Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Set host default gateway in C program.
Top Forums Programming Set host default gateway in C program. Post 302446007 by Corona688 on Tuesday 17th of August 2010 11:16:28 AM
Old 08-17-2010
Usually, even in C, you'd just use the commandline tools. This will make for a much more portable program. Otherwise, the ioctl's will vary wildly across systems. I'm not sure it even uses ioctl to do so in linux at all, for that matter -- it might be netlink these days, which is a lot more impenetrable.

Suppose you have IP 192.168.1.2, mask 255.255.255.0, DNS server 192.168.1.1, gateway 192.168.1.1. You can change the IP and netmask of an interface with the ifconfig tool, like so:

Code:
/sbin/ifconfig eth0 ip 192.168.1.2 netmask 255.255.255.0

You can alter DNS parameters by managing the list of hosts in /etc/resolv.conf .
Code:
echo nameserver 192.168.1.1 > /etc/resolv.conf

And gateways are done through the route command.
Code:
/sbin/route add default gateway 192.168.1.1 eth0

If you really insist on doing it with ioctl, try runing strace ifconfig eth0 ip 192.168.1.2 netmask 255.255.255.0 to see what raw ioctl it uses; that's how I found things like the serial port ioctls...
Last edited by Corona688; 08-17-2010 at 12:23 PM.. Reason: fixed mutation
 

10 More Discussions You Might Find Interesting

1. Shell Programming and Scripting

How to end a host concurrent program in WARNING?

Hi, I want to end a host (shell script based) concurrent program in WARNING. Is it possible? Tried out a few things but it just either ends in NORMAL or ERROR. :confused: Any ideas/inputs would be appreciated. Thanks, coolblue_3 (2 Replies)
Discussion started by: coolblue_3
2 Replies

2. UNIX and Linux Applications

set mysql password with host parameter

hi, linux gurus... i'm trying to write a script in ksh called ResetPass that allows a user to change mysql passwords. the script accepts user, password and host like this: ResetPass <user> <password> <host>. here's the code: ***************************************************** mysql... (1 Reply)
Discussion started by: ankimo
1 Replies

3. Shell Programming and Scripting

Kill shell script when host program not running/disk unmounted

I have my Mac OS X program executing a shell script (a script that copies files to a drive). I want to make it so that the shell script automatically kills itself if it finds that the host .app is not running OR kill itself if the drive that it is copying files to has been unmounted. Right now what... (2 Replies)
Discussion started by: pcwiz
2 Replies

4. Programming

How to read max stack size -Xss that is set/default for a java program?

I need to know what is the maximum stack size i.e. -Xss my java program is running with. Is there a way to find that out from inside my java program code and outside of it. What i am looking for is to read whatever the current set max limit -Xss (stack sie) is for a particular JVM(not... (3 Replies)
Discussion started by: mohtashims
3 Replies

5. Solaris

How to set gateway address to a particular interface?

How to set gateway address to a particular interface? waht are the files need to update to make it permanent? (2 Replies)
Discussion started by: Naveen.6025
2 Replies

6. Shell Programming and Scripting

Set variable to path that does not exist on local host

Can anyone suggest a workaround zone_5.org='/qaz/qwe/path/tns.osn' output /home/bingo/XXX_script.sh: line 180: zone_5.org=/qaz/qwe/path/tns.osn: no parent The path does not exist on the local machine, the allocation used to work till the server was upgraded. Red Hat Enterprise Linux... (2 Replies)
Discussion started by: squrcles
2 Replies

7. Red Hat

Create an unconfigured VMware host from a template that is set to do firstboot --reconfig

I have an Oracle Linux 7.1 vsphere host built. It's be preconfigured with our security configurations. What I would like to do is unconfigure this host. Then set the host to do firstboot --reconfigure. how do I do that using /etc/sysconfig/firstboot? I've tried setting ... (10 Replies)
Discussion started by: os2mac
10 Replies

8. Shell Programming and Scripting

How to end a host concurrent program in WARNING status?

Hi All, I have a requirement to make a oracle concurrent program end with warning based on a given condition. If the condition is true, the concurrent program should end with completed warning status. The host program I am using is a shell script that checks if a file exists. ... (2 Replies)
Discussion started by: megha2525
2 Replies

9. Red Hat

Set new gateway for route to internet

Hi all, i have a rhel 6.2 with a default gateway. This server is an Intranet office with no internet access. DNS are already configured and it's possible to resolve my target. My goal is to link my application (apache forward) only to http://mytarget.yyy through a new gateway (That does... (0 Replies)
Discussion started by: kamose
0 Replies

10. UNIX for Beginners Questions & Answers

Inconsistency between RedHat 6.5 global gateway and single gateway leads to loss of default gateway

Dear friends I use RedHat 6.5, which sets the gateway in the configuration file / etc / sysconfig / network as GATEWAY = 192.168.1.26, and the gateway in the configuration file / etc / sysconfig / network-scripts / ifcfg-eth11 as GATEWAY = 192.168.1.256. The two gateways are different.... (6 Replies)
Discussion started by: tanpeng
6 Replies

LEARN ABOUT DEBIAN

vlan-interfaces

VLAN-INTERFACES(5)						   File formats 						VLAN-INTERFACES(5)

NAME

       /etc/network/interfaces (vlan) - vlan extensions for the interfaces(5) file format

DESCRIPTION

       /etc/network/interfaces	contains  network  interface  configuration  information  for  the  ifup(8)  and ifdown(8) commands.  This manpage
       describes the vlan extensions to the standard interfaces(5) file format.

       Primary extensions exist to make and destroy vlan interfaces, secondary extensions exist for ipv4 interface manipulation which  are  gener-
       ally needed when using (a lot of) vlans.

VLAN CREATION

       Vlan  interface	definitions  exist  of the vlan interface name, and an optional 'raw-device' parameter.  Vlan interfaces are numbered 1 to
       4095.  You have the option to have interface names zero-padded to 4 numbers, or just the plain digits without leading zero.  The  following
       example shows four ways to create a vlan with id 1 on interface eth0.  They all result in different names.

	iface eth0.1 inet static
	    address 192.168.1.1
	    netmask 255.255.255.0

	iface vlan1 inet static
	    vlan-raw-device eth0
	    address 192.168.1.1
	    netmask 255.255.255.0

	iface eth0.0001 inet static
	    address 192.168.1.1
	    netmask 255.255.255.0

	iface vlan0001 inet static
	    vlan-raw-device eth0
	    address 192.168.1.1
	    netmask 255.255.255.0

	# We don't have br support out of the box
	iface br0.2 inet static
	    vlan-raw-device br0
	    address 192.168.1.1
	    netmask 255.255.255.0

	# Aliases are ignored
	iface br0.2:1 inet static
	    address 192.168.1.1
	    netmask 255.255.255.255

EXTRA IFACE OPTIONS

       Usually someone who uses vlans also wants to do some other manipulations with the ip stack or interface.

       vlan-raw-device devicename
	      Indicates the device to create the vlan on.  This is ignored when the devicename is part of the vlan interface name.

       ip-proxy-arp 0|1
	      Turn proxy-arp off or on for this specific interface.  This also works on plain ethernet like devices.

       ip-rp-filter 0|1|2
	      Set the return path filter for this specific interface.  This also works on plain ethernet like devices.

       hw-mac-address mac-address
	      This sets the mac address of the interface before bringing it up.  This works on any device that allows setting the hardware address
	      with the ip command.

AUTHOR

       This manpage was adapted from interfaces(5) by Ard van Breemen <ard@kwaak.net>

SEE ALSO

       vconfig(8) interfaces(5)

vlan								 September 30 2007						VLAN-INTERFACES(5)
All times are GMT -4. The time now is 11:29 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy