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New Member

VLAN standby issue

Hello All,

Need your help in the issue I am facing,

    I've two Cisco 4506 switches; on which I've created around 10 VLANs. now I have configured HSRP on both the switches. but it doesn't seem to be working as expected. one thing I want to know is do I need to configure a different standby group number for each VLAN interface created?

config is as given below

    For switch X :

    interface Vlan100

    ip address 10.11.1.2 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    interface Vlan101

    ip address 10.11.10.2 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    For switch Y:

    interface Vlan100

    ip address 10.11.1.3 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 preempt

    !

    interface Vlan101

    ip address 10.11.10.3 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 preempt

Regards,

Jigar Dave

Everyone's tags (1)
1 ACCEPTED SOLUTION

Accepted Solutions
Hall of Fame Super Blue

Re: VLAN standby issue

jigardave82 wrote:

Hi Jon,

KIK1#sh standby  brief

                    

                      |

Interface   Grp  Prio P State    Active          Standby         Virtual IP

Vl5         226  220  P Active   local           10.20.192.3    10.20.192.1

Vl605       105  150  P Standby  10.20.229.4    local           10.20.229.1

Vl815       96   220  P Init     unknown         unknown         152.12.2.1

Regards,

Jigar Dave

Dave

Okay, that's confusing .

Where are vlans 100 and 101 ?

And vlan 815 is in the init state.

How does this relate to your original post ?

Jon

10 REPLIES
Hall of Fame Super Blue

Re: VLAN standby issue

jigardave82 wrote:

Hello All,

Need your help in the issue I am facing,

    I've two Cisco 4506 switches; on which I've created around 10 VLANs. now I have configured HSRP on both the switches. but it doesn't seem to be working as expected. one thing I want to know is do I need to configure a different standby group number for each VLAN interface created?

config is as given below

    For switch X :

    interface Vlan100

    ip address 10.11.1.2 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    interface Vlan101

    ip address 10.11.10.2 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    For switch Y:

    interface Vlan100

    ip address 10.11.1.3 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 preempt

    !

    interface Vlan101

    ip address 10.11.10.3 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 preempt

Regards,

Jigar Dave

Dave

No, you can use the same group if you want. What does not seem to be working ?

Jon

Re: VLAN standby issue

Hello All,

Need your help in the issue I am facing,

   I've two Cisco 4506 switches; on which I've created around 10 VLANs. now I have configured HSRP on both the switches. but it doesn't seem to be working as expected. one thing I want to know is do I need to configure a different standby group number for each VLAN interface created?

config is as given below

    For switch X :

    interface Vlan100

    ip address 10.11.1.2 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    interface Vlan101

    ip address 10.11.10.2 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 priority 110

    standby 1 preempt

    For switch Y:

    interface Vlan100

    ip address 10.11.1.3 255.255.255.0

    standby 1 ip 10.11.1.1

    standby 1 timers 5 15

    standby 1 preempt

    !

    interface Vlan101

    ip address 10.11.10.3 255.255.255.0

    standby 1 ip 10.11.10.1

    standby 1 timers 5 15

    standby 1 preempt

Regards,

Jigar Dave

Hi Jigar,

Genrally it wont When you define the same HSRP group ID on multiple interfaces, they share the same HSRP virtual MAC address. In most modern LAN switches, there are no issues because they maintain a per-VLAN MAC address table. However, if your network contains any third-party switches, which maintain a system wide MAC address table regardless of VLAN, you can experience problems. If VLANs are not specified to a HSRP group, the VLANs default to Group 0.

what is the problem you are facing ?

can you share the show hsrp brief output of your active switch.

Ganesh.H

New Member

Re: VLAN standby issue

Hello,

My issue is that

both switches are located at abt 2 km away in physical area and power backup is not sufficient at one of the physical area  (as this switch is located at our new data center which is temprly. in construction mode). so when generator is drawn up, users are facing connectivity issue but as per my configurations the secondery switch would come and act as a primary switch (as preempt is already defined).

Pls suggest.

Regards,

Jigar Dave

Hall of Fame Super Blue

Re: VLAN standby issue

jigardave82 wrote:

Hello,

My issue is that

both switches are located at abt 2 km away in physical area and power backup is not sufficient at one of the physical area  (as this switch is located at our new data center which is temprly. in construction mode). so when generator is drawn up, users are facing connectivity issue but as per my configurations the secondery switch would come and act as a primary switch (as preempt is already defined).

Pls suggest.

Regards,

Jigar Dave

Dave

Preempt is only really relevant when you are tracking an interface or after the switches have been rebooted. If a switch fails then the other switch will take over whether you have preempt or not.

Can you post a "sh standby brief" as Ganesh suggested.

Jon

New Member

Re: VLAN standby issue

Hi Jon,

KIK1#sh standby  brief

                    

                      |

Interface   Grp  Prio P State    Active          Standby         Virtual IP

Vl5         226  220  P Active   local           10.20.192.3    10.20.192.1

Vl605       105  150  P Standby  10.20.229.4    local           10.20.229.1

Vl815       96   220  P Init     unknown         unknown         152.12.2.1

Regards,

Jigar Dave

Hall of Fame Super Blue

Re: VLAN standby issue

jigardave82 wrote:

Hi Jon,

KIK1#sh standby  brief

                    

                      |

Interface   Grp  Prio P State    Active          Standby         Virtual IP

Vl5         226  220  P Active   local           10.20.192.3    10.20.192.1

Vl605       105  150  P Standby  10.20.229.4    local           10.20.229.1

Vl815       96   220  P Init     unknown         unknown         152.12.2.1

Regards,

Jigar Dave

Dave

Okay, that's confusing .

Where are vlans 100 and 101 ?

And vlan 815 is in the init state.

How does this relate to your original post ?

Jon

New Member

Re: VLAN standby issue

Opps .. Typo mistake...    

Interface   Grp Prio P State    Active          Standby         Virtual IP

Vl1         1 110  P Active   local           10.11.1.2    10.11.1.1

Vl10       1 110  P Standby local          10.11.10.2   10.11.10.1

Dave

Hall of Fame Super Blue

Re: VLAN standby issue

jigardave82 wrote:

Opps .. Typo mistake...    

Interface   Grp Prio P State    Active          Standby         Virtual IP

Vl1         1 110  P Active   local           10.11.1.2    10.11.1.1

Vl10       1 110  P Standby local          10.11.10.2   10.11.10.1

Dave

Dave

So what actually happens.

Does one of you switches go down and then the users on both vlans cannot connect ?

Does it affect both vlans ?

Are you talking about devices connected into these 2 switches or end users connected into other access-layer switches that are then uplinked to these switches.

If users are on access-layer switches how are these switches connected to the 2 main switches. I ask because you said the 2 main switches are over 2km apart so was wondering how the access-layer switches were connected.

Jon

New Member

Re: VLAN standby issue

Hi Jon,

In my scenario, old data center and new data center is 2 km away, and both 4500 is connected with etherchannel on G1/0/4 & G1/0/8 to G1/0/4 & G1/0/8 to other switch.

Got my answer, actually I have checked in access layer switch, in that default gateway was given as old Core and switches are located at new DC,

Thanks for your help.

Jigar Dave

Re: VLAN standby issue

Hi Jigar

Jon is right.. in anycase if you want to create multiple virtual MACs or standby groups, make sure you are aware of the limitations of each switch for the max number of HSRP groups..

On a 4500 with SUP IV/V you can have a maximum of 256 unique HSRP group IDs... SUP 2 on a 6500 can only support 16 groups.. 3550 switches too support just 16 groups.. so make sure if you decide on different group IDs, your hardware can support based on the number of VLANs on your LAN network.. refer to this doc for more info on 6500 :

http://www.cisco.com/en/US/products/hw/switches/ps700/products_qanda_item09186a008011c6bb.shtml

hope this helps.. all the best..

Raj

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