Dear group,

I am an MSc student in Electrotechnical Engineering and I am currently researching configuration commands in Cisco IOS for my thesis.

In particular, I am interested in setting the administrative distance of a route according to the route's destination prefix. I am aware of the "distance" command in the form:

distance {ip-address {wildcard-mask}} [ip-standard-list] [ip-extended-list]

which allows one to set the administrative distance of a route (within the configuration of a particular routing protocol) according to what Cisco's documentation [1] refers to as the "source of a route". The documentation is not very clear on what this means, but my interpretation is that it refers to the neighboring router from which the route in question was received. On the other hand, the book "Cisco IOS in a nutshell" says it refers to the route's destination address; confusingly, it also describes the command's syntax as

distance distance [address mask] [access-list]

which is missing one argument relative to the version above.

Since the two interpretations contradict each other, I wonder if you could provide me an answer to any of the following questions:

(i) What is the correct syntax of the "distance" command and, in particular, what do the ip-address and wildcard-mask parameters mean;

(ii) Is there any way, using this command or another one, to set a route's administrative distance based on the route's destination prefix/address?

Thanks in advance.

Best regards,

Tiago

[1] Cisco IOS IP Command Reference, Volume 2 of 3: Routing Protocols, Release 12.2