Static routing question

[Packet7hrower]

I’m sure this is doable - I’ve just never done it!

I have three locations.

Location A currently has direct fiber run to both Location B & C.

Location A houses the WAN Circuit and the MX, as well as the server infrastructure.

Location A & B are on the same local VLAN.

Location C is on a different VLAN. The default gateway is the local Layer 3 Switch, who’s last resort route is going to the MX at Location A.

I’m looking to place MX’s at both Location B & C.

At B & C, the Layer 3 Switches will route internal traffic over the local fiber, and any internet traffic upstream to the respective MX.

My question is - how would I setup the routes on the Layer 3 switch at Location A?

Location B still needs to pass traffic to Location C.

Will the Layer 3 switch at Location A be able to just figure it out? As long as it has a route to both B & C, I would assume it would just forward the flow direct to route going to C, correct?

[CharlieCrackle]

You need to determine what is doing the routing, the Switch or the MX  and then if possible make the MX on a separate network  so  you are not hair pining the traffic to the MX when it needs to go to a separate site.  It make sense that the MX does the routing but depending on the model  a layer 3 switch will have better performance.   If we assume that layer 3 switches will do the routing  then I suggest this approach  but it will mean readdressing site B.   You can still use the MX for DHCP just need a helper address on the Layer 3 switch.  (note: I made up the addressing for the example)

Diagram 1 is the Physical Connections

Diagram 2 is the Logical Network Diagram.

 

[cmr]

If you are adding MXs at each location, are you going to have an internet connection at each location, or is the plan to have internet at A into MX(A), fibre link to B into MX(B) and then LAN(B) and fibre to C into MX(C) and then L3 switch(C)?

If the above then are the fibres and servers plugged in to MX(A) or L2 switches?

[Packet7hrower]

Sorry - I should of been more clear!

So right now, A has the MX and two WAN Connections.

B&C have a direct Layer 2 SMF link going to the core switch at A.

I'm looking to add an MX to both B&C, along with a WAN Connection on each new MX.

Internet traffic at B&C would route out the new MX & WAN at the respective site, however, LAN traffic would route over the Layer 2 SMF link from the core switch at B&C, back to A, to access the Servers.

Essentially - I want to remove all internet traffic from having to route through A from B&C, but still retain LAN Access.

[cmr]

If you have a L3 switch at each site then you can do the below:

1. Create a transit VLAN that is used only for the SMF links and has an interface on each LANs core switch.
2. Set the default gateway on each core switch to point to the local MX internal IP
3. Create static routes for the LAN IP subnets at the other two sites pointing to the IP in the transit VLAN for the site.

For example site A has transit VLAN interface 10.1.1.1/24 and local subnet of 192.168.101.1/24 with the MX on 192.168.101.254.  Site B has 10.1.1.2/24, 192.168.102.1/24 and 192.168.102.254 respectively.

At site A the default gateway for the switch is set to 192.168.101.254 and a static route is created for 192.168.102.0/24 pointing to 10.1.1.2.