Cisco Support Community
cancel
Showing results for 
Search instead for 
Did you mean: 
Announcements

Welcome to Cisco Support Community. We would love to have your feedback.

For an introduction to the new site, click here. If you'd prefer to explore, try our test area to get started. And see here for current known issues.

New Member

HSRP

I am configuring HSRP on MSFC. I have a question that if I assign same HSRP group number on more than one subinterface what would be the disadvantages beside that it works.

7 REPLIES
Bronze

Re: HSRP

According to the docs, identically numbered HSRP groups use the same virtual MAC address, which might cause errors if you configure bridge groups.

New Member

Re: HSRP

another issue is that if if all interfaces are in same group & the standby priorities are also equal (i.e. 2 interfaces at priority 105), the vlan interface with the lowest (or highest?) IP address will be the next successor. I've seen this situation on one occastion, so it is best to have each vlan interface assigned a unique group number (0-255).

New Member

Re: HSRP

Thanks. Thats what I tought too

New Member

Re: HSRP

I too have a question regarding HSRP...We have a pair of 7507's running HSRP on the E0/0 int. All of our LAN devices are configured with a gateway of the HSRP address.

We're seeing traffic coming through the standby E0/0 interface. How would this occur?

New Member

Re: HSRP

HSRP only allows devices to use a virtual IP address to send data *to*.

Reply data could come from either (any) HSRP interface on the LAN depending on your implementation of routing protocols or static routing.

Outbound data could also go through a "standby" interface if sent by a server, router, or some other device that utilizes a routing protocol rather than just a default gateway pointing to the HSRP ip address.

Mick.

New Member

Re: HSRP

Understood, but these are MS Exchange servers on the LAN that the (2) 7507's support, so no unusual routing protocols are implemented.

I'm curious because we are implementing a policy route on the E0/0 int. to push this Exchange traffic down a particular PVC off the active HSRP router, so traffic shouldn't be going to the standby router at all on the LAN, correct?

New Member

Re: HSRP

With the exception of normal NT broadcasts, ARPs, and HSRP Multicasts, you shouldn't have anything going in on that interface if all of the devices on the segment are using the HSRP IP address.

Note: HSRP sends out multicasts every 3 seconds by default.

Mick.

99
Views
0
Helpful
7
Replies