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New Member

vlans and DHCP

Guys i guess its pretty basic stuff and i am not 100% sure how ot do it :-)

I have one /24 address and i have 3750 swicth and a ASA firewall. I need to configure DHCP as well choose IP for firewall inside interface as well for LAN.

I am thinking to do th follwoing and plz correct me guide me if i am wrong

ASA inside interface will be conect to 3750 so i will give to ASA interface......will create vlan say vlan 10 on swicth and will config vlan 10 ip as and will config DHCP scope on 3750 and will assign all other interfaces to vlan 10 (so that any one who connects to the interface gets vlan 10 IP from scope)

now is it right i will exclude the addresses. One thing i am not sure what shd be the default router ip and shd i give ip helper address under vlan 10??? i am sort of confuse am i at right track or not

thanks as always guys

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vlans and DHCP

If the 3750 is going to do the inter-vlan routing, don't forget to turn on routing on the switch:

S1(cofnig)#ip routing

Set the default-router in the dhcp pool to the switch's IP address of and then on the switch set the gateway of last resort to the ASA's IP address:

S1(config)#ip route

You don't need an IP-helper in this case because the packet arrives on a switched-port and the switch is the DHCP server.

New Member

Re: vlans and DHCP

Why would I need routing on switch .....i will add default gateway to Asa and that's all there in only one vlan I missing anything here

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vlans and DHCP

No, you are right. If you are only going to use 1 vlan, that will not be a problem.

Just remember to make the router a member of vlan 10.

Default-gateway will be the ASA for the clients.

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