I have a cablemodem service with css326-24g-2s+rm administrable switch and i need to connect this cablemodem to my this to share interne, and Is capable to work like DHCP this switch?
I am very sorry, but your Question is difficult to understand…
If you have a “cable modem” that is also a Router which provides Network-Services like DNS, DHCP, Firewall, Routing , etc..
Then you can use the Mikrotik css326-24g-2s+rm
BUT If you have a “cable modem” that is only a MODEM,
then you can NOT use the mikrotik css326-24g-2s+rm
To put information by @ConnyMercier in another words: CSS326 is a decent managed switch, but can not perform any of router’s tasks … so it can’t run DHCP server, it can’t route, it can’t be firewall, it can’t perform NAT … nothing.