Comments on: Howto: Configure Linux Virtual Local Area Network (VLAN)

By: hafeez

hafeez — Thu, 18 Mar 2010 07:29:41 +0000

A working configuration example from hafeezisbad@gmail.com

Server ip : 172.27.0.10
Swtich ip / gateway ip of server : 172.27.0.100
Option domain –name servers : 172.27.0.6

Please note default vlan 172.27.0.x in this case

Switch and server need to be in default lan for communication / or else we need to trunk in case other vlan connected , we need to configure vconfig on server to communicate

For biggner I would recommend to go for the default vlan connectivity

Example :

ddns-update-style interim;
ignore client-updates;
default-lease-time 43200;
max-lease-time 43200;
authoritative;

#-----subnet mask-- broadcast-- gateway-#

option subnet-mask 255.255.255.0;
#option broadcast-address 192.168.1.1;
option routers 172.27.0.100;
option domain-name-servers 172.27.0.6;

# ----------- Server Scope and vlan1 with switches and server--------------#
subnet 172.27.0.0 netmask 255.255.255.0 {
#range 172.27.0.0 172.27.0.50;
option routers 172.27.0.1;
#option subnet-mask 255.255.255.0;
option broadcast-address 172.27.0.255;
#option domain-name-servers 172.27.0.5;
}

# ----------- clients1 Scope-vlan2-------------#
subnet 172.27.1.0 netmask 255.255.255.0 {
range 172.27.1.3 172.27.1.200;
option routers 172.27.1.1;
option subnet-mask 255.255.255.0;
option broadcast-address 172.27.1.255;
#option domain-name-servers 192.168.1.1 #
}


Save the file

Chkconfig –list dhcpd on

{ For enabling the service on all run levels }
Service dhcpd start
In case , dhcp server faild to start , check with log messages

/var/log/messages

Check for the ip helper address in layer 3 swtich , which act as dhcp-relay
Which has to be configured as 172.27.0.10

Troubleshooting Dhcp server start up error :

1) Run the Dhcp service in debug mode
2) Check the ip configuration
3) Check for syntax errors in dhcpd.conf file
4) Check for the right location of the dhcpd file
5) Ping test between the switch and server
6) Possible conflict of other dhcp server may be the issue

dhcpd in the foreground in debug mode with /usr/sbin/dhcpd -d –f

Hopefully, a DHCP server like the one we’ll be configuring will respond. Running tcpdump shows a dhcp request looks like:
17:26:02.003956 00:00:00:00:00:00 > ff:ff:ff:ff:ff:ff, ethertype IPv4 (0×0800), length 342: 0.0.0.0.68 > 255.255.255.255.67: BOOTP/DHCP, Request, length 300
You should notice DHCP running in the process (ps) list. Any problems, check syslog

Congratulations you have finally configured In easy steps

By: sayantan

sayantan — Sun, 07 Feb 2010 08:18:17 +0000

is it virtual ip?can it be used with RAC?

By: Venkat

Venkat — Sun, 17 Jan 2010 02:44:32 +0000

In the above test I have seen the statement like “Remove gateway entry from all other network config files.” How can I find the places where the gateway is configured on the system ?

Please let me know how can I test my vlan config using one single Linux PC ?

By: Arun Menon

Arun Menon — Thu, 26 Nov 2009 10:48:23 +0000

hey folks
how can i configure the vlan priority bits on the ethernet header…it wud be of gr8 help if ne1 could provide som inputs on this

regards
Arun

By: Shlomi

Shlomi — Mon, 25 May 2009 12:31:56 +0000

The line “DEVICE=ifcfg-eth0.5″, should be written as “DEVICE=eth0.5″ !!!

By: Manisha

Manisha — Mon, 20 Apr 2009 12:20:07 +0000

Can you give me the whole codes for virtual lan. and there should be browser and it should allow us to access a file from another ip address and it should allow copy, paste, save, open commands in that programm for that access file.

By: sathishenet

sathishenet — Tue, 10 Feb 2009 06:49:05 +0000

Hi All,

Very very basic question, for configuring VLAN in Linux is that necessary to have a manageable switches ??

Thanks,
Sathish

By: dekkard

dekkard — Thu, 25 Dec 2008 06:04:23 +0000

very nice! 2 minutes & vlans are set
thanx

By: siva

siva — Fri, 14 Nov 2008 08:33:12 +0000

Hey folks,

I have a couple of questions:

1.If i want to copy a file from my windows desktop to my linux (RHEL 4.0) virtual machine, how should i do it?

2.How can i assign ip address to my virtual machine?

Thanks
NSiva

By: D

Fri, 26 Sep 2008 17:49:38 +0000

It worked

By: shirish

shirish — Thu, 17 Jul 2008 09:30:05 +0000

very Helpful

By: after reading,there are some question

after reading,there are some question — Fri, 20 Jun 2008 21:46:36 +0000

Ye,after reading this topic,I learn a lot.So first,say thanks everyone.
Back to this topic,I have a question.
At say of topic owner,”an Ethernet header extension that enlarges the header from 14 to 18 bytes”,what means? I capture a frame. A Ethernet header contains destination,source,type fields.(I use adsl).And en-largeing above means add a field at Ethernet header,or add one in other place?
My Goal is building a experiment environment for network communication. It will be a complex one.It contains hundreds nodes with multiple topology structures.
Could someone give me a hand?And is vlan OK for it?If not,which can?

By: ubaid

ubaid — Wed, 11 Jun 2008 20:22:02 +0000

i have xp in my system but i wanna install ubundu Linux on it by virtual machine but it running till when it display one error after that it need additional virtual machine it cant be go ahead give me salvations how it ll be install on xp plz

By: Bincy

Bincy — Wed, 19 Mar 2008 08:35:34 +0000

I have configured valn in two linux machines with vlan id 4. Ping is working between the virtual interfaces but the ping packets have no tag attached.

I anyone have some idea please share..

Thanks

By: Gagan

Gagan — Thu, 28 Feb 2008 14:36:25 +0000

Hi,

is there any way to find out that whether systems are connected under physical or virtual LAN’s?

please tell me know …

By: csmith

csmith — Fri, 11 Jan 2008 23:21:18 +0000

“one dhcp server using multiple vlan’s”
I’d presume you change /etc/sysconfig/dhcpd file
specify which virtual adaptors you want the dhcpd service to runon “eth0 eth1 eth1.10″ would be ethernet if 0, 1, and vlan 10 on eth1. Thats where I’d start. Though you may have a lot of….er..fun if you dont have an injection of which vlan is making the request they’ll all get the same pool. (option 82 enabled devices)

By: fsmendoza

fsmendoza — Thu, 29 Nov 2007 15:47:06 +0000

Hi everyone,

is it possible to do “one dhcp server using multiple vlan’s”? does anyone successfully do this? Please let us know howto.

Thank you.

By: Vivek

Vivek — Sat, 13 Oct 2007 12:53:36 +0000

Sir,
I have followed the steps mentioned in “How to configure VLAN in LINUX”. I am using fedora 7.
although I am able to configure VLAN but I am not able to ping it to my client computer and vice versa.
If I don’t configure vlan then everything works fine on this interface i.e. eth1.
Kindly provide me with some solution.

By: George

George — Thu, 26 Jul 2007 19:20:34 +0000

I was looking for a site to explain this in plain english and i found it! thank god! :)

a few questions:
1st, how can i configure the system so everything takes a dhcp address once the system initializes? Should i configure a dhcp server so that when a computer starts it will send a DHCP request? How can i setup a dhcp server to give different ip address ranges to different VLANS? If i am trying to access a resource from within a vlan, will i need a dns server internally to translate the domain name (if used) to the different ip addresses a device will have?

thanks!

By: Eric Arnaud

Eric Arnaud — Tue, 03 Jul 2007 03:24:45 +0000

Here is my problem.

Office 1 has 3 networks (VLAN port-based)
Office 2 is 500′ away with a switch in the middle and only one cat5 cable

I’m trying to find a way to convert port-based vlan to TAG (IEEE 802.1Q or similar )

Ex: On a x86 with linux or wrt54g

Port1 = Lan #1 => Tag #1 on port4
Port2 = Lan #2 => Tag #1 on port4
Port3 = Lan #3 => Tag #1 on port4

port4 got to the other wrt54g on port4

on the other device

port4 (tag #1) => Port1
port4 (tag #2) => Port2
port4 (tag #3) => Port3

So basicly is how to tag a incomming packet on port x and untag once on the other side.
The routing part is almost simple.

Eric