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Configure ASA 5505 as firewall

AT&T is installing a T1 line with a 3Com 5012. We have a ASA 5505 that was used with our DSL line. We have a block of 27 useable IP address. I need to configure the ASA 5505 for the T1. I need some help configuring this, as I don't know about the configuration of this firewall.

Thanks in advance
1 Solution
Here is a basic config assuming the /27 will be configured on the LAN interface of the 3Com router.

Say your /27 is x.x.x.0/27.  The router is x.x.x.1 and the ASA outside is x.x.x.2.

int vlan1
nameif inside
security-level 100
ip add
no shut

int vlan100
nameif outside
security-level 0
ip add x.x.x.2

interface Ethernet0/0                    <---the interface connected to the 3Com.
 switchport access vlan 100  
no shut

interface Ethernet0/1   <--the interface connected to your local LAN.
no shut

global (outside) 1 interface
nat (inside) 1

route outside x.x.x.1

You can enable DHCP on the ASA if desired as well:

dhcpd dns y.y.y.y z.z.z.z    <--your ISP's DNS servers
dhcpd address inside
dhcpd enable inside

You can use the other /27 IP's for static NAT statements if desired.
dboyle53169Author Commented:
Thank you for your help.

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