Monday, May 28, 2012

Kompella L2 BGP Based VPN RFC Status Change

Kompella L2 BGP Based VPN RFC Status Change

Abstract from RFP 

"Layer 2 Virtual Private Networks (L2VPNs) based on Frame Relay or ATM circuits have been around a long time; more recently, Ethernet VPNs, including Virtual Private LAN Service, have become popular.

Traditional L2VPNs often required a separate Service Provider infrastructure for each type and yet another for the Internet and IP VPNs.  In addition, L2VPN provisioning was cumbersome.  This document presents a new approach to the problem of offering L2VPN services where the L2VPN customer's experience is virtually identical to that offered by traditional L2VPNs, but such that a Service Provider can maintain a single network for L2VPNs, IP VPNs, and the Internet, as well as a common provisioning methodology for all services."

Wednesday, May 23, 2012

Building a Free Network Emulator, Vyatta

Creating a Packet-Loss / Delay Emulator Using Vyatta

If you need a network emulator to create a configurable amount of packet-loss, packet-corruption, packet-reorder, delay, bandwidth,  or etc, you could use a free routing software called Vyatta with a PC which has at least 2 NIC. Vyatta installation is out of the topic, but you could find how to configure a vyatta installation to create your own network emulator. I used this emulator for testing purpopes to understand the effects of packet loss on video streaming, and i hope you would find it useful too. For whom experienced Junos, it will be very easy to use this system.

What is Vyatta

Vyatta is an open source routing software which is developed by the Vyatta company created in 2005. It uses a routing engine called XORP created in 2002. Except MPLS features it has nearly all the features that is expected from a CE device. If you ever use Junos, you will see that using Vyatta is like using Junos. For additional information about Vyatta take a look at the links below:    vyatta live cd & esx images      vyatta--cisco commands & case studies

Vyatta Configuration

Assuming that you already installed Vyatta on a PC that has 2 NIC, all you need to do is to configure the Vyatta to work transparently (inline).  The main idea is to bridge (local connect) any vlan that should pass transparently over your network emulator.

For a network emulator which vlan 100 and native vlan should pass through, the configuration should look like:
edit traffic-policy network-emulator drop_test
  set drop packet-loss 5
  set network-delay 100
set interfaces bridge br0
set interfaces bridge br1
edit interfaces ethernet eth0
  set bridge-group bridge br0
edit interfaces ethernet eth1
  set bridge-group bridge br0
edit interfaces ethernet eth0 vif 100
 set bridge-group bridge br1 
edit interfaces ethernet eth1 vif 100
 set bridge-group bridge br1 

edit interfaces ethernet eth0 vif 100
  set traffic-policy out ercin_drop
network policy  creation
create Bridge interface 0
create Bridge interface 1
include Ethernet0 native vlan to bridge group 0
include Ethernet1 native vlan to bridge group 0
include Ethernet0  vlan100 to bridge group 1
include Ethernet1  vlan100 to bridge group 1
configuring network policy named ercin_drop to under eth0 vlan 100 in outbound direction
All changes applied with a commit
if you install vyatta on a hdd, you could save the config.

For additional configuration information, you may have a look at the QOS documents of Vyatta. 


With Vyatta you could apply packet delay, loss, reorder etc. for any vlan in any direction. Most of the free solutions does not have a vlan flexibility. If you have a Pc with at least 2 ethernet interaces, you could easily have a basic network emulator. You could even use this sytem for fiber ethernet with a NIC that has SFP capability, what important is that if Vyatta automatically detects your NIC otherwise you have to struggle with linux. 
You may  buy Vyatta appliances also to use it as a network emulator also. In Turkey there is no distributor of Vyatta, but may be you could find in your country. 

If you are interested in free network emulator solutions, you should have a look at Wanem solution too. 

Monday, May 21, 2012

Juniper Bootable Compact Flash

Creating a Bootable Compact Flash for Juniper Devices

If you want to create a boot disk to reconfigure a juniper router from scratch, you may want to create a boot disk. Sometimes it is easier to upgrade junos by formatting and reloading the old config if you are upgrading from an old release which requires a step by step upgrade through major releases.
There are various ways to create a CF card, but the easiest way i found to create CF card is:
Select the CF card in program and write the junos install-media image to CF as raw.

If you reboot a Juniper with a bootable CF card created as explained, system will be booted from CF card and will ask you if you want to reconfigure your router from scratch.

Configuring Jumbo MTU in Windows or Linux

If you are in to networking area, you might know that jumbo frames are Ethernet frames with more than 1500 bytes of payload, and if you ever try to capture these packets with a standard configured operating system you will see that these packets would not seem to come to your NIC card. this is because the OS are not configured for Jumbo MTU's. If your NIC supports jumbo frames,  you can configure your OS as explained below:

 Microsoft Windows

  1. In Microsoft Windows, right-click the Network Adapter in Network Connections, and then click Properties.
  2. Click the Configure button and then the General tab. Jumbo MTU is set at 1500 bytes by default (disabled). To increase the size of the received frames, select a value that is available by NIC driver.

Linux (Debian/Ubuntu)


The MTU of an interface can be changed temporarily using the mtu option of the ifconfig command:

ifconfig eth0 mtu 9000

The new MTU will not persist beyond a reboot.


If the interface has (or can be given) a static configuration in /etc/network/interfaces then its MTU can be persistently altered by adding an mtu option to the relevant iface stanza, for example:

auto eth0
iface eth0 inet static
 mtu 9000

This method does not work when using other configuration methods such as dhcp.

You can activate the new MTU can by taking the interface down using ifdown then bringing it back up using ifup:
ifdown eth0
ifup eth0
Alternatively you could reboot the machine.

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