small subnet usage advantage

[knaik99]

if we have LAN site with 500 PC users then why is it better to go with two /24 subnet instead /23?

what is advantage of such subnet wrt STP ,Broadcast domain etc?

please explain

[balaji.bandi]

i would advise to go with /24 network, so you can limit the broadcast domain in to smaller. easy to diangonosis the issue if any Layer 2, rather whole network go down whole range of domain.

again it all depends on what kind of switches you are deploying here, new Cat 9K have good size and they have to handle more protection.

how big is your network (interms of switches ?)

[knaik99]

100 access switches and 2 chasis based core

[balaji.bandi]

Since  you are using RFC 1918 address space, you have each access switch have different IP address scope of /24

As per your other thread Core and access switch discussion, you want to all Layer 3 should be ion Core,

If you like to deploy and easy to diagnosis. Make different VLAN for Manangment for Switch Manangment, use different VLAN for Voice and Data and other new vlan for each service, so you now very well what IP address service what services, rather using /23 network all in one or more /23 in each vlan

[Joseph W. Doherty]

Bigger L2 domains, as I suspect you're aware, increase the risk of broadcast issues.

On IP networks, on modern equipment, they often will work just fine using a /23.  Although most would not actually use two /24s or one /23 for 500 hosts.

If you really have 500 PCs, one potential issue, you don't have much room for growth.  The larger /23 might better support any growth as all the "free" IPs are in the same pool.  Using multiple subnets, growth might run one of your /24s dry while the other still has free IPs.

With 500 users, you likely would be better planning on using more subnets to allow for growth.  E.g. three /24s or five /25s or perhaps nine /26s, etc.