I have a customer that has been testing Force10 VLT with peer routing and VMWare and has encountered the warning message on all hosts during failover of the switches (S4810’s) only when the primary VLT node is failed
“vSphere HA Agent, on this host couldn’t not reach isolation address 10.100.0.1”
Does this impact HA at all? Is there a solution?
Force10 is the legacy product name of DELL S-series datacenter networking. Force10 S4810's are datacenter L3 switches. If you don't know what Force10 VLT is look here. Generally it is something like CISCO virtual Port Channel (vPC), Juniper MC-LAG, Arista MLAG, etc.
I think my answer can be valuable for broader networking and virtualization community so here it is ...
- Force10 VLT is used for multi chassis LAG capability
- Force10 VLT peer routing is enabled in VLT domain to achieve L3 routing redundancy
- 10.100.0.1 is IP address of VLAN interface on Force10 S4810 (primary VLT node) and this particular VLAN is used for vSphere management.
- 10.100.0.2 is IP address on Force10 S4810 - secondary VLT node.
- vSphere 5.x and above is used.
- ESXi hosts in the cluster are sending heartbeat beacon to each other. This should work ok during primary VLT node failure.
- ESXi hosts are also pinging HA isolation addresses (Default HA isolation address is default gateway therefore 10.100.0.1 in your particular case). This doesn’t work during primary VLT node failure.
- It is just informative message because algorithm (1) works correctly and there is still network visibility among ESXi hosts in the cluster.
- From vSphere 5 and above there is also storage heartbeat mechanism which can eliminate network invisibility among ESXi host in the cluster.