Switch VRRP setup passing through two FlexFabric units each having uplinks

[WBeckers]

Small question on  VRRP

I have the following configuration on FlexFabric

Configuration:

Switch  1     -----------------------    FlexFabric 1

      |                                                   |

      |                                                   |

      |                                                   |

Switch  2     -----------------------    FlexFabric 2

Issue: 

Switch 1 sends VRRP to Flexfabric 1.

as it is a broadcast message it is expected the VRRP to 

arrive on FlexFabric 2 who will broadcast to Switch 2

That is Switch 1 knows Switch 2 has received its VRRP.

Unfortunately this does not occur.

Both Switch 1 and Switch 2 think they are Master. That is the VRRP packet is not routed via the FlexFabric to the opposite switch.

FlexFabric 1 in Bay 1 has UplinkSet_A1  active.

FlexFabric 2 in Bay 2 has UplinkSet_A2  active.

Any idea why the VRRP routing via the FlexFabric is not working

Regards and thanks in advance.

[Steven Clementi]

Are the ports on FlexFab1 ONLY connected to Switch 1? and FlexFab2 ONLY to Switch 2?  (based on your primitive (pardon the expression, but for lack of a better one this early in the morning...) wiring diagram.)

If so, you may need to rethink this configuration.

Packets will not route between Modules.  The only traffic that passes between modules is inbound to the servers or outbound from the servers.

Someone please correct me if I am wrong... I don't have much experience with virtual routing (I assume you are using Cisco Nexus switches or similar?)

[Hongjun Ma]

VC will never switch a packet it received from uplink back to another uplink(even on another module) within the same vlan. this is essentially creating a vlan loop.

vc internall map the same vlan to different vlan number so you can achieve active/active uplink.

usually for VRRP/HSRP, you want to use the direct link between two switches. I see there is a link between switch 1 and switch 2, why can't you use that link for VRRP hello packets?

[WBeckers]

We want to be able to detect failures in the C7000/ FlexFabric units.

The monitoring is done via external switches using VRRP.

(the internal VRRP capabilities of FlexFabric are not used)

Indeed the FlexFab 1 is solely connected to Switch1

FlexFab2 is solely connected to Switch2. Switch 1 and Switch 2 are a switchpack.

It is assumed the VRRP packets are forwarded to FlexFabric2 via the bay interconmnect.

Switch  1     ------>----------------    FlexFabric 1 in bay 1

                                                         |

                                                        V interconnect

                                                         |

Switch  2     ------<----------------    FlexFabric 2 in bay 2

It is switch1 sending the VRRP packets.  As long switch2 receives vrrp packets it will stay passive in slave mode.When the vrrp no longer arrives on switch2 it will  evolve to Master and starts sending  VRRP packets and other traffic. That is as soon the vrrp chain is broken the slave will become Masters and will behave accordingly.

Switches are not Cisco, however for purpose of discussion. please assume thes are Cisco.

May be this setup needs some tuning, if it shall be setup different I am interested to learn how.

Regards,

Wim Beckers