From: Ben Holko (ben.holko@datacom.com.au)
Date: Sun Nov 18 2007 - 03:54:37 ART
I have done pretty much an entire lab now on this infrastructure, and it's all working perfectly as expected.
The only drawback to using a trunk out of the Dynamips server as opposed to a physical NIC per logical interface, is that you cannot due 802.1q subinterfaces on your logical router interfaces, because they would be tagging which would then be replaced by the OS tag config.
from memory, the IE topology only uses router subinterfaces on R5 and R6, so you could use a dedicated NIC port on the server for these router interfaces (connected straight into 3550) and then have full functionality, otherwise practice those things in other labs using Dynamips switches.
I'm using a 2511-RJ for console access to the switches.
Ben
________________________________
From: nobody@groupstudy.com on behalf of Ben Holko
Sent: Fri 16/11/2007 11:34 AM
To: Scott Vermillion; ccielab@groupstudy.com
Subject: RE: Dynamips - real ethernet - why use USB?
Well I have got this up and running, after some pain (on the Linux end).
I have a 2nd NIC in my Linux machine (eth1) which I create VLAN's on
with vconfig ('vconfig add eth1 101', 101 being the vlan number). The
catch was, it's a Broadcom NIC, which strips the .1q tag off in
hardware. After much searching, I discovered that using the Broadcom
diagnostic dos utility this "feature" can be disabled, and the tags are
subsequently maintained.
So out of eth1 I have 1 cable going into a Cat 2900xl, port number 1,
which is configured as a dot1q trunk. I then take one cable on a
dedicated switch port per logical router interface out of the 2900 (2900
port configured as an access port with the appropriate Linux VLAN
number) and directly into my 4 x 3550's.
On the Linux end you create one VLAN sub-interface per logical router
interface. For example, if you have 3 routers with 2 ethernet's each,
you need 6 sub-interfaces and subsequently 6 vlan's, and subsequently 6
cables going from the 2900xl into the 3550's. These 6 vlans should be
numbered differently to any VLAN's you are going to use in your lab
topology, for the sake of easy troubleshooting and non-confusion.
Basically this architecture is exactly the same logical premise as the
Mac Mini and the USB approach, but instead of multiple USB/Ethernet
adapters, you need 1 spare 802.1q capable NIC in your Dynamips machine,
and a dedicated 802.1q capable switch. A 2900xl is cheaper than 10+
USB/Ethernet adapters :)
In your Dynagen config, instead of mapping the router's ethernet's to a
USB NIC, you map them to the VLAN sub-interfaces, aka "eth1.101" for
example. As with all Dynamips real-ethernet connectivity, you need to
run Dynamips as root to be able to map raw to Ethernet.
I have done some testing and it all seems to work fine, will do a full
lab config over the weekend and let you know how it goes.
Ben
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Scott Vermillion
Sent: Friday, 9 November 2007 4:13 AM
To: Ben Holko; ccielab@groupstudy.com
Subject: RE: Dynamips - real ethernet - why use USB?
Hey Ben,
Well, thanks much for your kind remarks. I forward all credit for the
USB
concept to the IE Brians. They're the true genius behind that little
gem
(I'm just the sometimes reporter).
Your concept is interesting, to say the least. I'm not a linux guy, so
I
guess I have to sit this one out. You may wish to float this to the
Hacki
forum. Both the developer of Dynamips and Dynagen are regular
contributors
there, so you're likely to get a good response to this proposal.
http://7200emu.hacki.at/index.php Do let us know what you find out
either
via the forum or your own experimentation!
Regards,
Scott
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
Ben
Holko
Sent: Thursday, November 08, 2007 5:07 AM
To: ccielab@groupstudy.com
Subject: Dynamips - real ethernet - why use USB?
Hey all,
There have been several informative posts and topics (thanks Scott V!)
on using things such as a MAC Mini and USB Ethernet to link your
Dynamips routers to REAL switches - and I suddenly got to thinking, why
use USB at all?
Why cant we run up 802.1Q sub interfaces in Linux, run a trunk into a L2
802.1Q switch (say a 2950), and then connect out of the 2950 into our
REAL 4 x 3550/3560 with one cable per logical router interface (say one
vlan in the 3000 range for each router interface)?
It's basically the same premise as using the 16 x USB Ethernet adapters,
but using an extra switch and 802.1Q subinterfaces on Linux instead, to
break out into one physical cable per Dynamips router interface.
Can you configure Dynamips to map each router interface to a separate
logical Linux 802.1Q interface? I will be trying it when I get back from
interstate next week.
The reason I got to thinking this, is my Linux Dynamips box (a Dell 2650
PowerEdge) is not liking its USB controller, and it has a second
10/100/1000 Broadcom NIC sitting idle - the 5th switch required to
perform physical interface break-out could be anything that supports
802.1Q, doesn't even have to be a Cisco, which would potentially make it
even cheaper than the USB approach!
Any thoughts?
Ben
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