ISP Changes - Seeking assistance

[TechP74]

Due to family needs (small family business) I am now the System Admin for our company. This is not my normal job function so I am learning as I go. Not the best idea, I know, but we have no other choice at this time. I WISH I could hire a consultant.

So..I am asking for your help here. We are in the process of changing ISPs. In order for our email to work (using exchange 2003 on SBS Premium) what will I need to change...update? Will I need to contact the company our name is registered with? I am just not sure what steps I need to take when we receive our new static IP.

Thanks!

 

[artesian2000]

You will need to contact whomever hosts your current email mx record and have them update it with your new static once you get it. There may be a lag time for this to update and you could suffer some downtime on accessing your email for a bit.

 

[ncotton]

The downtime should (in writing) be about 12 hours, but you should see a downtime of 2-4 hours realistically, maybe even less.

Neil J Cotton
Technical Consultant
Anix Group Ltd

 

[brianinms]

It shouldnt take that long if they merely add the new address as an mx with a lower preference. Only problem will be the other servers that cache dns.

 

[ncotton]

yeah, the ISP (your hosts) end will be changed straight away, but thats the last link in the chain as far as incoming mail is concerned. Outgoing mail will be fine, but incoming requests will lead to mail delivery failures for upto 12 hours whilst the DNS flushes through for all other routes to be updated.

Neil J Cotton
Technical Consultant
Anix Group Ltd

 

[ChrisAC]

The best approach here is to reduce the TTL on the existing record to say 600 (ten minutes) a few days before the change over. Then once you change to the new IP address, the DNS record can be changed and because of the low TTL the new record should be fully propageted within 10-15 minutes.

You will only have a delay of upto 12 hours if you leave high TTL's on the incumbant MX record. Then you only have yourself to blame ;-)

Don't forget to change the TTL's back once the migration is complete.

Chris.


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Chris A.C, CCNA, CCSA
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