Interconnecting ASA5505 with Cable modem

Your outside interface should be dhcp client

interface Vlan10

nameif outside

security-level 0

ip address dhcp setroute


Your inside interface ip address

interface Vlan20

nameif inside

security-level 100

ip address cyruslab.local


dhcp auto_config should be enabled globally

dhcpd auto_config outside



**auto-config from interface ‘outside’

**auto_config dns

autoconfig helps your asa to get the dns, wins information obtained from your isp dhcp server.



nat (inside) 1 dns

global (outside) 1 interface


Enable dns lookup

dns domain-lookup outside


Optional: Set a valid dns server on your asa

dns name-server



cyrus(config)# ping

Type escape sequence to abort.

Sending 5, 100-byte ICMP Echos to, timeout is 2 seconds:


Success rate is 100 percent (5/5), round-trip min/avg/max = 10/12/20 ms


Set ntp server

ntp server



Set timezone

clock timezone SGT 8


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s