Stacking 4500's

[Jonathancert_2]

Need a second pair of eyes on a task.  One of my floor closet's 4510R-E is full and I plan on trunking another 4507R to the main access switch.  The reason I am leaning toward trunking the 10G uplinks is to utilize the remaining IP's on the SVI's.  The topology has all the 4510R-E having individual uplinks to two distro 6509-E's for failover.  Don't think this is a complicated endeavor but wanted to run it by the community.

Jonathan,

[Jon Marshall]

Jonathan

Not clear what you mean by utilise the IPs on the SVIs ? Is the 4510R-E switch routing in the access-layer ?

Jon

[Jonathancert_2]

The 4510's are in transparent mode and doing layer 3 routing for VOIP and data.  They have layer 2 trunks to the the 6509's.

[Jon Marshall]

Jonathan

Apologies but you have lost me

They are routing for some vlans but then connected to the 6500s with L2 trunks ?

What do you mean by transparent ?

If i understand correctly though you want to use the L3 SVIs on the 4510R-E for any new devices connected to the 4507 ?  If so then yes, it would be easiest to simply connect the 4507 to the 4510R-E with a trunk which allowed those vlans.

Jon

[Jonathancert_2]

Sorry to confuse you.  Just wanted to clarify that all my network switches are in VTP transparent mode.  I have no server or client switches.  The 4500 are at my access layer physically connect all the necessary devices (VOIP, workstations, printers, etc.).  I have separate layer 3 SVI's for the VLANs;

example: (4510_SW1)

interface Vlan200

des VOIP clients

ip address 192.168.21.1 255.255.255.0

ip helper-address 172.16.32.33

interface GigabitEthernet1/9

description Room 3040

switchport access vlan 51

switchport mode access

switchport voice vlan 200

When I uplink 4510_SW2, just want it to be able to use the available IP's from vlan 51 and 200.

Jonathan,

[Jon Marshall]

From a config and deployment view, yes connecting the 4507 to the 4510 with a L2 trunk is the easiest thing to do. Just be aware though, as mentioned in previous post, that the 4507 could lose connectivity to the network if the 4510 goes down.

This is the main drawback to daisy chaining switches this way.

Jon

[Jon Marshall]

Jonathan

Just a thought but do you need to use the same vlans on the new switch ? And do you have spare fibres to the 6500 ?

Because if so you may want to consider connecting the new 4507 directly to the 6500s and then perhaps spreading the load of connections between the switches. This would give you more redundancy on that floor.

The only downside would be if there was a lot of communication between the clients on the 4510 and the clients on the 4507 which would then have to go back via the 6500s.

Jon

[Jonathancert_2]

It not the VLANs that are the main problem, it's the IP addresses.  I would have to request new subnets and that is long procedure.  Not to mention have to coordinate with the server team for DHCP and firewall inclusion.  I think the 10G uplink can handle the chatter between 4500's.  Utilization is still less than 10% on the fully populated 4510R-E and I have 512Mbps of RAM.

[Jon Marshall · Accepted solution]

Co-ordinating with the firewall team, ahh that brings back memories, not all of them pleasant

Yes, just connect them up with a trunk, makes your life a lot easier.

Jon