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
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.
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.
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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.
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
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 :)
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