What is the purpose of creating vmk3? What will be its function?
If you want vmk3 to communicate outside its subnet, to a subnet *not* already configured on the ESXi host, keep using static routes. The command will be as above:
esxcli network ip route ipv4 add -g 10.28.187.253 -n 192.168.10.0/24
Where 192.168.10.0/24 is the subnet you want to reach via vmk3. This can be considered a bad thing if you have many subnets to reach from vmk3, because that's many static routes on each host. But it should work.
For instance, let's consider you're using vmk3 for vSphere Replication traffic between Site A and Site B. For security, you'd like to keep replication traffic segregated. So at Site A, you have a vmkernel port created for vSphere Replication, call it vmk3, and vmk3 resides in subnet 10.28.184.0/22. At Site B, your vSphere Replication appliance lives in subnet 192.168.10.0/24.
You want to force traffic from subnet 10.28.184.0/22 (and therefore vmk3) at Site A to subnet 192.168.10.0/24 at Site B, you must configure a static route. The configuration would look like this:
esxcli network ip route ipv4 add -g 10.28.187.253 -n 192.168.10.0/24
You never have to configure a "default gateway" for vmk3 - rather you configure a static route. When the ESXi host needs to send traffic to the 192.168.10.0/24 network, it will look to see if it has a vmkernel port already in that subnet. It will see that it does not, so it will look at its routing table and find an entry that says to send traffic to the 10.28.187.253 address to reach that subnet. So again it searches for a vmkernel port from which send the traffic and it finds that vmk3 is, indeed, already on that subnet. ESXi will then forward traffic from vmk3, through the 10.28.187.253 gateway which eventually reaches the destination subnet.
Hope this helps,
Mike
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Mike Brown
VMware, Cisco Data Center, and NetApp dude
Consulting Engineer
Twitter: @VirtuallyMikeB
Blog: http://VirtuallyMikeBrown.com
LinkedIn: http://LinkedIn.com/in/michaelbbrown
