IP address block migration tips?

[ShackDaddy]

Sometime during the next couple of weeks my company will be switching our external class C network for another. I'm trying to make sure that I don't leave anything undone.

We host our own public DNS and use our ISP's DNS servers as secondaries. I will have to reconfig our external router and our firewall to match the new scheme.

I use SprintLink as an ISP, and have had four class C's from them over the last six years. In practice, we use two of them in a CIDR block, but will be moving down to a single class C provided by a recent aquirer.

What sorts of lead-time would you think I would need with my ISP to make the changes? Is this likely to be fairly painless, as far as dealing with service providers go? I know I will have my work cut out for me as far as reconfiguring my own systems, but I'd like to think that the things out of my control will be taken care of quickly.

 

[iggystar]

My only advice is don't beleive what they tell you and be certain you verify everything yourself. My company had a tuff time with some DNS issues many because a service provider was being a giant speed bump. Give them as much warning as you can. I've always found them to be horribly slow and about as nimble as a cement truck.