Hi,I am in the process of migrating a charity over to UFB Fibre.The catch is that the charity has its sole MX record currently pointing at the current Voda/Telstra Cable IP address. There is no secondary MX record set, so when the connection is down, emails bounce (or get queued on the sending server). When considering the best migration strategy, I started wondering if there was any issues running both internet connections live in parallel at once on the same network. Since I have never been in a position to have two live internet connections onsite together, I have no experience of whether this is even feasible or not.What I was pondering about was:External IP address 1 --> Cable --> Modem --> Router 1 (gateway 1)External IP Address 2 --> UFB --> ONT --> Router 2 (gateway 2)I would envisage setting the routers to be in the same subnet, but on different IP addresses and connect them together on the Lan side via a switch.The SBS2008 server already acts as the main gateway for all the client computers internally and also handles the DHCP allocations, so DHCP would be off on both routers (as it is now anyway).What I would envisage would be that incoming requests from the internet (pointed at either of the external IP addresses) would come up whichever connection they were targetted at. Internal traffic heading outwards would be directed at whichever gateway was set in the SBS server (either Gateway 1 or Gateway 2 depending on where we are in the migration process). I am presuming I would also have the correct gateway address set in both routers, so that they are told to send external requests to the main live gateway. (I know you can also do weighted routing rules, but this is where my current knowledge starts gets a bit hazy, but I get the basic concept, just never had to do it, so have no experience)What I am hoping for is that most traffic heading outwards will use the main gateway chosen at that stage (starts with Gateway1 but gets switched to Gateway 2 once ready for that switchover), but that the other internet connection will also remain "live" and connected so that incoming traffic from the internet is pointed to the other connection and still arrives too (ie no outage of emails or services during DNS propagation etc). I suspect that this would work for internal traffic just fine, as it would pretty much ignore the other connection (and wouldn't even know about it). However, I wasn't sure if say incoming OWA requests from the non-main gateway, would respond back through that same gateway it arrived through, or whether it would always head out the main gateway. It if always used the main gateway, then this would mean that OWA was broken for anyone connecting from home through NAT as the response would come from a different IP address than the request was sent to. Services onsite include:VPN connectionRemote Desktop Connections to a serverSBS2008 Exchange MailboxesMX receipt of Email from IP address.SBS2008 OWASo is this likely to work?Is it over complicating things?Is there a simpler way to keep everything smooth in the transition from Cable to UFB Fibre?(The most simple method I could think of is probably to add the new IP address as the secondary MX record (or as the main record) in advance, then do a hard swap of connections, but the DNS will have already got both IP addresses ready to receive mail, so should just work. I would then have to warn people that remote services using the DNS names would fail during DNS propogation time if they were pointing to the wrong IP)So, even if I don't connect both at once (and instead do the twin MX records route or another work-around), I am interested to use it as a learning experience anyway, to better understand the implications of routing twin internet connections, and any implications of such a setup.UFB should be live on 29th July, so I am in the planning stage right now before it arrives.The final configuration we are aiming for is for everything to be working on just the UFB Fibre connection, having been smoothly migrated over from Cable, with minimal downtime for 30 remote staff, and no lost emails.... and the Vodafone Cable connection disabled and cancelled. It is the smooth hassle free switchover than I am currently working out how to achieve.Any thoughts in this process would be useful.ThanksMike
↧