ACI F5 Configuration - Same IP Used for Multiple MAC Addresses

[zalu]

Hi all,

we have some problems in our ACI-F5 design. Here are some facts on design:

- Servers that we are using in F5 pools are connected on ACI Leafs

- Servers has only default route pointing to F5 Self floating IP

- F5 for this partition (VLAN) , has default route pointing to BD on ACI.  F5 connected via VPC to another pair of Leafs

- F5 is Active-Standby cluster with MAC Masquerade Address configured on both units

- Servers, VIPs and BD on ACI are all in same subnet.

This setup is same for different F5 partitions (VLANs). For all of them we see same problem in Duplicate IP Usage. 

ACI sees IP address from server coming directly behind leaf (where server is connected) with server real MAC address and ACI also sees server IP with F5 masquerade MAC coming from VPC links where F5 is connected. We have this problem for all servers. On some servers we see some DNS timeouts and we think it could be related with this setup and EP (servers) moving all the time between leaf where server is connected and VPC where F5 is connected. There is also Fault in ACI for coop dampening on spines, congaing MAC addresses of these servers that are flapping.

Any ideas how to fix this problem? 

Thanks,

zalu

[mhawwas]

I have same problem, have you got a solution yet ?

[zalu]

You have option to disable data plane learning for that EPG or to add those flapping IPs under EPG L4-L7 Virtual IPs.

Let me know if that helps.

br

[mhawwas]

Hi Zalu,

Thanks for your feedback ! It took for me some time to get reply from TAC and discuss this issue internal. 

Disable data plane learning on EPG was also the solution suggested by TAC. 

kind regards, 

[Andrzej_P]

Hi Zalu,

Have you looked here?: Cisco ACI and F5 BIG-IP Design Guide White Paper

Regards,

Andrzej

[zalu · Accepted solution]

Hi Andrzej, yes I did, but this would require some testing. I was searching for quicker solution. 

Thanks for reply.

Z