HSRP, Routing and ACL theory

Unanswered Question
Mar 19th, 2009


Say i have the below diagram:




DSwitch2 ---Trunk link to----DSwitch1

Distribution Switch1 is trunk to Distribution Switch2. Access switch3 is connected to Distribution Switch2.

For the testing that i have set:

1) DSwitch1 as the active for HSRP vlan 4 and DSwitch2 as the standby for vlan 4.

2) Both have the same access list pointing "In" in both DSwitches.

Now say i shut down the SVI interface of vlan 4 on DSwitch2. I notice that there are access list matches in DSwitch2 instead of at DSwitch1.

My Questions:

1) I thought the active vlan (which is DSwitch1) should see packet matches coming in from ASwitch3 when i shut down the SVI interface. But instead, i saw packets matches in DSwitch2. Why is it?

2) The route seem to choose DSwitch2 even when vlan 4 in DSwitch2 did not shut down. Is it because of the directed connected from ASwitch3 to DSwitch2 thus the packets choose DSwitch2?

3) But why HSRP did not worked as it should be the active switch?

I have this problem too.
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Davy Ad Thu, 03/19/2009 - 06:42

Hi Kianhong,

It is because you did not trace track the Physical Interface of DSwitches .

Try that and it supposed to work fine




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