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. And see here for current known issues.

New Member

standby between interfaces

Good afternoon,

There is a way to do a hot standby between 2 interfaces at the same router?

Something like HSRP between 2 routers, but I need to do between 2 interfaces, when one comes down, the order get its IP

Thanks

1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Blue

Re: standby between interfaces

Denis

You can use IRB (Intergrated Routing & Bridging) for this which allows you to bridge the 2 interfaces on the router ans and assign one IP address to the bridged interface , see attached link -

http://www.cisco.com/en/US/tech/tk389/tk815/technologies_tech_note09186a0080094663.shtml

Note that STP will block one of the links so only one link can be used at any one time.

Jon

9 REPLIES

Re: standby between interfaces

If you have the standby option, you'll do

int fa0/0

ip address 10.1.1.2 255.255.255.0

standby 1 10.1.1.1

int fa0/1

ip address 10.1.1.3 255.255.255.0

standby 1 10.1.1.1

Can you post what you're trying to do?

Thanks,

John

HTH, John *** Please rate all useful posts ***

Re: standby between interfaces

Are you wanting the same public IP assigned to a different interface? Do you have a static address assigned now? If so, what you want to do isn't possible that I know of. You won't be able to assign the address to the other interface because the router will tell you that the "address overlaps interface xx."

You can have different addresses assigned to your interfaces (they have to be in different subnets) and have routes force all traffic out one interface, and run ip sla to track that interface. If the interface goes down, all of your traffic can be pushed out of the other interface.

You can also just have two interfaces with two different addresses and run floating routes in your config.

ip route 0.0.0.0 0.0.0.0 fa0/0

ip route 0.0.0.0 0.0.0.0 250 fa0/0 254

OR

You can track the interface:

track 1 int fa0/0 line-protocol

ip route 0.0.0.0 0.0.0.0 fa0/1 track 1

I'm not 100% sure if the last one will work because I've never tried it. I'm not sure if the track line in the route statement will ONLY work if the tracked item goes down.

HTH,

John

HTH, John *** Please rate all useful posts ***

Re: standby between interfaces

What is the concern, device/service connecting the 2 routers will go down? i.e. redundant switch in between the 2 routers or WAN links (serial)?

There are alternatives in achieving that failover if you give us more info on how the two routers is connected.

New Member

Re: standby between interfaces

Like the file attached, If the interface fa0/0

goes down, I need that the interface fa0/1 gets the same IP and keep answering to computer

Re: standby between interfaces

Well, from your diagram it looks like you're still wanting HSRP. You would assign the 10.0.0.1 ip address as the standby address, but your physical interfaces would still have a different address assigned to them.

My 2811 does support it. I'm running Enterprise Services IOS on mine.

HTH,

John

HTH, John *** Please rate all useful posts ***
New Member

Re: standby between interfaces

but John,

I cant put the stanby IP the same as the other interface real IP.

Its overlaps the other

Hall of Fame Super Blue

Re: standby between interfaces

Denis

You can use IRB (Intergrated Routing & Bridging) for this which allows you to bridge the 2 interfaces on the router ans and assign one IP address to the bridged interface , see attached link -

http://www.cisco.com/en/US/tech/tk389/tk815/technologies_tech_note09186a0080094663.shtml

Note that STP will block one of the links so only one link can be used at any one time.

Jon

Re: standby between interfaces

I learn something new everyday. :-)

John

HTH, John *** Please rate all useful posts ***
New Member

Re: standby between interfaces

Thanks Jon, Im gonna test this solution

137
Views
0
Helpful
9
Replies
CreatePlease to create content