Diferents gateways to group of hosts on DLR

[konis]

Hi,

I was watching the video "VMworld 2014: NET1974 - Multi Site Data Center Solutions with VMware NSX" on  YouTube and the Speaker says that is possible define diferentes default gateways to groups of Host, using init script. Someone knows how can I do this ?

Thanks for your aid !!

[smitmartijn]

Hi,

I couldn't find the bit where he was talking about adding multiple gateways, but you can definitely do that. For instance, on Linux: Two Default Gateways on One System - Thomas-Krenn-Wiki

But, I would like to point out that you're looking at a Cross-vCenter presentation from 2014, which has changed a lot since then. The presentation Humair Ahmed (VMware PM) did in 2016 is more up to date: Solving Multi-Site Challenges With VMware NSX - YouTube

Also, what are you trying to solve? I'm generally not a fan of solving a network problem on the servers themselves, only complicates things.

[konis]

smitmartijn

Thanks for your aid.

You can find this on 35:48 minutes of video, when He mention local egress saying "Host on site A have DLR default gateway configured via site A EDGE GW using an INIT SCRIPT"

I will watch the video that you say. Thanks

I want to know how can I do a Local Egress with MSC. Resuming I would like to know how can I do active-active egress with MSC.

[smitmartijn]

Alright, when there's one topic that has changed since the video you were watching. 😉

Local Egress is now part of NSX itself and you don't have to do anything special on the hosts. Configure it inside NSX: Local Egress

[konis]

smitmartijn

I am using MSC (Metro storage Cluster) scenario.The video that I mentioned early treat this scenario and inform that is possible use diferents gateways on DLR, through init scripts, but don't show how.

I am looking for this information, because is pretty smart.

[bayupw]

That was for NSX version prior NSX 6.2.x which does not have a concept of Locale ID

The static route configuration is set using net-vdr command on DLR per ESXi host

It would be net-vdr -a to add the static route on DLR per ESXi host, http://chansblog.com/tag/nsx-net-vdr-command/

Now NSX 6.2.x introduces the concept of Locale ID for routes sent to the NSX Controller which the default value is set to NSX Manager's UUID.

Locale ID value is ignored if local egress not enabled (which enabled at NSX Edge/DLR deployment)

In vMSC environment, you can set the Locale ID per ESXi host level so each sites will have it's own static route.

Local egress with vMSC + static routes is only supported in scenarios with no DLR Control VM as far as I know.

This scenario is also described in the multi-site design guide https://communities.vmware.com/docs/DOC-32552

[bayupw]

Just want to add that in my experiences, local egress is not normally required for vMSC (especially from network point of view).

NSX optimises the egress but does not handle the local ingress very well.

Without ingress optimisation (for example Cisco LISP) there would be asymmetric routing and stateful services such as firewall, NAT, load balancer might break.

This blog post has a good explanation on ingress routing on stretched layer 2 network: Elver's Opinion: DC Ingress Traffic with Stretched Layer 2