Help!!!

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Help!!!

Postby Webwally » Thu Apr 21, 2005 3:08 pm

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
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RE: Help!!!

Postby mugstar » Thu Apr 21, 2005 5:34 pm

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.
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RE: Help!!!

Postby Guest » Thu Apr 21, 2005 6:06 pm

Hi,

Tried the above, did'nt keep the setting.

Jason
Guest
 

RE: Help!!!

Postby mugstar » Thu Apr 21, 2005 7:02 pm

Hokay.

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

Postby Rhakios » Thu Apr 21, 2005 7:11 pm

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.
Bye, Rhakios
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RE: Help!!!

Postby Guest » Thu Apr 21, 2005 8:43 pm

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

Postby Andy » Thu Apr 21, 2005 8:51 pm

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

AndyH
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Postby Guest » Thu Apr 21, 2005 8:54 pm

Hi Andy,

Yes I did.

Jason
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Postby nelz » Thu Apr 21, 2005 8:54 pm

/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.
"Insanity: doing the same thing over and over again and expecting different results." (Albert Einstein)
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Postby Guest » Thu Apr 21, 2005 8:58 pm

Hi,

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

Jason
Guest
 

Postby mugstar » Thu Apr 21, 2005 9:00 pm

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...)
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Postby Rhakios » Thu Apr 21, 2005 10:56 pm

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.
Bye, Rhakios
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Postby Guest » Fri Apr 22, 2005 8:53 am

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

Jason
Guest
 

Postby Guest » Fri Apr 22, 2005 9:36 am

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
 

Postby Guest » Fri Apr 29, 2005 7:17 pm

**** you
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