[Enterprise SONiC] DNS Follow

Use a remote DNS (Domain Name System) server to resolve the map between IP and domain name.

Tested model & firmware version:

• Switch model name:
  DCS500 (AS7816-64X)
  DCS203 (AS7326-56X)
  DCS201 (AS5835-54X)

• Edgecore SONiC version:
  202006 ~ 202006.4
  202012.0 ~ 202012.4
  202111.0 ~ 202111.3

Restriction:

• Known issue: [SONIC-3928] after upgrading via the "sonic-installer" command, /etc/resolv.conf is reset back to default. (This issue is fixed on version 202012.4)

Procedure:

Step 1. Add nameserver ip (8.8.8.8 as example) to /etc/resolve.conf

admin@sonic:~$ sudo vi /etc/resolv.conf 
nameserver 8.8.8.8

Caution: Make sure switch IP address and connectivity works well. (refer to Management IP address) Result: - The switch resolves domain name properly.

admin@sonic:~$ ping www.google.com
PING www.google.com (216.58.200.228) 56(84) bytes of data.
64 bytes from tsa03s01-in-f228.1e100.net (216.58.200.228): icmp_seq=1 ttl=55 time=2.66 ms
64 bytes from tsa03s01-in-f228.1e100.net (216.58.200.228): icmp_seq=2 ttl=55 time=2.68 ms
64 bytes from tsa03s01-in-f228.1e100.net (216.58.200.228): icmp_seq=3 ttl=55 time=2.65 ms

--- www.google.com ping statistics ---
3 packets transmitted, 3 received, 0% packet loss, time 2002ms
rtt min/avg/max/mdev = 2.656/2.668/2.682/0.043 ms
admin@sonic:~$