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SVI VLAN change

I need to move a routed interface from an old switch to a new switch.  I tried this once and our phones lost communication with the UCS servers.  I know the MAC address will change but the phones are not on the SVI that changed.  Only the UCS servers are on that VLAN.  Should I send out a multicast ping from the new switch I migrate the SVI to to announce the change in MAC address?


Any Ideas?

VIP Master

Not sure what is the connection between your Phones and this SVI, give us more informaiton IP address Phones uses and the VLAN SVI IP address you changing ?


what is this UCS Server ? is that  serve  DHCP ?


clear IP arp for that IP should work when the new MAC Address in place.



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Balaji, I simply shut the interface off on the old switch and turn it on for the new switch.  The phones were not able to communicate with Call manager after this happened.  The phones are on seperate VLANs that the switch routes for.



VLAN4:        Wireless phones

VLAN14:    Closet VLAN

VLAN400:    Call Manager and other UCS services


I have migrated over 100 SVI's and this is the only issue I have run across.

Thanks for any and all help.

VLAN4: Wireless phones

VLAN14: Closet VLAN

VLAN400: Call Manager and other UCS services


The cordless phones are on VLAN 4.  The cabled phones are on VLANs like 14 with each closet having it's own VLAN.  Vlan 24 would be closet #2.  The phone servers are all on VLAN 400.

I change the SVI from one switch to the other and then some of the corded phones loose connectivity with the voice servers.

May be i am confused, these only 3 VLAN left to Migrate to new switch, Looks the Phones are very delicated i guess here, i have seen this Avayya phones, when the Gateway not reachable they fall off..


and they should come back as expected when the gateway available - only what i did was remove DHCP leases from DHCP Server at the same time when we moving SVI. so Phones will get IP and re-register back with Call Mananger.


if all VLAN Linked to voice, do all at a time to save time.



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Sorry, just want to clarify are the IP phones on a new voice VLAN / subnet after the move? 
If so, do you have option 150 configured in the DHCP scope for that VLAN? Option 150 is what allows the phones to register with a CUCM node which has the TFTP service enabled. 

Scott, the phones and the servers will stay on the same VLAN/IP address space.  The interface is only being moved to a C9500 from a C6509.  The gateway is still there exactly like it was before.  The only difference I can think of is the MAC address of the SVI changes after the move.

here is do below steps :


1. Configure new SVI on Cat 9500 (keep shutdown mode)

2. on the change windiow, shutdown SVI on Cat 6509 - clear IP arp for that Gateway IP address.

3. bring up SVI on Cat 9500 and test it.




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Balaji, thanks for the response.  I did all of that already except the clear ARP.  If the SVI is moved to a new switch there should be nothing to clear.  It is shutdown on the old 6509 and "no shut" on the 9500 so the ARP table should start to be populated as we go.

I suspect the problem is with the Cisco phones and not renewing their ARP table.  I do not know how to test this on the phones though.

I have done a test and the below seems to work.  I have the new switch SVI use the same old MAC address from the old SVI.

As soon as I do that it starts working.  If I wait for the phone to start to communicate it takes up to 10 minutes to refresh it's ARP cache.


interface Vlan444
description Voice-Test
mac-address xxxx.yyyy.zzzz
ip address


I found in the Cisco UCS Design Guide it states "The default ARP cache lifetime for Microsoft Windows is 2 minutes; for Linux, the default lifetime is 30 seconds; and for Cisco IP phones, the default lifetime is 40 minutes."



I guess maybe do a broadcast ping to notify them of the change would work.

that is the end device arp time out on layer 3 switch.



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