Help!!!

[Webwally]

Hi,

Does anyone know how to save an MTU setting in Mandrake 10.1? Reason being that my ISP is AOL and my MTU settings need to be 1400. They are 1500 by default, no probs in setting the MTU to 1400, upon rebooting the MTU goes back to 1500. Don't know how to save it.

[root@Mandrake jason]# ifconfig eth0
eth0 Link encap:Ethernet HWaddr 00:E0:4D:85:C4:FF
inet addr:10.0.0.3 Bcast:255.255.255.255 Mask:255.0.0.0
inet6 addr: fe80::2e0:4dff:fe85:c4ff/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1400 Metric:1
RX packets:5528 errors:0 dropped:0 overruns:0 frame:0
TX packets:6226 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:2364445 (2.2 Mb) TX bytes:763605 (745.7 Kb)
Interrupt:5 Base address:0xc000
Cheers

Jason

[mugstar]

AFAIK:
(as root)
Take the interface down: `ifdown eth0`
Set the MTU: `ifconfig eth0 mtu 1400`
Bring the interface back up`ifup eth0`

Hopefully if you reboot and do `ifconfig eth0` the setting should be as you want.

`man ifconfig` for more.

[Guest]

Hi,

Tried the above, did'nt keep the setting.

Jason

[mugstar]

Hokay.

Try editing /sys/class/net/eth0/mtu as root and make sure the correct value is there.

[Rhakios]

From looking at the difference between Mandrake and SuSE, MTU can be set by editing /etc/sysconfig/network-scripts/ifcfg-eth0

At the moment it probably says something like

Code: Select all

DEVICE=eth0
BOOTPROTO=static
IPADDR=192.168.0.100
NETMASK=255.255.255.0
NETWORK=192.168.0.0
BROADCAST=192.168.0.255
ONBOOT=yes
METRIC=10
MII_NOT_SUPPORTED=yes


Add a line that says

Code: Select all

MTU='1400'


and that should stick after a reboot. Of course, you will need root permissions to edit the file.

[Guest]

Hi,
I entered /sys/class/net/eth0/mtu and got a message saying permission denied.

[Andy]

Stupid question, I know, but did you try to access it as root?

AndyH

[Guest]

Hi Andy,

Yes I did.

Jason

[nelz]

/sys is a virtual filesystem, like /proc. any changes you make there won't survive a reboot. Rhakios' suggestion is the way to do it.

[Guest]

Hi,

Tried this, no sign of ifcfg-eth0 in this path /etc/sysconfig/network-scripts/ifcfg-eth0

Jason

[mugstar]

The file ifcfg-eth0 is in the directory /etc/sysconfig/network-scripts/

Where does /sys/class/net/eth0/mtu take the value from if it's not included in /etc/sysconfig/network-scripts/ifcfg-eth0?

(Just curious...)

[Rhakios]

Then do you have ifcfg-eth-anything-at-all? If you don't, I'm rather curious as to how your ethernet card works at all. SuSE usually names the ifcfg file after the mac address of the card, but my version of Mandrake (10.1 official) uses eth0. Have a look in /etc/sysconfig/network-scripts and see what else is there.

[Guest]

Hi,
found /etc/sysconfig/network-scripts/ifcfg-eth0, opened the file but could not edit it. Did'nt have permission!

Jason

[Guest]

Hi all,

Managed to edit the file and enter MTU=1400. Rebooted and guess what? Hooooray!!! It did as you said! rebooted at MTU 1400. All I can say is that you lads certainly know your stuff!!! and I'm greatfull for the help you all gave me!

P.S What a great website this is!!!

Cheers

Jason

[Guest]

**** you