Branch router -WAAS and DNS

[carl_townshend]

Hi All

We are looking at relocating as many services as possible to a centralized model, this means more dependency on the WAN, we will be having central DNS resolution and also CIFS file shares over the WAN etc. The WAN will be MPLS and Internet Backup.

My question is, can you do any DNS caching on an ISR router?

How effective will WAAS be for CIFS file shares over the WAN?

Many thanks

Carl

[Georg Pauwen]

Hello,

regarding the DNS caching, you can configure:

Router(config)#ip dns view default
Router(cfg-dns-view)#dns forwarding timeout 1
Router(cfg-dns-view)#dns forwarding retry 1
Router(cfg-dns-view)#exit
Router(config)# ip domain-lookup
Router(config)#ip domain retry 1
Router(config)#ip domain timeout 1
Router(config)#ip name-server 192.168.1.1
Router(config)#ip name-server 8.8.8.8
Router(config)#ip name-server 8.8.4.4

Which should result in:

Router#sh ip dns view
DNS View default parameters:
Logging is off
DNS Resolver settings:
Domain lookup is enabled
Default domain name:
Domain search list:
Lookup timeout: 1 seconds
Lookup retries: 1
Domain name-servers:
192.168.1.1
8.8.8.8
8.8.4.4
DNS Server settings:
Forwarding of queries is enabled
Forwarder timeout: 1 seconds
Forwarder retries: 1
Forwarder addresses:

192.168.1.1 is your local DNS server, if that is unavailable, the Google DNS servers will be queried...

[carl_townshend]

Hi

I believe with the above we can do split DNS?

So we can send all our company DNS requests to an internal server and everything else to a public server?

Also on the branch router, when we provide DHCP to the clients, I am guessing we will put the router IP in as the DNS server and the router will then forward them on as configured above?

Cheers

[Joseph W. Doherty]

"How effective will WAAS be for CIFS file shares over the WAN?"

From none to very, very effective (as in local LAN like performance). For an example, of the former, pulling a file that hasn't be accessed yet and which cannot be compressed (like something encrypted or perhaps an image). For an example of the latter, some simple text file that someone else recently already downloaded.