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Getting ready to switch ISP - minimalize dns replication issue
Have multiple web/email/app servers that are all associated with external ip addresses that will change when i go to a different provider. We handle DNS in-house. The registrar currently makes reference to my 2 name servers on my current provider block. The new provider will give me our ip address up front so i can make inital configurations. My idea was to create 2 additional name servers with the new ip addresses prior to the actual rollout so as to replicate accross.
proposed idea =
current:
ns1.oldprovider.com = online
ns2.oldprovdier.com = online
ns3.newprovider.com = offline
ns3.newprovider.com = offline
day of rollout:
ns1.oldprovider.com = offline
ns2.oldprovider.com = offline
ns3.newprovider.com = online
ns4.newprovider.com = online
ns1-ns4 would all be replicated accross the internet but only 50% available at any given time. the day of rollout i would make all the config changes on my local dns to reflect the new ip addresses once the new provider is live - a step i must take because i only have the 2 name servers. ns1 will become ns3 and ns2 will become ns4.
Unless there is a much easier way to do this....but i have been instructed to change ISP with at most 1 hour of downtime / can't wait the 24-36 hour dns replication time.
Ideas or thougts?
proposed idea =
current:
ns1.oldprovider.com = online
ns2.oldprovdier.com = online
ns3.newprovider.com = offline
ns3.newprovider.com = offline
day of rollout:
ns1.oldprovider.com = offline
ns2.oldprovider.com = offline
ns3.newprovider.com = online
ns4.newprovider.com = online
ns1-ns4 would all be replicated accross the internet but only 50% available at any given time. the day of rollout i would make all the config changes on my local dns to reflect the new ip addresses once the new provider is live - a step i must take because i only have the 2 name servers. ns1 will become ns3 and ns2 will become ns4.
Unless there is a much easier way to do this....but i have been instructed to change ISP with at most 1 hour of downtime / can't wait the 24-36 hour dns replication time.
Ideas or thougts?
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SOLUTION
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Fine, so here are your steps:
1.) Add secondary MX records for your domain with higher number (higher number=lower priority MX)
1b.) If you want to speed up transition process, lower TTL values, also SOA Time To Live, in your old DNS zone settings. Lower TTL down from default 24 or 48 hours to an hour or two, or even less, but an hour is enough.
2.) Setup your new server and make sure all is working fine, all websites, all databases, all mails
3.) Setup your new DNS, and, if it is on YOUR domain AND will have different name as your old DNS servers, don't forget to register those new DNS server name, for example, ns3.yourdomain.com, at your domain registrar and tell them it is for DNS server! Registering a sub-domain, for example, ns3.yourdomain.com as DNS server, needs some extra steps at your registrar, yhich will register this name in DNS namespace.
4.) Test your new server from your home computer, temporarily assigning your new DNS server's IP as your only DNS server for your home computer. Doing so, you will emulate as your new server is already in production, but only you will see it.
5.) When everything works fine, you are ready to either:
- change NAMEs of your dns servers at your registrar, if your old DNS was, for example, ns1.yourdomain.com, and your new DNS is ns3.yourdomain.com
- or change IPs of your DNS servers, if your old and new DNS servers will have the same name, only IP will be different
6.) After TTL time your transfer will be visible to whole internet and you are done. Hopefully with no problems.
1.) Add secondary MX records for your domain with higher number (higher number=lower priority MX)
1b.) If you want to speed up transition process, lower TTL values, also SOA Time To Live, in your old DNS zone settings. Lower TTL down from default 24 or 48 hours to an hour or two, or even less, but an hour is enough.
2.) Setup your new server and make sure all is working fine, all websites, all databases, all mails
3.) Setup your new DNS, and, if it is on YOUR domain AND will have different name as your old DNS servers, don't forget to register those new DNS server name, for example, ns3.yourdomain.com, at your domain registrar and tell them it is for DNS server! Registering a sub-domain, for example, ns3.yourdomain.com as DNS server, needs some extra steps at your registrar, yhich will register this name in DNS namespace.
4.) Test your new server from your home computer, temporarily assigning your new DNS server's IP as your only DNS server for your home computer. Doing so, you will emulate as your new server is already in production, but only you will see it.
5.) When everything works fine, you are ready to either:
- change NAMEs of your dns servers at your registrar, if your old DNS was, for example, ns1.yourdomain.com, and your new DNS is ns3.yourdomain.com
- or change IPs of your DNS servers, if your old and new DNS servers will have the same name, only IP will be different
6.) After TTL time your transfer will be visible to whole internet and you are done. Hopefully with no problems.
ASKER
Sorry for the delay, I only have one remaining question. Can I publish a Name Server even though it will be offline for a week or so? As long as I have at least one Name server online that can correctly resolve I should be ok yes?
Yes, you may have multiple nameservers - even if they are not all active. The nameservers that are offline will be listed as 'lame' nameservers (meaning they are not responsive) until they are brought online.
When you are ready to make your transition, simply shut down the servers that contain the old information. Remember though, if you don't set the TTLs down to a low number shortly before the transition you will experience a latency as cached DNS records expire on servers across the internet.
When you are ready to make your transition, simply shut down the servers that contain the old information. Remember though, if you don't set the TTLs down to a low number shortly before the transition you will experience a latency as cached DNS records expire on servers across the internet.
ASKER
Thank you both very much and sorry for the delay.
ASKER