ISP Change-A couple questions

[Guest_imported]

I am in the process of changing ISP's and need a little help. I have a 2610 with VPN and a firewall set up within. Ip address will change, DNS will change and my access lits will have to change as well. My question is what do I have to do to get all the IP address changed? Can I set it up at one central location (I know, expecting too much)and have it flow down or will this be more than just a simple task?

To complicate matters, Instead of getting the router with Token Ring and Ethernet ports, my ISP decided to use my Exchange server as the Bridge between TR and Ethernet, one of the MANY reasons for the ISP change. Not knowing much about it when this was intially done, all decisions were left up to the ISP. So my Exchange server is the default gateway for all clients. Isnt there a NAT setting in the router to mask all traffic from the Exchange servers Ethernet NIC to a public IP? How do I change this? I may be asking too much but I really want to learn this stuff and save the Co a few $$ in the process. Any help is GREATLY appreciated. Worse comes to worst I can call in the SE's at the new ISP, but I'd rather not let it come to that.

Thanks,
Alex

 

[njang]

put your router before the exchange server

change the ip with the interface command
ip address <address> <mask>

now Nat your Exchange server (global config)
ip nat outside source static <address inside> <address outside>

prob want to make a global nat pool for your machines to connect out this is also dont global config:

ip nat pool net-20 <start pool> <end pool> netmask <mask>
ip nat inside source list 1 pool net-20

Now change the default route on your router to the next hop address of the ISP (global config again)
ip route 0.0.0.0 0.0.0.0 <next hop address> 1
next hop address will be supplied by the isp and the 1 = number of hops to get there

default gateway of all machines stay the same and this
as for DNS changing that you just config on the workstations
config should work assuming your IOS is 12.0+

-GoodLuck
-AKA Joe Digital

PS: if you need more help you can always fly me out there ..hehe