Nexus 9000 GLBP

[werdna118]

Does anyone know the reason why (according to documentation) the Nexus 9000 does not have GLBP but the Nexus 7000 does?

[InayathUlla Sharieff]

GLBP is not supported on N9K .

Is there a reason you want to use GLBP because if you use vpc, it gives you better load balancing than GLBP using VRRP or HSRP as both routers act as active-active FHRP gateway.

GLBP was a technology before we add support for active-active FHRP gateways in non-vpc environment.

this is what I can tell you based on my experience.

Regards

Inayath

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[werdna118]

Reason was the existing ASR routers use GLBP so it would be easier to integrate a GLBP capable device into the environment...but that can be changed, i'm not married to GLBP.

Essentially I'm Planning on running 2x Nexus 9ks with layer 3 which attach to 2x ASR routers for transit services. VPC doesn't really fit into this scenario as far as my understanding goes.

I always just assumed GLBP was the better option, but it looks like HSRP or VRRP are more widely supported??

And does this mean I should stop using GLBP to avoid corner cases like this in future, or should I just buy a Nexus 7000 series??

[njccnp]

When you say that you added support for active-active gateways in a non-vpc environment, what are you referring to? Customers have always had the workaround of creating two HSRP groups, but then the PCs on that subnet need to be split up between the two different Default Gateways. The benefit of GLBP is the ability to avoid this workaround, and have all routers active without the need for multiple groups and multiple Default Gateways on the PCs. Has this same ability been added to HSRP? Can the customer have active-active HSRP routers on a single subnet/VLAN, with a single HSRP group?

[sbhadrav@cisco.com]

GLBP provides automatic router backup for IP hosts configured with a single default gateway on a LAN.
Multiple first-hop routers on the LAN combine to offer a single virtual first-hop IP router while sharing
the IP packet forwarding load. Other routers on the LAN act as redundant GLBP routers that become
active if any of the existing forwarding routers fail.
GLBP provides load balancing over multiple routers by using a single virtual IP address and multiple
virtual MAC addresses. Each host is configured with the same virtual IP address, and all routers in the
virtual router group forward packets.
GLPB is VPN Routing and Forwarding (VRF) aware, supporting multiple routing instances. You can use
VRF-aware services to ping for hosts or to display ARP entries for a specific VRF. You can configure
GLBP so that traffic from LAN clients can be shared by multiple routers, thereby sharing the traffic load
among available routers.

[ajc]

Hi Bhadrav, is GLBP supported or not on Nexus 9K?. From the beginning of this post, it says NO, but looks like is now available. In fact, from the link: 

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/6-x/command_reference/show_612I22/b_n9k_show_command_ref/b_n9k_show_command_ref_chapter_0111.html

we can see there is a SHOW GLBP CAPABILITY.

Could you please clarify?

thanks