Since then things have beenworking very well. No more layer 1 issues troubleshooting all the time

Configuration steps

Install the  vconfig package used for managing vlans. 8021q support can be loaded as a module. So no need for a kernel recompile.

My config

On my Ubuntu 9.04 x64

modprobe 8021q
vconfig set_name_type VLAN_PLUS_VID

vconfig add eth1 101
vconfig set_flag vlan0101 1 0
ifconfig vlan0101 inet 0.0.0.0  up

vconfig add eth1 102
vconfig set_flag vlan0102 1 0
ifconfig vlan0102 inet 0.0.0.0  up

vconfig add eth1 103
vconfig set_flag vlan0103 1 0
ifconfig vlan0103 inet 0.0.0.0  up

vconfig add eth1 104
vconfig set_flag vlan0104 1 0
ifconfig vlan0104 inet 0.0.0.0  up

vconfig add eth1 105
vconfig set_flag vlan0105 1 0
ifconfig vlan0105 inet 0.0.0.0  up

vconfig add eth1 106
vconfig set_flag vlan0106 1 0
ifconfig vlan0106 inet 0.0.0.0  up

vconfig add eth1 107
vconfig set_flag vlan0107 1 0
ifconfig vlan0107 inet 0.0.0.0  up

vconfig add eth1 108
vconfig set_flag vlan0108 1 0
ifconfig vlan0108 inet 0.0.0.0  up

vconfig add eth1 109
vconfig set_flag vlan0109 1 0
ifconfig vlan0109 inet 0.0.0.0  up

vconfig add eth1 110
vconfig set_flag vlan0110 1 0
ifconfig vlan0110 inet 0.0.0.0  up

vconfig add eth1 111
vconfig set_flag vlan0111 1 0
ifconfig vlan0111 inet 0.0.0.0  up

vconfig add eth1 112
vconfig set_flag vlan0112 1 0
ifconfig vlan0112 inet 0.0.0.0  up

I have one instance of dynamips per router

To start the dynamips instances

sudo dynamips -H 7200 &
sudo dynamips -H 7201 &
sudo dynamips -H 7202 &
sudo dynamips -H 7203 &
sudo dynamips -H 7204 &
sudo dynamips -H 7205 &
sudo dynamips -H 7206 &
sudo dynamips -H 7207 &
sudo dynamips -H 7208 &
sudo dynamips -H 7209 &
To create a loopback for use with terminal server

modprobe tun
tunctl
ifconfig tap0 169.1.1.1 netmask 255.255.255.0 up

Starting dynagen

dynagen /opt/dynamips/initial_config/Rack1/rip/ie_rns_7200vlan.txt

http://higmc.wordpress.com/dynamips-config/

Useful links

http://onvox.net/linux/how-to-enable-8021q-vlan-tagging-in-ubuntu

http://zephon.ccieblog.com/2009/05/17/final-dynamips-setup/

http://7200emu.hacki.at/viewtopic.php?t=7540

http://enotepad.wordpress.com/category/dynamips/

My desktop with Ubuntu 9.04

I have spend a couple  of frustating hours troubleshooting my dynmips links with real switch links. Even though I have the simpler scenario of 12 port directly connecting to switches , it can be confusing when things choose to work at times and stop working later.

Looks like I have been able to isolate this to two interfaces on my ZYNX quad card. Its probably just the age of the card taking its toll.

I am waiting for a pair or Adaptec Quad cards to swap this out.

I have this cabled for the interetworks expert topology.

3x  4 port zynx cards

2×3550

2×3560

I wanted to start off with OSPF as I was not too happy with it before i did my CCIE-W . However troubleshooting all of the L2 topology with the cabling problems seemed too much.

So i scaled back and started off with switching yesterday and did a few labs

I will post pictures and more details as this progresses.

Chao

I like Linux but am still most at ease with my Winxp as my desktop

I already have 2 x 3550 and 2 x 3560 switches for setting up a  dynamips + real switches topology

I am looking at a quad core setup with 64bit Linux for under $500

I just got a q9550 intel quad for 159+ taxes at Microcenter. Still need to order other parts though.

Hope to have this setup by this weekend

I also created my own olive lab in the process so that I could get some hands on experience.

Once i am done with this it will be back to lab prep full steam

I took the CCIE R&S written and passed.  That was a big releif after close to 6 months of Studying.

So taking a two week break from Cisco studies to do a free JNCIA exam.

After all a little multi vendor exposure does not hurt

On to lab preparations full steam starting September.

And being lazy doesn’t exactly help

Speed /Duplex

• Sense speed using Fast Link Pulses
• If auto negotiation disabled ; can detect using electrical signals
• Duplex can be detected only by auto negotiation
• Default diplex 10/100 -Half 1000-Full

CSMA /CD

In case of collusion send jamming signal and random timer to transmit again
Hub — single collusion domain
Switches buffer packets , when multiple packets received for the same host.
NICs in half duplex use a loopback circuitry to detect collusions

Speed needs to be set before duplex can be configured on an interface

Half duplex interface statistics
Collusions –> detected during the transmission of the first 64bytes
Late collusions –> Collusions after the transmission of the first 64 bytes
Deferred frames –> Switch send frames later as it was receiving a frame

IEEE 802.3
DSAP –> Protocol Type Field
SSAP –> Protocol type to describe the upper layer protocol that created the frame
SNAP –> Subb-Network access protocol ; overcomes size limitations of DSAP

Mac Address –> 6bytes , First 3bytes OUI , last 3 assigned by vendor

Unicast -> Most significant bit in most significant byte set to 0 (8th bit in 1st byte) I/G (Individual/Group)
OUI –> Organizationally unique identifier , assigned to each vendor , 3bytes
Canonical /little endian ordering
Multicast I/G bit set to 1

U/L –> Universal/Local bit (0 –vendor assigned , 1– administratively assigned OUI)

Unicast –> Forward out of single int
Unknown unicast –>Forward out of all int except arriving
Broadcast –> Forward out of all int except arriving
Multicast –> Forward out of all int except arriving (Except if switch configured for multicast)