirm if this is still an issue?

I am trying to create the following network topology:

* A physical device ix0
* A VLAN interface, vlan101, with parent interface ix0
* A bridge, bridge101, with member vlan101
* A jail on the VLAN by using vnet with bridge101

NOTE: I want an MTU of 9000 for ALL.

First, I create the VLAN interface using the GUI which results in:

Code:
root@freenas[~]# ifconfig vlan101
vlan101: flags=8943<UP,BROADCAST,RUNNING,PROMISC,SIMPLEX,MULTICAST> metric 0 mtu 9000
    options=600703<RXCSUM,TXCSUM,TSO4,TSO6,LRO,RXCSUM_IPV6,TXCSUM_IPV6>
    ether 00:17:3c:03:8c:d8
    inet 192.168.101.1 netmask 0xffffff00 broadcast 192.168.101.255
    nd6 options=9<PERFORMNUD,IFDISABLED>
    media: Ethernet autoselect (1000Base-KX <full-duplex,rxpause,txpause>)
    status: active
    vlan: 101 vlanpcp: 0 parent interface: ix0
    groups: vlan
root@freenas[~]#


Then, I create a bridge using the GUI which results in:

Code:
root@freenas[~]# ifconfig bridge101
bridge101: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000
    ether 02:17:68:87:cf:65
    nd6 options=9<PERFORMNUD,IFDISABLED>
    groups: bridge
    id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
    maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
    root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
    member: vlan101 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
            ifmaxaddr 0 port 6 priority 128 path cost 2000
root@freenas[~]#


After the bridge creation I see the following message on the terminal:

Code:
bridge101: Ethernet address: 02:17:68:87:cf:65
bridge101: can't disable some capabilities on vlan101: 0x400


Finally, I create a jail that uses vnet by setting the jail advanced configuration 'Network properties' -> 'interfaces' to vnet0:bridge101.

However, on boot the following messages appear:

Code:
epair0a: Ethernet address: 02:ba:d0:00:0a:0a
epair0b: Ethernet address: 02:ba:d0:00:0b:0b
bridge101: invalid MTU: 9000(vnet0.1) != 1500


The MTU for bridge101 is, in fact, not set to the expected 9000:

Code:
root@freenas[~]# ifconfig bridge101
bridge101: flags=8802<BROADCAST,SIMPLEX,MULTICAST> metric 0 mtu 1500
    ether 02:17:68:87:cf:65
    nd6 options=9<PERFORMNUD,IFDISABLED>
    groups: bridge
    id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
    maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
    root id 00:00:00:00:00:00 priority 0 ifcost 0 port 0
    member: vlan101 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
            ifmaxaddr 0 port 6 priority 128 path cost 2000
root@freenas[~]#


The network interface still matches the values set on creation if I edit the bridge interface. Confusingly, clicking 'SAVE' here applies the expected MTU:

Code:
root@freenas[~]# ifconfig bridge101
bridge101: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 9000
    ether 02:17:68:87:cf:65
    nd6 options=9<PERFORMNUD,IFDISABLED>
    groups: bridge
    id 00:00:00:00:00:00 priority 32768 hellotime 2 fwddelay 15
    maxage 20 holdcnt 6 proto rstp maxaddr 2000 timeout 1200
    root id 00:00:00:00:00:00 priority 32768 ifcost 0 port 0
    member: vlan101 flags=143<LEARNING,DISCOVER,AUTOEDGE,AUTOPTP>
            ifmaxaddr 0 port 6 priority 128 path cost 2000
root@freenas[~]#


I realize this thread is for a VM but it appears we are seeing the same issue.

TL;DR Is there a way to persistently set the MTU of a bridge from the GUI?
 

zvargas

Cadet
Joined
Sep 16, 2019
Messages
3
Thanks for the response! I tried this with an 11.3 build but get the same results.

This is the bridge creation:
bridge-creation.png


After boot I get the error:
Code:
bridge101: invalid MTU: 9000(vnet0.1) != 1500


And I can go back and check the configuration for the bridge is set as expected:
bridge-confirmation.png


Again, clicking 'SAVE' here results in the bridge changing to the expected MTU.

Is this the UI support you were referring to?
 

drak3

Cadet
Joined
Sep 11, 2015
Messages
5
I'm also having a very similar issue. would the appropriate course of action be to open/reopen a ticket?
 

jims23211

Cadet
Joined
Jul 14, 2020
Messages
5
I was able to resolve the issue by creating a bridge with the mtu first, then adding the plexserver plugin.
 

drak3

Cadet
Joined
Sep 11, 2015
Messages
5
I was able to resolve the issue by creating a bridge with the mtu first, then adding the plexserver plugin.
I think my situation is complicated by having VLANs involved, too. But I'm wondering if the VMs are getting attached to the bridge before the bridge is attached to the VLAN, because I know FreeNAS wont let me edit a bridge with VMs or Jails attached to it.
 

Samuel Tai

Never underestimate your own stupidity
Moderator
Joined
Apr 24, 2020
Messages
5,398
 

jims23211

Cadet
Joined
Jul 14, 2020
Messages
5
I think my situation is complicated by having VLANs involved, too. But I'm wondering if the VMs are getting attached to the bridge before the bridge is attached to the VLAN, because I know FreeNAS wont let me edit a bridge with VMs or Jails attached to it.

Try this then. In Freenas GUI

Click Network --> Interfaces then ADD
define the bridge with the necessary information.
reboot Freenas
Then try adding a vm or jail.
 

drak3

Cadet
Joined
Sep 11, 2015
Messages
5
Thanks for the tip. Semi-related, would a pre-init script be better to get the network arranged prior to jails and VMs starting?
 
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