What does the "show ip route x.x.x.x" command output mean

[ahintzsche]

Hello

I am sorry, I feel like this is a very basic question. But we have a somewhat confusing scenario and when I do a show ip route command, it doesn't clear things up. So I just wanted to get an understanding what it means.

For example:

SWI001#sh ip route 10.9.39.12
Routing entry for 10.9.39.12/30
  Known via "connected", distance 0, metric 0 (connected, via interface)
  Redistributing via eigrp 39, eigrp 1, eigrp 2
  Advertised by eigrp 39
  Routing Descriptor Blocks:
  * directly connected, via Vlan120
      Route metric is 0, traffic share count is 1

In this example - what does the "advertised by eigrp 39" and the "Redistributing via eigrp 39, eigrp 1, eigrp 2" mean? (looking at the configuration for example the network command for this network is under eigrp 1 and eigrp 2, but not eigrp 39; it shouldn't actually redistribute into any of the Eigrp AS, and especially why would it redistribute into the AS where the network command is or is that default behaviour?)

Thanks

[Julio E. Moisa]

Hi

Show ip route is a command line to verify if a network/host is included on the routing table, in few words it tells you if the router knows how to reach the specific network/host. 

In your output, the IP address 10.9.39.12 is part of the network 10.9.39.12/30 and it is configured under the interface vlan 120, and this network is being redistributed into EIGRP and advertised through EIGRP 39. You could have EIGRP 1 and 2 being redistributed into EIGRP 39

The following link could be useful: https://keepingitclassless.net/2011/07/the-anatomy-of-show-ip-route/

Hope it is useful

:-)