Migrate RIPE IP range to new transit network

Ingo, how about a simple diagram showing before and after with more realistic IPs instead of 7.7.7.0/8?

Cheers - Bob

Hi Ingo,

Bob is right. One diagram says more than 1000 words ;-). I think, I suspect your problem. 

Hello

I mean something like the attached graphic

The 193-range would not have a direct next-hop to WAN
But I guess this should not be a problem right?

So would I just set up the ISP-B connection (80...-addresses), make that work and then remove the Gateway from the 193-range and everything would work smoothly?

Hi Ingo,

I think you need a smooth transition from ISP-A to ISP-B without facing a downtime. To do that, simply configure ISP-B on the UTM and define it in the UPLINK Balancing feature. Refer the KBA for configuration and details.

Hope that helps.

We currently already have multiple uplinks. That is not the question.

It is rather: how does the UTM handle traffic to/from the 193-range if this cannot directly connect the ISP
Basically it should be routed through the ISP and masquerading should not apply right?

So, I'm still not clear on where the 193 numbers live.  Are they Additional Addresses on eth8 or is there an Ethernet segment attached to eth8?  Will ISP A still have 192.114.251.2 on its router in your premises?

I have a client that uses Border Gateway Protocol to manage which ISP routes traffic to a public subnet they "own" - is this what you're trying to do?

Cheers - Bob

So, I'm still not clear on wherethe 193 numbers live.  Are they Additional Addresses on eth8 or is there an Ethernet segment attached to eth8?  Will ISP A still have 192.114.251.2 on its router in your premises?

Yes there is a segment on eth8 between the UTM and ISP-A router
ISP-As router will go out of service after the migration

ISP-B will have a router in the same VLAN (Layer-2 segment)

We do not want to do BGP on the UTM as I do not intent to give me the hassle ;)
The ISPs routers do BGP of course

Both ISPs are allowed to route the network as defined via RIPE DB

What I try to do: Migrate from one ISP to another at best without service interruption or at least with the shortest possible interruption

OK, that's exactly what I thought you wanted, Ingo, but I wasn't "seeing" the picture.  Your plan should work.

You could use Sachin's suggestion along with appropriate Multipath rules to smooth the transition, and then delete the items no longer needed afterwards.  Also, you may need new firewall rules for traffic coming from your private LANs to the Internet.  You will definitely need one or more firewall rules for traffic from the Internet to the 193 subnet.

Cheers - Bob

Thanks for the confirmation :)

It is basic routing to be honest, but it is better to check beforehand than to run into trouble and having to debug under timepressure

Thanks so far

Case closed