New Broadband Provider, Best Practice

[-Dan]

Hello All

 

I have been a big fan of the site for a long time, but thought it was about time to sign up and join in!

So to kick things off, I have a question

 

I work in a school with about 700 computers running on a RM CC4 network Server 2003 R2.

We will soon be switching our broadband provider and thus our IP range will change.

 

We build all computers using PXE (initially, then use remote build), so when we populate the credentials of the computer this enters the computer into the DNS.

 

What is the best practice when switching ISP, edit the DNS or rebuild everything on the network?

Or is there more options to consider.

 

 

Dan

[synaesthesia]

How will the provision of external services change your internal network?

 

Here for instance we had an IP range system set out by previous county-wide initiatives (probably not the best description but you'll get my meaning!) and when changing over we retained the internal addressing schema to avoid having to re-address everything and all the related services.

[MattGibson]

We are in the process of changing ISP away from county. Internal range will stay the same. Just make sure when your External IP changes that you update everything that points back to the school such as your exchange server.

 

Also double check where the DNS records are for your school domain... do they stay with the old provider or transfer to the new, if they transfer you'll need to replicate A records and CNAMES.

[-Dan]

Invaluable information.

I am trying to get a clear picture in my head ready for this change. it's much clearer now.

 

Thank you.

 

 

Dan

[kcrick]

Hello - unsure technician here,

How do you go about retaining your old IP range when moving from LEA broadband to say, for example Virgin?

 

any information would be greatly received!

[sparkeh]

Hello - unsure technician here,

How do you go about retaining your old IP range when moving from LEA broadband to say, for example Virgin?

 

any information would be greatly received!

For us, when we moved away from LA, our new provider said what IP range do you want and just gave then our current one.

Your internal IP range, afaik, doesn't really matter to your provider (as long as they know what it is!).

[Oaktech]

Hi,

 

we've just done this and followed the following procedure

 

Register your domain with an external registrar if you don't already (ours was RM) this cost £9 we used vidahosts

Register your DNS with an external management company, again we used vidahosts who did it for free.

Recreate your external DNS structure with your existing IPs and set the ttl to something short.

 

press your new ISP for your new range of ips

if you are keeping your existing firewall/router create a set of nat rules in parallel with your existing firewall/routing rules, if you are going for new routing create a set of suitable rules. ready for switch over

when you come to switch over change the external dns to the new IP range as set out in your firewall/routing rules and watch it all kick off.

 

find out if your mail server currently uses smart hosts provided by your lea or isp and if those are going to continue. If you are going it alone remember you are going to tell any mail server to route via dns instead of smarthosts and you need to ensure your DNS has the appropriate mx records.

 

Also ensure your new ISP sets out any reverse dns lookups to help you remain trusted sending mail!

 

Internal dns doesn't really matter as long as you don't decide to change any external dns!

 

Any help?