Nexus 93180YC-EX cant configure static ARP for Microsoft NLB

[rikelme10]

I have two Nexus 93180YC-EX (NX-OS 7.0(3)I7(3)) whit HSRP configuration.

I need to configure a static ARP in the vlan interface for NLB to work, but when I tried it, I got this error:

Invalid MAC address. Multicast MAC address cannot be used.

This is the command:

ip arp 192.168.40.243 03BF.C0A8.28F3

this is the interface configuration:
no shutdown
no ip redirects
ip address 10.9.50.103/24
ip router eigrp NEXUS_EIGRP
ip passive-interface eigrp NEXUS_EIGRP

I do not know if there is another way to configure this, I´m looking for a workaround.

Regards

[Francesco Molino]

Hi

Have you tried adding the mac address command first:

mac address-table static multicast 03bf.xxxx.xxxx vlan XX interface ethernetX/X

And then add again ip arp command under the L3 interface.

I'm sorry i don't have any Nexus 9K with your nxos version right now but I do have N9k running 9.2(1) with this configuration and everything works as expected.

[rikelme10]

Hi Francesco

I could add these commands:

vlan configuration XX

layer-2 multicast lookup mac

mac address-table static multicast 03bf.xxxx.xxxx vlan XX interface ethernetX/X

But when I tried add ip arp command under the L3 interface I got the same error.
I don't know if it enough with these command for works it.

thanks and regards

[Andrea Testino · Accepted solution]

Hi,

This is supported starting on release NX-OS 9.2(1) and later hence why you are getting an error in 7.0(3)I7(3).

Here's the NLB Configuration Guide for the 9.2(x) train:

Cisco Nexus 9000 Series NX-OS Multicast Routing Configuration Guide, Release 9.x

Be mindful of the Guidelines and Limitations as well (noting two here):

• NLB is supported on Cisco Nexus 9300-EX, Cisco Nexus 9300-FX, Nexus 9300-FX2 platform switches, and Cisco Nexus 9500 platform switches with N9K-X9700-EX line cards. Multicast NLB is not supported on the Cisco Nexus 9500 modules with N9K-C9508-FM-2, N9K-C9516-FM-E2 line cards, or the Cisco Nexus 9300 and 9364C switches.

• NLB is not supported on the Cisco Nexus 9500 platform switches with -R line cards.

Thanks!

[rikelme10]

Hi Andrea

You are right, this is supported on release NX-OS 9.2, but for the switch 93180YC-EX the suggested versions are 7.X also I have another problem, Im not sure if the NX-OS 9.2 support FEX for this model, I found this for the 9.x release:

Full FEX module support has been added for the following switches:

■        N9K-C9336C-FX2

■        N9K-C93108TC-FX

■        N9K-C93180YC-FX

■        N9K-C93240YC-FX2

Thanks and Regards

[rikelme10]

Hi Andrea

You are right, this is supported on release NX-OS 9.2, but for the switch 93180YC-EX the suggested versions are 7.X also I have another problem, Im not sure if the NX-OS 9.2 support FEX for this model, I found this for the 9.x release:

Full FEX module support has been added for the following switches:

 N9K-C9336C-FX2

 N9K-C93108TC-FX

 N9K-C93180YC-FX   

 N9K-C93240YC-FX2

Thanks and Regards

[lietadielko]

Hi guys, 

were you able to get Multicast NLB working on 93180YC-EX or FX on the newer code? 9.2(1) or later?

to me it looks it is still not supported. I can add static ip arp entry, but not the static mac-address table entry. 

C93180YC-FX(config)# mac address-table static 03bf.0a00.4a0f vlan 500 interface Eth1/8

Invalid MAC: multicast/broadcast not supported!

I am using 9.3(3) code.

the reason I am asking is that one source mention that Microsoft NLB is supported from 9.2(1) on all 9300-EX and 9300-FX platforms, but then it is stated that Multicast NLB is not supported on Nexus 9300.

• NLB is supported on Cisco Nexus 9300-EX, Cisco Nexus 9300-FX, Nexus 9300-FX2 platform switches, and Cisco Nexus 9500 platform switches with N9K-X9700-EX and N9K-X9700-FX line cards. Multicast NLB is not supported on the Cisco Nexus 9500 modules with N9K-C9508-FM-2, N9K-C9516-FM-E2 line cards, or the Cisco Nexus 9300 and 9364C switches.

so to me it looks, that only unicast NLB is supported. 

thanks

Martin

[Andrea Testino]

Martin (@lietadielko),

You are likely missing some CLI configuration to get this working (assuming none of the limitations apply to your setup). Have you followed the steps to enable Multicast NLB on a Nexus 9300 running 9.3(3) as stated in the 9.3(3) Multicast Configuration Guide? 

Exerpt from the guide:

"

Multicast Mode

Multicast mode assigns a unicast IP address to a non-Internet Assigned Numbers Authority (IANA) multicast MAC address (03xx.xxxx.xxxx). IGMP snooping does not dynamically program this address, which results in flooding of the NLB traffic in the VLAN. Refer to Option 2A for an example of how to configure for this mode. The following example shows how to configure for IGMP Multicast Mode:

Example 1: Static ARP + MAC-based L2 Multicast Lookups + Static Joins + Non-IP Multicast MAC

This option does not require a PIM-enabled SVI or the IGMP snooping querier; works with non-IP multicast applications (custom applications).

Note	The hardware profile multicast nlb CLI must be enabled on the switch to support Multicast Mode.

1. Configure a static ARP entry that maps the unicast IP address to a multicast MAC address, but this time in the non-IP address multicast range:

interface Vlan10
no shutdown
ip address 10.1.2.1/24
ip arp 10.1.2.200 03bf.0000.1111

2. Enable MAC-based Layer 2 multicast lookups in the VLAN (by default, multicast lookups are based on the destination multicast IP address):

Note	You must use MAC-based lookups in VLANs where you want to constrain IP address unicast packets with multicast MAC addresses.

vlan configuration 10
layer-2 multicast lookup mac

3. Configure static MAC address-table entries that point to the interfaces connected to the NLB server and any redundant interface:

mac address-table multicast 03bf.0000.1111 vlan 10 interface Ethernet8/2
mac address-table multicast 03bf.0000.1111 vlan 10 interface Ethernet8/4
mac address-table multicast 03bf.0000.1111 vlan 10 interface Ethernet8/7

"

I tested the above in a lab NX 9300-EX (FX as well) running 9.3(3) without any issues. Sample:

93180YC-EX(config)# hardware profile multicast nlb 
93180YC-EX(config)# interface vlan 99
93180YC-EX(config-if)# no shut
93180YC-EX(config-if)# description Support Forum Test
93180YC-EX(config-if)# ip address 10.1.2.1/24
93180YC-EX(config-if)# ip arp 10.1.2.200 03bf.0000.1111
93180YC-EX(config-if)# vlan configuration 99
93180YC-EX(config-vlan-config)# layer-2 multicast lookup mac
93180YC-EX(config)# mac address-table multicast 03bf.0000.1111 vlan 99 interface port-channel 1
93180YC-EX(config)# show module
Mod Ports             Module-Type                       Model          Status
--- ----- ------------------------------------- --------------------- ---------
1    54   48x10/25G + 6x40/100G Ethernet Module N9K-C93180YC-EX       active *  

Mod  Sw                       Hw    Slot
---  ----------------------- ------ ----
1    9.3(3)                   3.0    NA  

Hope that helps!

[lietadielko]

Thanks a lot Andrea for your very quick response :) much appreciate that!!!  

yep, I had a typo in my config. I used mac address-table static ... with Multicast MAC address, which was giving me an error message. 

example of my wrong config....

Leaf-1(config)# mac address-table multicast  03bf.0a00.4a0f vlan 1 interface Ethernet 1/1

vlan lookup mode is IP, configuration cached

Leaf-1(config)#

Leaf-1(config)#

Leaf-1(config)#  mac address-table static 03bf.0a00.4a0f vlan 1 interface Ethernet 1/1

ERROR: Multicast/Broadcast MACs are not supported!

What also confused me was the limitations in 9.3(3) Multicast Configuration Guide, where it is also stated..that:

"Multicast NLB is not supported on the Cisco Nexus 9500 modules with N9K-C9508-FM-2, N9K-C9516-FM-E2 line cards, or the Cisco Nexus 9300 and 9364C switches." so I quickly though, that Multicast NLB is not supported, just Unicast NLB. 

have a great weekend. 

best regards, Martin

[Andrea Testino]

Martin,

Glad you caught on the typo! I agree that the guideline bullet point you're noting here could be clearer. The "Nexus 9300" is referencing the 1st generation N9Ks in case you were curious though!

Regards,

[lollike]

Hi,

I need NLB support on  93180YC-EX with 9.3.X software. Servers are placed on the Nexus access switches but the SVI and ARP entries are (for now) on a VSS cluster. NLB works in the servers connected to VSS.

The Nexus network i 3-layer model with DIST-AGG-ACC and the DIST is connected to the VSS cluster on L2. 

My question is: Must the "hardware profile multicast nlb" and "layer-2 multicast lookup mac" be applied to all Nexus switches or just the Nexus Access switches. 

Best Regards,

Thomas  

[jesper_petersen]

Hi all

Does anyone know what the command

hardware profile multicast nlb 

actually does?

I can find zero documentation about that command and I'd like to know if it imposes any behavioral changes for existing multicast traffic.

Thanks 

[Francesco Molino]

This command will enable multicast mode support.

Check this link:
https://www.cisco.com/c/en/us/td/docs/switches/datacenter/nexus9000/sw/93x/multicast/b-cisco-nexus-9000-series-nx-os-multicast-routing-configuration-guide-93x/b-cisco-nexus-9000-series-nx-os-multicast-routing-configuration-guide-93x_chapter_01001.htm...