Switching

Hello colleagues,
I have one simple question, but I not know how do it.

So, i have switch EX2200 as access switch in network, by cisco  have command ip default-gateway. 

Do have juniper analouges command or i must use set routins-options default <host>?

routing is per default enabled, even in an EX2200, so you just have to configure a static route for 0.0.0.0/0:

set routing-options static route 0.0.0.0/0 next-hop <gateway-ip>

Ok, I thought same way.
One yet question, how be with dhcp-relay? DHCP-relay needed configure on switch (by access role)?

For DHCP-Relay, could you elaborate? You want this switch to be bootp or dhcp-relay agent?

Simplified scheme in attache.
We talk about switch2. Do should i configure DHCP-relay on switch2?

Switch1 already doing DHCP Relay.. yes?

Why cascade Relay on switch2.. how about a trunk link between the Switch2 to switch1.

For instance:

PC DHCP/BOOTP => SW1 <Trunk> SW2 => DHCP SERVER

"witch1 already doing DHCP Relay.. yes?"

Yes.

"Why cascade Relay on switch2.. how about a trunk link between the Switch2 to switch1.

 For instance:

PC DHCP/BOOTP => SW1 <Trunk> SW2 => DHCP SERVER"

Such a network design, DHCP server is outside location. New switch  need for connect new users. Of course between switch1 and switch2 trunk link.

Okay, So Relay on SW2 for new users, grabs DHCP Req & points to DHCP Server IP.

SW1 which is L3 knows how to route towards DHCP server IP just does IPforwarding then.