How do I change my MTU?

Shadowmeph · 2008-06-01 18:35:04

I have been having problems lately with my internet I am behind Smoothwall hardware firewall and things don't look right to me like this

eth0      Link encap:Ethernet  HWaddr 00:1B:21:17:06:E9  
          inet addr:192.168.0.197  Bcast:192.168.0.255  Mask:255.255.255.0
          inet6 addr: fe80::21b:21ff:fe17:6e9/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:496540 errors:0 dropped:0 overruns:0 frame:0
          TX packets:627596 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:195333716 (186.2 Mb)  TX bytes:680779592 (649.2 Mb)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          [b]UP LOOPBACK RUNNING  MTU:16436  Metric:1[/b]
          RX packets:26 errors:0 dropped:0 overruns:0 frame:0
          TX packets:26 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:2494 (2.4 Kb)  TX bytes:2494 (2.4 Kb)

does that look normal? I disconnected my firewall earlier and went to the dsl reports site and did the tweak test it showed that my Arch linux systems MTU was like 576 or close to that then when I reconnected the firewall.
this is the infconfig without the firewall

eth0      Link encap:Ethernet  HWaddr 00:1B:21:17:06:E9  
          inet addr:xxx.xxx.xxx.xxx.  Bcast:255.255.255.255  Mask:255.255.252.0
         [b] UP BROADCAST RUNNING MULTICAST  MTU:576  Metric:1[/b]
          RX packets:2122 errors:0 dropped:0 overruns:0 frame:0
          TX packets:14 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:100 
          RX bytes:130036 (126.9 Kb)  TX bytes:2741 (2.6 Kb)

lo        Link encap:Local Loopback  
          inet addr:127.0.0.1  Mask:255.0.0.0
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:0 errors:0 dropped:0 overruns:0 frame:0
          TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:0 (0.0 b)  TX bytes:0 (0.0 b)

Last edited by Shadowmeph (2008-06-01 19:27:58)

pyther · 2008-06-01 19:04:27

inet addr:xxx.xxx.xxx.xxx.

is that what is shows or did you blank it out?

Shadowmeph · 2008-06-01 19:06:17

pyther wrote:

inet addr:xxx.xxx.xxx.xxx.
is that what is shows or did you blank it out?

I blanked it out ( a little bit paranoid)

Shadowmeph · 2008-06-01 19:28:44

I need to change my MTU from the 576 to 1500

arlite · 2008-06-01 19:45:56

mtu is usually set inside the /etc/rc.conf

example:
eth0="xxx.xxx.xxx.xxx netmask yyy.yyy.yyy.yyy broadcast zzz.zzz.zzz.zzz mtu 1500"

but i'm not sure about your firewall

pyther · 2008-06-01 19:49:01

Well from what I can tell your ifconfig configuration looks good.

Usually the MTU is set at the router level, maybe modem level, so I'd check your router or modem.

Shadowmeph · 2008-06-01 19:54:44

ok that actually helped me allot I have set it thank you

Arch Linux

#1 2008-06-01 18:35:04

How do I change my MTU?

#2 2008-06-01 19:04:27

Re: How do I change my MTU?

#3 2008-06-01 19:06:17

Re: How do I change my MTU?

#4 2008-06-01 19:28:44

Re: How do I change my MTU?

#5 2008-06-01 19:45:56

Re: How do I change my MTU?

#6 2008-06-01 19:49:01

Re: How do I change my MTU?

#7 2008-06-01 19:54:44

Re: How do I change my MTU?

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