How To Change MTU Value Of Network Interface In Linux

MTU (Maximum Transmission Unit) is related to TCP/IP networking which refers to the size (in bytes) of the largest datagram that can be pass at a time.

We can see current MTU value as below :

$ifconfig eth0

eth0      Link encap:Ethernet  HWaddr 00:0F:EA:91:04:07
         inet addr:192.168.1.2  Bcast:192.168.1.255  Mask:255.255.255.0
         inet6 addr: fe80::20f:eaff:fe91:407/64 Scope:Link
         UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
         RX packets:141567 errors:0 dropped:0 overruns:0 frame:0
         TX packets:141306 errors:0 dropped:0 overruns:0 carrier:0
         collisions:0 txqueuelen:1000
         RX bytes:101087512 (96.4 MiB)  TX bytes:32695783 (31.1 MiB)
         Interrupt:18 Base address:0xc000

OR

$ip link list

1: eth0:  mtu 1500 qdisc pfifo_fast qlen 1000
   link/ether 00:0f:ea:91:04:07 brd ff:ff:ff:ff:ff:ff


i.e. current MTU value is 1500 , now we need to change it to 1300, then do the following steps


# ifconfig eth0 mtu 1300

OR

# ip link set dev eth0 mtu 1300

and verify values by ifconfig or ip link list commands.


To make the setting permanent for eth0, edit the configuration file:

/etc/sysconfig/network-scripts/ifcfg-eth0

DEVICE=eth0
BOOTPROTO=static
BROADCAST=192.168.1.255
HWADDR=00:0F:EE:70:01:02
IPADDR=192.168.1.115
NETMASK=255.255.255.0
NETWORK=192.168.1.0
MTU=1300
ONBOOT=yes
TYPE=Ethernet


That`s it , you are done with this.

Cheers !!

AJ

Comments

Post a Comment

Popular posts from this blog

HP-UX virtual Machine Cheat Sheet

HP VM Cheat Sheet  1) How to Start HP VM?  On a host a)  # vi / etc / rc.config.d / hpvmconf      # Set to 1 (0) to enable (disable) Integrity VM at boot time.              HPVM_ENABLE=1 #  / sbin / init.d / hpvm  start Note: When host is rebooted it will start all the guest by default      b)   Starting HPVM on the guest   #    hpvmstart  –P  guestname 2) How to Stop HP VM? # shutdown –hy  0    (gracefully shutdown, from guest OS)             # hpvmstop  -P guestname  ( forced shutdown from host – not recommended)   3) How to identify  Identify Host or Guest using hpvminfo command?  Examples: Using hpviminfo on a host hpvminfo   (-v, -V)(on host)   #  hpvminfo      hpvminfo : Runnin...
Read more

How to run fdisk in non-interactive mode

fdisk is a command-line utility for disk partition management.If you are going to create one or two partition then its okay to go with manual user intracetion method of fdisk. But if the partition list is a bit longer or we can say its repitative for several machines then need to seek some automation , here we go for probable two solutions for this : - Solution - I : Using below shell script #!/bin/sh sdd="/dev/sdb /dev/sdc /dev/sdd" for i in $sdd do echo "n p 1 t 8e w "|fdisk $i;pvcreate "$i"1;done n = Create new partition p = Primary partition 1 = 1st partition of primary type t = Partition type 8e = Linux LVM Note: two consicuitve blank lines between 1 and t . Solution - II : Using sfdisk Utility This tool allows you to create/change partition tables according to the disk partitioning specification read from standard input. It also allows you to export the partition table specification of a device to a file, so tha...
Read more