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Download Router Configuration to a Web Browser

If you have HTTP server enabled on your router (on by default in many IOS releases, enable with ip http server), you can download the current router configuration into your web browser simply by typing in the URL http://router/exec/show/running/full. To get the startup configuration, use http://router/exec/show/startup-config/CR.

Of course, you need to authenticate to the router. By default, you can use anything as the username and the enable-password as the password, but you also use local usernames or AAA authentication. To use local usernames, configure ip http authentication local and enter username and password with the username username privilege 15 password password configuration command.

Use HTTP to Store Router Configurations on Web Server

It's been possible for a long time to use HTTP to download information from a web server to a router. In IOS release 12.3(2)T, integrated in 12.4 release, Cisco has introduced the ability to store local information (for example, router configurations) on a web server. To use this feature, configure the username and password giving you write access to the web server with:
ip http client username web-user
ip http client password secret-password
After the username and password have been configured, you can use copy running http: to copy router's configuration to a web server.
Note: on the web server, you have to configure the target virtual directory for write access (default: disabled) and allow file-system write access to the underlying physical directory for the target user.
Alternatively, you can specify the username and password in the URL using the copy running http://user:[email protected]/file syntax.
router#copy running http://student:[email protected]/router-config
Address or name of remote host []?
Destination filename [router]?
Storing http://student:[email protected]/router-config !!
4231 bytes copied in 0.864 secs (4897 bytes/sec)

Using a router as a DNS proxy server

A Cisco router running IOS release 12.3 can act as a proxy DNS server - when you configure ip dns server and ip name-server ip-address, it starts forwarding any received DNS requests to the upstream name server.

The router does not act as a recursive server, it just propagates the requests. For example, if the client asks for A record for and the upstream DNS server responds with a NS record for the .com tree, the router will not perform recursive DNS lookups to get the answer (and the resolver code in most clients will fail). The upstream DNS server has to be willing to perform recursive lookups for you.

You can use this functionality (potentially in combination with other external proxies) to set up an environment where the clients do not need to access the Internet directly.