From: Darby Weaver (darbyweaver@yahoo.com)
Date: Sun Jun 04 2006 - 12:42:41 ART
At how many points are these networks going to meet?
1 or more?
Do they have common RFC1918 Address Classes?
Which traffic needs to get from Company A to Company
B?
Are you planning to change the IP Scheme of one of
both companies?
The company I work for has been bought and sold over
the years.
These are some of the things I am concerned with.
We also filter certain prefixes and take other mundane
measures.
I have network drops that come from NY, CA, and the
Internet.
I have other Business Relationships with a variety of
other companies for instance, that likely have the
same need for connectivity to each of the two main
junctures and many of the others in bwetween.
Keep it simple.
I run an RFC1918 network in my comapnies network for
instance. However, since the last merger, I found the
network with not one but 2 difference class B address
ranges that I had to use on my network.
One was subsequently given back to one of the parent
companies.
However, I had to migrate out of it without impacting
production.
In addition, since there were some issues regarding
security and usability, I had to migrate the bulk of
my RFC1918 addressing from a full class B to only a
quarter of a class B.
I have about 14,000 users and about 4000 PCs that wer
of concern and about 8000 devices overall - remember
every device (printer, PC, timeclock, embedded
devices, security devices, and infrastructure device)
is part of this "pretzel".
So subnetting became my friend.
Also, it was much easier since the bulk of me network
is Layer 2 and I primarily use only one routing
protocol across my "company" network and then I only
have to worry about redistribution in a few edge
devices.
However, after wresting with with everything and a
year and a half later, I have removed the majority of
the pretzel aspects of this network.
As a result 1-4ms round trip is the typical round trip
time anywhwere internally on the network.
So I don't think we can get much faster.
As far as migration issues, we have not had any to
speak of. I did find a blackhole or two and took care
of those as they became apparent (remember when these
things get reported - people don't say "Can you fix
the blackhole").
I'm finshing upgrading the Core and Distribution
Layers this summer to Redundant Sup720's and 4515's
throughout and this should give me more tools to
effect my ultimate goal of End-to-End QoS, and prepare
for the final stages of migrating those last legacy
Access-layer devices.
Later.
The biggest hurdles you may face are probably:
1. Common Juncture Points
2. To NAT or Not (Existing NAT)
3. Redistribution (maybe or maybe not)
4. IP Address Schemes - may come in to effect later.
5. Policy Routing
6. Infrastructure Services: DNS, WINS, etc.
7. Don't forget about other protocols like IPX, SNA,
etc. It is a possibility I have not heard you rule
out.
As far as joining the two networks, I'd do some or all
of the following:
1. Perform a complete network discovery on both
networks - being particular to which prefixes both
use, static routes, routing protocols, etc.
2. Verify as much as possible about the goals and
actual requiremens of each flow (may seem cumbersome,
but you'd be surprised) Remember you can use Netflow
or other like tools.
3. Once you have this information, then you can begin
to compare and contrast like and not-like elements.
4. Compare what you have to what you want to achieve
as your final goal, create a list of "deltas".
5. Prioritize your objectives.
6. Create a Proposal and Mini-Project Plan (other will
likely comment, so be open to suggestions).
7. Put together all that you have and and identify
milestones and opportunities.
8. Have a Bill of Materials and a Budget ready for the
purpose of remediating an problem areas or hiring
contractors or consulting staff etc.
9. Be prepared to show where effeciencies can be
gained (loss of head count)and where you will have to
increase support to help support the newly envisioned
architecture.
10. Be prepared to present a monitoring and
maintenance system (like CiscoWorks, MicroMuse, HP-OV,
etc.).
11. A lot of items can be done remotely and automated
if you have knowledgeable staff. Such as Dynamic
VLANs, Archiving of Configs, Updating IOS, etc. Be
prepared with solutions to remedy these items.
Remember the IP Scheme Migration is likely the least
of your worries. You'll have to contend with each
company's culture. Likely due the efficiencies
gained, there may or may not be head count reduction
and sometimes staff may leave on their own as they see
the writing on the wall (real or imagined).
Be prepared to suck the knowledge of the exisiting
infrastructures from those brains as efficiently as
possible. People skills are in order.
Just some ideas, use them as you like. I probably
left out a ton of stuff, but not seeing the networks
first and hand and giving you a quick ten-minute's
worth of issues I've had to deal with in the past that
come to mind.
So feel free to add or take away.
No flames please, I know everyone has their own
preferences.
--- repaka r <r_repaka@yahoo.com> wrote:
> Hi Raminder,
>
> This involves complete merging..example.If company
> X has bought company Y then all the company Y's
> LAN/WAN/Security and infrastructure becomes Company
> X's property. In this type of scenarios..what kind
> of discovery needs to be performed and what are the
> steps that needs to be considered ot make it a
> successful migration with minimal downtime.
>
> I feel
>
> 1) IP addreessing needs to be considered-If there
> is a conflict in IPsubnets of X and Y then Applying
> NAT
> 2) Discovery on routing protocols for
> redistrubution [assuming X and Y are running on
> different protocols]
> 3) Discovery on the type of applications
>
>
> These are the few points in top of my head..any
> additon to this is appreciated.
>
>
> Raminder Sarna <raminder_sarna@yahoo.com> wrote:
> Hi Repaka,
>
> are you only talking of a layer 3 merger ?? or there
> is a layer two component as well ..e'g FR PVC moves
> etc ?
>
> --- repaka r wrote:
>
> > Hi,
> >
> > Could some one explain me the steps that needs to
> > follow in migrating two networks basially, Company
> > X's network migrating with company Y's
> network.,What
> > type of disovery needs to be perfomed ?
> challenges,
> > etc
> >
> > Any help on this is highly appreciated.
> >
> > Thanks.
> > CCIESEC
> >
> >
> >
> >
> > __________________________________________________
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> >
>
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