Re: Issue Microsoft NLB - VMs in separate vSphare hosts

Andy_Z · ‎09-03-2020

Hi!

We have two vSphere hosts in two different rooms. Two NLB nodes on the one host, one (host nr.3) on the other.

NLB works as long as host nr.3 is not enabled.

vSphere hosts are connected via :

Cisco Catalyst 29xx Stack-able Ethernet Switch

|

Cisco Catalyst 4500 Virtual Switching System

|

Cisco Catalyst38xx stack-able ethernet switch

|

Cisco Catalyst 3650 Switch Stack

Now, just to be clear, I am not a network guy AND I don't have access to the shells on those devices - each output I want to get I have to request to the network team.

So, for the NLB cluster a VLAN was created and is supposed to be configured on all network trunks.

Also for the NLB a static cluster mac was defined and ARP entries have been added to the devices.

For the two switches connected to the two vSphere hosts I got the VLAN and ARP config entries.

01#sh ip arp 10.240.135.11
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.240.135.11           -   03bf.0af0.870b  ARPA

01#sh mac address address 03bf.0af0.870b
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
  30    03bf.0af0.870b    STATIC      Gi1/0/10 Gi1/0/11 Gi1/0/12 Gi1/0/17 Gi1/0/18 Gi1/0/19 Gi1/0/22 Gi1/0/23 Gi1/0/24 Gi2/0/10 Gi2/0/11 Gi2/0/12 Gi2/0/17 Gi2/0/18 Gi2/0/19 Gi2/0/22 Gi2/0/23 Gi2/0/24

02#sh ip arp 10.240.135.11
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.240.135.11           -   03bf.0af0.870b  ARPA

02#sh mac address address 03bf.0af0.870b
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
  30    03bf.0af0.870b    STATIC      Gi1/0/6 Gi1/0/7 Gi1/0/8 Gi1/0/10 Gi1/0/11 Gi1/0/12 Gi2/0/6 Gi2/0/7 Gi2/0/8 Gi2/0/10 Gi2/0/11 Gi2/0/12
Total Mac Addresses for this criterion: 1

BUT, for the two switches(routers?) in the middle, one has an ARP entry but no VLANs:

r1#sh ip arp 10.240.135.11
Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet  10.240.135.11           -   03bf.0af0.870b  ARPA


r1#sh mac address address  03bf.0af0.870b
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----

And the other has neither ARP nor VLAN. But our network support guy told me that is fine, because the switch/router "is not learning mac" - whatever that means.

So, I am lost in here. Is the network guy right, that the one device does not need ARP and VLAN entries, or is that one of the config errors.

I saw this thread: https://community.cisco.com/t5/....

There it says:

NLB mode

Switch configuration

Router configuration

Multicast

Mac-address-table static 03bf.xxxx.xxxx vlan y interface <int1> <int2>

n7k[5.2(1)]: mac address-table multicast 03bf.xxxx.xxxx vlan y interface <int1> <int2>

Arp <virtual IP address> 03-bh-xx-xx-xx-xx arpa

So my understanding would be that even a router should have an ARP entry.

Any suggestions are highly welcome. I have double checked the windows NLB settings on all three nodes and I don't see any windows config issues.

Thanks,

Andy

Andy_Z · ‎09-04-2020

Why would this command not show port 2/0/25:

02#sh mac address address 03bf.0af0.870b
          Mac Address Table
-------------------------------------------

Vlan    Mac Address       Type        Ports
----    -----------       --------    -----
  30    03bf.0af0.870b    STATIC      Gi1/0/6, Gi1/0/7, Gi1/0/8, Gi1/0/10, Gi1/0/11, Gi1/0/12, Gi2/0/6, Gi2/0/7, Gi2/0/8, Gi2/0/10, Gi2/0/11, Gi2/0/12

when this command shows the port having vlan30 allowed:

02#sh run int Gig 2/0/25
Building configuration...

Current configuration : 141 bytes
!
interface GigabitEthernet2/0/25
switchport trunk allowed vlan 1-3,30,199,301,500,501
switchport mode trunk
channel-group 1 mode on
end

Port 2/0/25 is the port connecting this switch to the neighboring switch on the path to the other cluster nodes.

Is there any trick to see the VLANs on a port in Cisco Prime? There is a VLAN column in the "Physical Ports" section, but it only displays one VLAN name which is not true for some ports.

Thanks,

Andy