Hi all,

I have a client who needs to migrate from a 3Com 100Mbps "core" switch to a new Aruba 2930F Layer 3 switch (1Gpbs).

Thus far I have installed and configured the following access layer switches (there are no "distribution switches" in the design).

2 x HP 2530G 48-port PoE switches
2 x Aruba 2930F 48-port PoE switches
1 x HP 24-Port switch non-PoE (the model escapes me right now)

1 x Aruba 2930F 24-port PoE switch (New Core switch)

All the above have 2 vlan's configured;

vlan 1 (native vlan) - 10.1.0.x
vlan 2 (voice vlan) - 10.1.1.x

Traffic for vlan 1 is untagged and traffic for vlan 2 is tagged.

I have the new core switch installed but is has not "taken up" the core switch role as yet. Currently it only has an uplink to the 3Com Core switch.

The default gateway is a Dell SonicWall -
DHCP services (for both vlan's) are provided from 2 DC's on vlan 1 -

I am looking at these next steps to complete;


  • Configure trunk ports (to carry vlan 1 & 2 traffic) on the core switch and each access switch. These are the uplinks between the core switch and the access switches.
  • Configure the Aruba core switch as the default gateway on each of the access switches. This means all traffic will go via the core first.
  • Configure the Aruba core switch to use the Dell SonicWall as its default gateway. Again, the core switch will receive all the traffic first and then forward any "external" traffic to the firewall.
  • Configure the Dell SonicWall to forward any traffic for vlan 2 to the new aruba switch... this will allow the VoIP phones to get DHCP addresses from the domain controllers on vlan 1. I have this setup already but just need to change the route on the firewall to use the new Aruba core switch's address instead of the 3Com's.

Things I'm not too sure of with the above....

Remove the the IP-helper addresses (these are the DHCP servers) from all the access switches and just have these configured on the core switch. Thus, any DHCP requests will go from the end-point to the core switch to the DHCP servers and then back again?
Changing the default gateway on the access switches from the firewall address to the core switch address. To me this is about creating a more efficient network, rather than have the firewall send traffic back and forth from all the switches, route all the traffic to the core switch and then let the core switch forward packets to the firewall as required.


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Any recommendations or advice would be appreciated.