I am trying to get to the bottom of ODR over CDP. I understand that ODR utilizes IP_Prifix TLV in CDP to send and receive routers' connected networks. I also understand that this TLV is not populated by default.
Does some one know how the hub router informs the spokes to start sending this information when the 'router odr' command is configured?
Thanks for your quick reply. I wasn't clear, probably. All this I understand. What I am trying to understand is what is going on behind the scenes. For example: Does the ODR router send a CDP message to the neighbors with a default route in the IP_PREFIX TLV, which consequently triggers the spokes to send their prefixes?
Or, do the spokes send their prefixes to all neighbors all the times, but when you enable 'router odr' on the hub router, it does not ignore these TLVs?
In general, I would like to understand how CDP in ODR environment differs from the regular CDP behavior (because clearly there is a difference).
Correct. Spoke routers are advertising their connected routes via CDP all the time. This can be seen via the "show cdp nei detail" command.
When the ODR routing process is configured, this CDP info is inserted into the routing table.
In IOS version later than 12.0, ODR also has the capability of advertising a default route to the spokes router. Prior to this, a static default route had to be configured on each spoke.
Cabling-Design.com Forums website is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.