VLAN configuration

A very convenient support for software VLANs (Virtual Local Area Network) IEEE 802.1Q is provided by PLD rc-scripts. Software VLANs are available both in 2.4 kernels, and 2.2 kernels from PLD.

To be able to use VLAN, an extra software is necessary (it is provided by vlan rpm package). Then, all we need is setting up proper VLAN interface description.

	    DEVICE="eth0.4"
	    ONBOOT="yes"
	    BOOTPROTO="none"
	    IPADDR="192.168.0.13"
	    PREFIX="24"

Example VLAN interface file: /etc/sysconfig/interfaces/ifcfg-eth0.4

Then, bringing up interface eth0 automatically creates VLAN on interface eth0 using address provided in IPADDR variable. The digit 4 in DEVICE tells that device should be in VLAN 4.

Appending ".4" to the file name does not have any special meaning, here it has been done just to distinguish somehow this file from file ifcfg-eth0 containing main description of interface eth0 that must be also present in the directory.

Hardware VLAN

Setting up

PLD contains software to support hardware VLAN available in Intel(R) PRO/100 adapters. However, using that is a bit more complicated that setting up software VLANs described in previous section.

First, some extra software is necessary: kernel-net-e100, kernel-net-ians and ians. Number of possible VLANs is limited to 64, though they can be numbered from 1 to 4096.

Package kernel-net-e100 provides kernel module e100 that is replacement for standard kernel module eepro100. Thus in /etc/modules.conf we replace (assuming we have eth0 and eth1 interfaces):

	      alias eth0 eepro100
	      alias eth1 eepro100

with

	      alias eth0 e100
	      alias eth1 e100

It is not possible to simultaneously use eepro100 and e100 modules because intel module, once loaded, immediately searches for all installed cards.

Next step is to turn down all interfaces based on Intel adapters if they are running. That can be done be stopping network subsystem that (as described in ), or by stopping particular interfaces (that can be found in ). Also remove old module, if it is still present (rmmod eepro100).

Now the VLANs must be configured. Here is the real-life example:

	      ianscfg -a -t ve1 -M NONE -V
	      ianscfg -a -t ve1 -m eth1 -p none
	      ianscfg -a -t ve1 -v eth1.40 -i 40
	      ianscfg -a -t ve1 -v eth1.43 -i 43
	      ianscfg -a -t ve1 -v eth1.44 -i 44
	      ianscfg -a -t ve1 -v eth1.45 -i 45
	      ianscfg -a -t ve1 -v eth1.46 -i 46
	      ianscfg -a -t ve1 -v eth1.47 -i 47
	      ianscfg -a -t ve1 -v eth1.48 -i 48
	      ianscfg -c ve1

This sequence creates 7 VLANs (40, 43, 44, 45, 46, 47, 48) on eth1 adapter. Interfaces themselves are configured in standard way, (like in ), by creating description file in /etc/sysconfig/interfaces/. E.g. for eth1.40 it could be defined in file /etc/sysconfig/interfaces/ifcfg-eth1.40 in following way:

	    DEVICE="eth1.40"
	    ONBOOT="yes"
	    BOOTPROTO="none"
	    IPADDR="192.168.0.13"
	    PREFIX="24"

Now it's enough to bring all interfaces up. This can be accomplished with the following procedure:

```
ianscfg -a -t ve1 -M NONE -V
```
Create "team" named ve1 without any team-mode (teams are discussed )
```
ianscfg -a -t ve1 -m eth1 -p none
```
Add to team ve1 interface eth1 without any priority
```
ianscfg -a -t ve1 -v eth1.40 -i 40
```
Add virtual interface eth1.40 working on VLAN 40 to team.
```
ianscfg -c ve1
```
"Commit" team ve1 (make it active).

In this solution, system does not know anything about VLANs because they are supported on hardware level. The disadvantage of this solution is that VLANs must be configured first, before interfaces could be brought up. Bringing interfaces down must be performed in reverse order. Thus, in our example:

	    ianscfg -d -v eth1.40
	    ianscfg -d -v eth1.43
	    ianscfg -d -v eth1.44
	    ianscfg -d -v eth1.45
	    ianscfg -d -v eth1.46
	    ianscfg -d -v eth1.47
	    ianscfg -d -v eth1.48
	    ianscfg -d -m eth1
	    ianscfg -d -t ve1

When interfaces are named like in the example, the vlan package must not be installed, otherwise rc-scripts would attempt to additionally set up software VLANs.

Aggregation of network cards

Using e100 modules, ians and ianscfg it is possible to make use of so-called aggregation of network cards i.e. multiple network adapters can be used as one device.

Intel cards have 3 modes of team-work:

Adapter Fault Tolerance (AFT)
Default mode. Only one card is working (called primary), while second card waits. If primary card dies, second card replaces it.

Adaptive Load Balancing (ALB)
Allows for sharing the load among 2-8 network cards, but only primary receives and transmits packets.

Link Aggregation (FEC*/LA/802.3ad or GEC*/LA/802.3ad)

FEC*/LA/802.3ad (Cisco*'s Fast EtherChannel* Technology (FEC)/Intel Link Aggregation or IEEE 802.3ad Link Aggregation) allows for collective work of 2-8 adapters in receiving/transmitting packets. All cards must work with the same speed and the same duplex. Aggregation must be supported by switch and spanning tree must be enabled.

GEC*/LA/802.3ad is a similar mode for Gigabit. Module e1000 should be used instead of e100.

Example:

	    ianscfg -a -t ve0 -M ALB
	    ianscfg -a -t ve0 -m eth0 -p primary
	    ianscfg -a -t ve0 -m eth1 -p secondary
	    ianscfg -c ve0

Additionally, the team can handle VLANs on team.