Multiple Interface with same VIP in same Router

[netbeginner]

Hi Experts,

Searching for whether "Is this possible to have multiple interface with same VIP on same Router". I am not finding this anywhere.

Requiring this for our HA/Traffic shifting to be work perfectly. If requested feature is not available...Pls suggest for alternate solution which cab be implemented without any downtime or service impact..

Rgds

***

[Aaron Harrison]

The answer would be 'it depends'... you need to describe what you are doing and why you need this to get a useful suggestion..

[netbeginner]

Hello Aaron,

As shared we require this feature to make our Traffic Failover functional.

We have two Cisco 3945 Routers and Cisco Cisco 2960-XR switches.

Cisco 3945 Router(Primary) is connected with Cisco 2960 XR First Switch.  and Cisco 3945 Router(Secondary) is connected with Cisco 2960 XR Second Switch.

HSRP instance is running on Both Routers Interface which are directly connected to their respective Cisco 2960 switches. As there is not cross connectivity as of now between Cisco 3945 pri router to cisco 2960 second switch and Cisco 3945 secondry router to cisco 2960 primary switch....traffic failover is not happening.

TO overcome this, we notice we have create above cross connectivity and make them functional using two interfaces per router with same HSRP VIP.

hope you understand requirement.

[Aaron Harrison]

Hi

The two 2960s should be connected together; is this not the case?

Aaron

[netbeginner]

Hi,

Obviously, we are having port-channel created between two Cisco 2960 switches. But same is not enough for traffic shifting...

[Aaron Harrison]

OK - I presume you mean that return traffic is still delivered to both routers when one is no longer connected to the LAN; i.e. when it's 2960 is offline?

In that case you need to either:

1) Redesign your router-->switch connectivity such that both routers are connected to both switches

-or-

2) Use features on the router to ensure that when the router cannot reach the LAN or when it is not the active HSRP member, it doesn't advertise (or advertises out an inferior route for) the local subnets

[netbeginner]

Hi,

thanks Sathvik, Probably there is some disconnect.!!

We already consider and also align with Aaron's point-1.  That's why initiated discussion to know if same HSRP VIP can be assigned on multiple interfaces with HSRP. so that I can connect One router with both the switches. and make traffic shifting functional.

[sathvik k v]

No, to what i know same VIP can not be used for multiple HSRP groups. Router will throw back a error message. You have use another IP in same segment and create one more group.

Can you explain the setup more in details. Like any IGP protocol used between the switches and routers ?

-Sathvik

[Jon Marshall]

Just so this doesn't get too confusing there is another post in this forum by same person asking the same question.

I answered in there and from the description given it's not clear why it is not working.

It does depend on routing ie. advertisement of DC subnets but that doesn't seem to be the problem being described by the OP.

See this link for details -

https://supportforums.cisco.com/discussion/12672661/data-haredundancytraffic-shiftingnot-functional

Jon

[sathvik k v]

If you say the etherchannle between two 2960 switches is not enough for traffic shifting, then please consider point 1 mentioned by Aaron.

-Sathvik