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Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 12:56
by NeilP
This is more query and a bug ? I don't know.. I am happy with how my NAS box is working now, but this is just more to ask/ point out that this might be an issue


I did discuss this with raulfg3 on another post here, but under a different thread topic. Just thought I'd give it its own thread. Not for my need but merely for interest, if anyone else had this or it fixed a bug.

I have not changed any hardware.I just pulled the boot HDD, and put in another identical IDE 40gb WD drive and installed the latest XigmaNAS 11.2.0.4 - Omnius (revision 6536)

exact same hardware, as Shigwire and this problem did not occur. Upgrade to XigmasNAS and MTU 9000 stops network access.

If I boot in Shigwire and WebGUI and check Network/LAN Management I can set MTU 9000
Ip address is set static 192.168.2.2
All is good

if I check
Network/LAN management when booted to XigmaNAS
I see the MTU box is blank
if I set 9000, on reboot...although IP address is set as static, I get no IP address.

See photo below.

If I set 1500, all is good.

With Shigwire the system accepted and worked with MTU 9000 jumbo packets with XigmasNAS it does not.

Just intrigued to know why with same hardware it fails with XigmasNAS

Image

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 16:49
by ms49434
It's very easy to bring down an interface by setting an invalid or unsupported MTU value.
Other settings, i.e. kern.ipc.nmbjumbo9/kern.ipc.nmbjumbo16, might impact the support of higher MTU's as well.
Other network components, i.e. a switch, must support jumbo frames as well.
You should start to find out the maximum supported MTU of your current system by manually running

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ifconfig nfe0 mtu value
The value could be anything between 1500 and 9000 (/16k), a binary approach will require a maximum of 13 calls to ifconfig to get the maximum supported MTU.

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 18:45
by NeilP
OK,
Here is what it gives

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Last login: Tue Mar 19 17:41:13 2019
Welcome to XigmaNAS!
backupcifs: ~# ifconfig nfe0 mtu value
ifconfig: ioctl SIOCSIFMTU (set mtu): Invalid argument
backupcifs: ~# 

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backupcifs: ~# ifconfig| grep MTU
	options=80008<VLAN_MTU,LINKSTATE>
backupcifs: ~# 

My query was that it worked wench setting an MTU value with the same hardware, with Shigwire, in that 9000 was set and saved..

Screen Shot 2019-03-19 at 17.45.56.jpg

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 18:50
by NeilP
Been googling around other ifconfig commands to try

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backupcifs: ~# ip 192.168.2.1 | grep mtu
ip: Command not found.
backupcifs: ~# /sbin/ifconfig
nfe0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
	options=80008<VLAN_MTU,LINKSTATE>
	ether 00:16:e6:44:40:ec
	hwaddr 00:16:e6:44:40:ec
	inet 192.168.2.2 netmask 0xffffff00 broadcast 192.168.2.255 
	inet6 fe80::216:e6ff:fe44:40ec%nfe0 prefixlen 64 scopeid 0x1 
	nd6 options=123<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL,NO_DAD>
	media: Ethernet autoselect (1000baseT <full-duplex>)
	status: active
lo0: flags=8049<UP,LOOPBACK,RUNNING,MULTICAST> metric 0 mtu 16384
	options=600003<RXCSUM,TXCSUM,RXCSUM_IPV6,TXCSUM_IPV6>
	inet6 ::1 prefixlen 128 
	inet6 fe80::1%lo0 prefixlen 64 scopeid 0x2 
	inet 127.0.0.1 netmask 0xff000000 
	nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL>
	groups: lo 
backupcifs: ~# 

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 20:08
by raulfg3
Last login: Tue Mar 19 17:41:13 2019
Welcome to XigmaNAS!
backupcifs: ~# ifconfig nfe0 mtu value
ifconfig: ioctl SIOCSIFMTU (set mtu): Invalid argument
backupcifs: ~#
bad, very bad.

ms49434 suggest that you try several times until find optimal MTU Value.

like this:

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ifconfig nfe0 mtu 8000
then try

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ifconfig nfe0 mtu 6000
and so on , to find the max value that your NIC support on BSD 12 (Yes: I know that suppoprt 9000 on BSD 11)


PD:there's nothing that XigmaNAS developers can do if do not work with MTU=9000 is a BSD Problem or a driver problem

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 21:30
by NeilP
Ah OK, I get you now!

doh
I thought the command was probing the system to find the 'Value'

I have tried and ..anything above 1500 gives the Invalid Argument response.

But since the hardware is the same..it does not explain why it seemed to work and set 9000 in Shigwire.
So maybe this is not an error in XigmasNAS, but in fact an error in Shigwire, that showed 9000 being set when in fact it was not supported.

I will boot the box tomorrow back to Shigwire and try to set different MTU from the CLI again.

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 19 Mar 2019 22:32
by ms49434
NeilP wrote:
19 Mar 2019 21:30
Ah OK, I get you now!

doh
I thought the command was probing the system to find the 'Value'

I have tried and ..anything above 1500 gives the Invalid Argument response.

But since the hardware is the same..it does not explain why it seemed to work and set 9000 in Shigwire.
So maybe this is not an error in XigmasNAS, but in fact an error in Shigwire, that showed 9000 being set when in fact it was not supported.

I will boot the box tomorrow back to Shigwire and try to set different MTU from the CLI again.
Do you have any of the below tunables set?

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hw.nfe.msi_disable
hw.nfe.msix_disable
hw.nfe.jumbo_disable

Re: Changing MTU setting in GUI stops IP address being set.

Posted: 20 Mar 2019 07:49
by NeilP
No, not on either N4F Shigwire or XigmaNASz.

In both instances only change was typing in 9000 via WebGUI and hitting Save.
Never used any CLI commands before to change settings within any of the variation from FreeNAS/N4F or now XigmaNAS