Basics: Switches, VirtualBox and GNS3

Getting your physical switches to talk to virtual machines and GNS3 routers.

Physical PC to Virtual PC

How I converted my old physical desktop running XP to a Virtual Machine…

Duplex Mismatch

I’ve had this happen several times, I connect a 3725 to a 3640 using slot 0 (f0/0) and bam, duplex mismatch… no matter how many times I configure “duplex full” on each interface, one of them goes back to half-duplex. 

 

BGP choosing longer AS_Path as preferred route...

The following network might look familiar if you’re going through the 642-902 book; and, if you are following the reading by configuring the examples in GNS3, you will find an omission which isn’t discussed until several sections later (that discussion does not clarify the problem as there is no mention of a problem with the example… but there is problem!)

no parser cache ...

I was configuring bgp earlier today and incorrectly entered an ip address in the neighbor statement… something like:

Redistribution with a Route Map

(or, how I forgot to remember to change the loopback network type and will remember to never forget in the future...)

The goal is to redistribute OSPF into EIGRP while preventing routes L1, L2, L4,& L6 in OSPF 50 Area 3 from being redistributed (these routes are configured as loopbacks on R3); All EIGRP routes are to be redistributed into OSPF.

Configuring SuperPuTTY for GNS3

Notes:

Host…………………….Win7 Pro

GNS3 version………….0.8.1

Putty.exe version………beta 0.62[ http://www.chiark.greenend.org.uk/~sgtatham/putty/download.html ]

–note, you must have putty installed (i.e. the putty.exe file)

SuperPuTTY version….v1.2.0.11[ http://code.google.com/p/superputty/downloads/list ]

OSPF router is not using the adjacent neighbors’ highest loopback as Neighbor ID

AKA, configuring the loopback after creating the OSPF process...

Setting key chain time-based authentication for EIGRP in GNS3…

Notes:

My lifetime config on all routers:

R(config-keychain-key)# accept-lifetime 06:00:00 May 9 2012 infinite

R(config-keychain-key)# send-lifetime 06:00:00 May 9 2012 infinite

• GNS3 0.8.1
• VirtualBox 4.1.6
• Still using the same topology from ntp server post:
• Global config command clock save interval hours crashed the routers... so I'm not using this as a soloution.

Setting a VirtualBox XP Machine as an NTP Server in GNS3

The following is how I set an xp vm to act as an ntp authoritative time server for a LAN within GNS3. This took some time and yes, I know that setting one of the routers as the ntp server is much easier to do… but where’s the fun in that? This is just something I was fooling around with and how I got it to work.