Cisco WS-C3750X-24T-S DHCP Question

[ALIAOF_]

Is there an official document that discusses how many DHCP leases it can support?  So for example if I setup something like this:

VLAN10

10.10.10.0/23

255.255.254.0

10.10.10.0 - 10.10.11.255

--------------------------------

VLAN 20

10.10.16.0/21

255.255.248.0

10.10.16.0 - 10.10.23.255

----------------------------------

VLAN 30

10.10.24.0/22

255.255.252.0

10.10.24.0 - 10.10.27.255

Will I run into any limitations of switch only handing out so many DHCP leases?  I recall doing it on 2960XR's and didn't really run into any issues and it has been a while so trying to confirm.  I am pretty sure it depends on the number of MAC's it can support but would like to validate.  Thank you.

[balaji.bandi · Accepted solution]

I do not see any Limitation as per i know. as you rightly said, make sure it can hold that many MAC Address in the Switch.

https://www.cisco.com/c/en/us/td/docs/switches/lan/catalyst3750x_3560x/software/release/12-2_53_se/configuration/guide/3750xscg/swdhcp82.html#56126

Why not have dedicated DHCP Server (most of them Linux based free and easy to setup on any old PC).

Look at the MAC Address limitation :

https://www.cisco.com/c/en/us/products/collateral/switches/catalyst-3560-x-series-switches/data_sheet_c78-584733.html

[ALIAOF_]

Thank you.  Yes that is the plan.  But this is a temporary solution that I need to put in place urgently.

[balaji.bandi]

yes you can do, but advise keep Monitor resources.

[Joseph W. Doherty]

"I am pretty sure it depends on the number of MAC's it can support but would like to validate."

I'm not so sure number of MACs that can be supported (such as noted in Table 10 in Balaji's reference) would apply.

What I suspect would apply is available/free RAM, also possibly including how it's currently allocated (i.e. size of free blocks).  As free RAM can vary much (including what size blocks are available), based on multiple factors (more so if you're using the switch's L3 features), large DHCP lease tables might deplete it to such an extent, even before free RAM is exhausted, that device operation might be impacted.

I'm unaware of other documented DHCP limitations.