Enable DNS Lookup on the Cisco PIXASA

KB ID 0000029 

Problem

You need the ASA to be able to resolve external hostname’s.

Note: You need at least version 8.2(2) before you can use a DNS name in an access-list.

Solution

Note: In this example I’m using 122.122.122.199 and 122.122.122.198 (yes, they cannot exist!) as the external DNS addresses, substitute your own.</p?

1. Whilst in enable mode > enter configure terminal mode, then enable DNS Lookups.

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CiscoASA#conf terminal
CiscoASA(config)# dns domain-lookup outside

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2. Then specify the external DNS Servers (Change IP addresses appropriately).

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CiscoASA(config)# dns server-group DefaultDNS
CiscoASA(config-dns-server-group)# name-server 122.122.122.199
CiscoASA(config-dns-server-group)# name-server 122.122.122.198
CiscoASA(config-dns-server-group)# exit

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3. Test it by pinging a name/URL.

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CiscoASA(config)# ping www.petenetlive.com
Type escape sequence to abort.
Sending 5, 100-byte ICMP Echos to 123.123.123.123, timeout is 2 seconds:
!!!!!
Success rate is 100 percent (5/5), round-trip min/avg/max = 70/84/110 ms
CiscoASA(config)#

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