hsrp - issue

dave dave · ‎09-09-2011

hi! recently i setup a 3560 L3 sw with hsrp wiht the following configs. Currently i only have 1x 3560 L3 switch, but aonther unit will only be in at later stage. I noticed that with this standalone 3560 switch, the vlan interface protocol is always down. It will only be up if i configure the switch port with that particular vlan and with a host connected to that port. when no host is connected to it, vlan interface protocol will always be down. Even if the host is connected to that vlan, it will take a few minutes before it's up again. Has anyone encounter this before? My understand is that even if with one switch running the vlan interfaces shd always be up. Any idea? Thanks.

interface Vlan18

description VLAN 18 Mgt

ip address 10.18.8.2 255.255.255.0

standby 1 ip 10.18.8.1

standby 1 priority 120

standby 1 preempt

!

interface Vlan19

description VLAN 19 Svr

ip address 10.18.9.2 255.255.255.0

standby 1 ip 10.18.9.1

standby 1 priority 120

standby 1 preempt

!

interface Vlan20

description VLAN 20 client

ip address 10.18.10.2 255.255.255.0

standby 1 ip 10.18.10.1

standby 1 priority 120

standby 1 preempt

Reza Sharifi · ‎09-09-2011

That is the correct behavior. If you only have an SVI without the layer-2 vlan the SVI will not come up until you create the layer-2 vlan. In order for the layer-2 vlan to come up, you need to add a physical port to that vlan.

HTH

cadet alain · ‎09-09-2011

hi,

this is a normal behaviour as for a svi to be up the vlan must exist and there must be one port in this vlan and this port must be in the connected state. the waiting time you experience is due to spanning-tree convergence.

regards.

alain.

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dave dave · ‎09-09-2011

hi! thanks, i did create the vlan using the command below. but when i do a show run i did not see the (vlan 18 name mgt 18) portion, i can only see the interface below. When i do a show vlan, vlan 18 is there. Is that normal in 3560 switch? i can see all this info in 4506 sw. Thx.

interface Vlan18

description VLAN 18 Mgt

ip address 10.18.8.2 255.255.255.0

standby 1 ip 10.18.8.1

standby 1 priority 120

standby 1 preempt

vlan 18

name mgt 18

Somasundaram Jayaraman · ‎09-09-2011

Hi,

Whether VTP is running on your device?

If VTP mode is in client then you wont see vlans in show run. If the device running VTP in Transparent then you will see.

This is because in client mode, vlan.dat file will be in server. Whereas in client, vlan.dat file is localized to a switch.

Hope this answers your questions.

Cheers

Somu

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shehinpm1 · ‎09-11-2011

Yes correct,u canot see the vlan information in sh runn unless u configure VTP server or transparent mode,then only

the SW will have the VLAN.dat in its local databse.pls note the VLAN.dat will be in flash not in NVRAM.

thx,

shehin.pm

dave dave · ‎09-11-2011

hi! does the vtp domain thing matters in this case? I've changed it to transaprent mode, and the vlan xxx command is displayed when i do a sh run.

But, when i do a show standby, it always says that active and standby router is unknown. Thanks.

Vlan19 - Group 1

State is Init (interface down)

199 state changes, last state change 20:53:09

Virtual IP address is 10.18.9.1

Active virtual MAC address is unknown

Local virtual MAC address is 0000.0c02.ac11 (v1 default)

Hello time 3 sec, hold time 10 sec

Preemption enabled

Active router is unknown

Standby router is unknown

Priority 120 (configured 120)

Group name is "hsrp-Vl19-1" (default) Vlan12 - Group 1
State is Init (interface down)
199 state changes, last state change 20:53:09
Virtual IP address is 10.18.9.1
Active virtual MAC address is unknown
Local virtual MAC address is 0000.0c02.ac11 (v1 default)
Hello time 3 sec, hold time 10 sec
Preemption enabled
Active router is unknown
Standby router is unknown
Priority 120 (configured 120)
Group name is "hsrp-Vl19-1" (default)

Aileron88 · ‎09-11-2011

This is because the the SVI is down. If the SVI interface is up in your case you will see the Active router is local and the standby router is unknown.

The VTP mode makes no difference from a functional point of view if we're just talking about HSRP, but in VTP transparent you will be able to see the vlans in the running conf, in client you will have to do a sh vlan.

Adam