Implement Cisco Cataylst 6500 switches at layer 3

Have a question or want to start a discussion? Post it! No Registration Necessary.  Now with pictures!

Threaded View
Wouls anyone be kind enough to tell me - or point me in the right
direction, of what's involved with replacing a Cisco Catalyst 5500
switched network (about 20 switches) running layer 2 (Catos), with a
Route switch module, in place of a layer 3 network using Cisco catalyst
6509 running IOS.

I have been told that i have to change all of my vlans and ip
addressing scheme to facilitate the migration but this seems quite an
enormous task. Many Thanks


Re: Implement Cisco Cataylst 6500 switches at layer 3
Quoted text here. Click to load it

you can run a 6509 in 2 ways:

hybrid mode has L2 VLANs set up using CatOS, IOS on the MSFC as an internal
logical router. This is similar to a Cat 5500 with an RSM.

IOS mode uses IOS config for everything - VLANs become switchport
definitions etc
 - so CatOS "stuff" needs to be translated and merged with the IOS config.

many configs can use either option, but some features require you to use a
specific setup - eg if you use DFC cards to improve L3 thruput then you have
to use IOS only mode.

generally new L2 features appear in CatOS images 1st, so choosing which way
to go can be complicated and mean you need to compare feature sets etc.
Quoted text here. Click to load it

Address plan should not need to change (although migration might mean it is
easier to change things if you need old and new switches in place at the
same time).
VLAN numbering can stay the same, but the config will be different.
Quoted text here. Click to load it
--
Regards

stephen_hope@xyzworld.com - replace xyz with ntl



Re: Implement Cisco Cataylst 6500 switches at layer 3
Many Thanks for your post Stephen. Does that mean that if i retain the
existing vlan set-up then there will be no issues routing traffic using
layer 3 to a particular vlan which may be split over different
locations?

stephen wrote:
Quoted text here. Click to load it


Re: Implement Cisco Cataylst 6500 switches at layer 3
Quoted text here. Click to load it

standard cop out - that depends :)

but you should be able to make a Cat6k do anything with VLANs that a 5500
could do...

however - when you have to alter stuff anyway it is a good idea to see if
the design still makes sense
 - your old 5500 has serious thruput limits (eg with GigE ports) that the
Cat isnt going to replicate, so changes may be a good idea.
Quoted text here. Click to load it
catalyst
internal
config.
a
have
way
is
--
Regards

stephen_hope@xyzworld.com - replace xyz with ntl



Re: Implement Cisco Cataylst 6500 switches at layer 3
On Mon, 11 Dec 2006 22:53:48 +0000, stephen wrote:

Quoted text here. Click to load it



my 2 cents - when you go to plug in the new switches into the existing
switch fabric, make sure the new  ones are in VTP CLIENT mode


Re: Implement Cisco Cataylst 6500 switches at layer 3
Quoted text here. Click to load it
5500
if
the
a
use
you
which
etc.
an
it
the

my 2p (different currency) - whoever invented VTP should be stood against a
wall and shot -
or at least his "mate" who made it on by default...

If it is working properly, the existing 5500 is probably the master, so you
need to think about what you want before plugging it all together

other prep:
diagrams.
pull all configs files and store somewhere.
check running configs match stored configs (i think this isnt an issue with
CatOS - but that is a long time ago).
more diagrams for what you are trying to make the new design look like.
migration and back out plan (in case the migrate goes wrong - roughly 30 to
50% of big changes seem to take a couple of trys, or at least have a few
remaining issues still to solve after the change).
panic plan (for backout after you thought it was all working, but the users
come to work and tell you differently).

its a good idea to have the old and new core switches in your comms room
during the transition so you can back out easily without moving hardware -
and that way you can check the Cat6k powers up and all the cards work before
you hook it up.

finally - silly stuff
 - enough power & aircon in the comms room?
- lots of spare patch leads?
- new fibre SFPs use different connectors?

all of those got me at 1 time or another :)

If you want to pick Cisco brains then, the latest Cisco best practice guides
are at
www.cisco.com/go/srnd

Quoted text here. Click to load it
--
Regards

stephen_hope@xyzworld.com - replace xyz with ntl



Re: Implement Cisco Cataylst 6500 switches at layer 3
Many thanks for all your advice Stephen.

stephen wrote:
Quoted text here. Click to load it


Site Timeline