Stuck in a situation, and need some advice.
We use OpenDNS for our DNS services. However, we want to use GoogleDNS at the end of the business day, and then revert back to OpenDNS the next morning, start of business day.
My thinking is to use time-range ACLs on port 53 to accomplish this. All clients are set to acquire DNS automatically via the DHCP (our Cisco 2600 router is also acting as DHCP).
Below are chunks from the running-config (of our test router):
ip dhcp pool DHCP
network 192.168.25.0 255.255.255.0
dns-server 220.127.116.11 18.104.22.168
ip name-server 22.214.171.124
Time Range setup
periodic weekdays 16:00 to 11:59
periodic weekdays 00:00 to 15:59
permit udp any host 126.96.36.199 eq domain time-range OpenDNS
permit udp any host 188.8.131.52 eq domain time-range GoogleDNS
deny udp any any eq domain
Assign ACL to Router interface
ip access-group Permit_Deny in
The router has the correct clock time via the configured NTP server.
We are getting inconsistent results from our client machines, as in some machines use OpenDNS, some use GoogleDNS, etc.
Any advice/guidance to get this to work is highly appreciated.