Cisco ACI MultiPod IPN Issue - Spine to N7K F3

[ITforever]

Hello,

We are working on bring up multi-pod connenctivity between 2 pods and we experience the issue with connectivity. The issue is between the spine and N7K F3 connectivity. F3 line card interface is configured as Layer 3(routed) and resource is allocated in VDC.

interface Ethernet2/3
mtu 9216
vrf member VRF_IPN
ip address 10.1.1.99/24
no shutdown

!

allocate interface Ethernet2/1-12

The interface shows up on N7K but we can't ping between them. 

We have the L3Out created on infra tenant and looks ok.

Is there anything specific on N7K side we might be missing? Or would that be more ACI side?

Thanks.

[Manuel Velasco]

Are you following any specific document to configure the multipod?  

If not, I would recommend to follow the white paper below, N7Ks are also used as the IPNs and the configuration is included.

https://www.cisco.com/c/en/us/solutions/collateral/data-center-virtualization/application-centric-infrastructure/white-paper-c11-739714.html

[ITforever]

Hi Manuel,

Thanks for your reply. Yes, I follow exactly this document and the below one:

https://www.cisco.com/c/en/us/td/docs/switches/datacenter/aci/apic/sw/2-x/L3_config/b_Cisco_APIC_Layer_3_Configuration_Guide/b_Cisco_APIC_Layer_3_Configuration_Guide_chapter_010011.html#id_29845

No luck yet :(

[Nik Noltenius]

Hi,

is the configuration shown all you have for this interface???

If so it seems a bit odd that you follow those two design guides but your config doesn't look anything like it.

If e2/3 is connected to a spine, you are missing the dot1q encapsulation, OSPF, PIM... Even the MTU doesn't add up.

This is what you should have:

interface Ethernet2/3
mtu 9216 ! or better 9150 do be consistent with ACI side

no shutdown

interface Ethernet2/3.4

mtu 9216 ! or better 9150 do be consistent with ACI side

encapsulation dot1q 4
vrf member VRF_IPN
ip address 10.1.1.99/24

ip router ospf <process-name> area <whatever you're going for, probably 0.0.0.0>

ip pim sparse-mode

ip dhcp relay address <Infra IP APIC1>

ip dhcp relay address <Infra IP APIC2>

ip dhcp relay address <Infra IP APIC3>

no shutdown

If you set up multi-pod correctly on the ACI side the spine interface encapsulates all traffic with VLAN4 and drops all your untagged ICMP-Requests.

Regards,

Nik

[ITforever]

Hi Nik,

Good pick up - I have been playing with the config and actually pasted the wrong/latest version. But I have tried as per the document, and it didn't work. Anyway, the issue was actually to do something with MPOD support for the version we use 3.0. We upgraded to v3.2 and it looks good now. 

But we came across another issue which I will open in a separate case. During the upgrade, the spines that are supposed to be connected to the Pod2 all have gone inactive. 

Anyways, thanks for all your help and guidance.