Jun 12th, 2010
How to set the MTU for network interface
How to set the MTU for network interface
The MTU can be set by editing the configuration file for the device. To see the devices you have use the ifconfig command:
eth0 Link encap:Ethernet HWaddr 08:00:27:7d:bd:61
inet addr:10.0.2.15 Bcast:10.0.2.255 Mask:255.255.255.0
inet6 addr: fe80::a00:27ff:fe7d:bd61/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:153050 errors:54 dropped:0 overruns:0 frame:0
TX packets:86060 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:168036386 (168.0 MB) TX bytes:9165208 (9.1 MB)
Interrupt:10 Base address:0xd020
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:8 errors:0 dropped:0 overruns:0 frame:0
TX packets:8 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:480 (480.0 B) TX bytes:480 (480.0 B)
Alternatively, you can use the ip command:
1: lo: mtu 16436 qdisc noqueue state UNKNOWN
link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
2: eth0: mtu 1500 qdisc pfifo_fast state UNKNOWN qlen 1000
link/ether 08:00:27:7d:bd:61 brd ff:ff:ff:ff:ff:ff
The interface eth0 has an MTU set to 1500 bytes. To change the setting temporarily (to 1200 in this example) issue the following command as root:
To make the setting permanent for eth0, edit the configuration file /etc/sysconfig/network-scripts/ifcfg-eth0 and add the line MTU=1200
