Switched Virtual Interface question

[gatecrash]

Hello,

With regards to the below config, the int fa0/2 is assigned to interface vlan 2 (191.168.2.1). So if I plug in a computer into int fa0/2, will I get an IP assigned to my computer (in the range of 192.168.2.2 - 254) if my computer is set to obtain IP via DHCP? Or do i have to manually assign the IP myself on the computer? In my previous company this was done automatically which I'm not sure how.

.Define the VLANs
To create a VLAN named Desktop, run the following commands in privileged mode,

conf t
vlan 2
name Desktop
exit

2. Add the switch ports to previusly created VLANs
Exp: Fa0/2 to Desktop VLAN

conf t
int fa0/2
switchport mode access
switchport access vlan 2
exit

3.Create a Layer 3 (SVI) interface for eatch VLAN

conf t
interface vlan 2
ip address 192.168.2.1 255.255.255.0
no shutdown
exit

3. For Internet access, add a default route to the routing table

conf t
ip route 0.0.0.0 0.0.0.0 192.168.xx.xx

[Jon Marshall]

It will get an IP automatically if you have a DHCP server.

If you do and it is on vlan 2 as well then you don't need to do anything assuming you have setup the pool for 192.168.2.0/24.

If you do but it is on a different vlan then under the SVI for vlan 2 you need to add "ip helper-address <address of DHCP server>".

If you don't have a DHCP server you can either setup the router to hand out IPs or  you can just manually assign the IP.

Jon

[Joseph W. Doherty]

To expand a bit on Jon's answer, most hosts can work with a statically defined IP or a DHCP provided IP.  The host needs to be configured to use DHCP.  Many, but not all, hosts default to using DHCP.  When a host is configured to use DHCP, Jon describes the critical things that need to be configured for it to work.

PS:

Seeing:

3. For Internet access, add a default route to the routing table

conf t
ip route 0.0.0.0 0.0.0.0 192.168.xx.xx

If you're unfamiliar with setting up a DHCP environment, are you okay on all that's usually needed to provide internal hosts Internet access?  Reason I ask, "professional" grade network equipment usually requires much more configuration effort than "consumer" grade network equipment, and there's much that can trip you up setting up Internet access.

[gatecrash]

Hi Jon,

If the DHCP server is on say vlan 100 and I issue the ip helper-address command on SVI for vlan 2, who is making the decision here to assign a 192.168.2.0/24 ip to my computer? The switch or the DHCP server?

[Jon Marshall · Accepted solution]

Assuming a separate physical server for DHCP it is the server that is responsible for assigning the IP, the switch merely forwards the requests and responses between the client and the server.

Only if the DHCP pool was on the switch would it be responsible for assigning the IPs.

Jon