I'm currently studdying for my CCNP BSCI certification Exam, I use Cisco press certification guide and also other's web documentation.
I would like to have some explanation about MD5 EIGRP authentification.
I had understand we can define more then one key to authenticate to prevent someone would be able to guess the encryption key. In the "accept-lifetime" and "send-lifetime" command we can define the start time and end time of use... but duration parameter how can be able to use this parameter... and make sure the other router have the same syncronisation time... Exemple : if I set send-lifetime 20 june 2009 at 0:00:00 to 30 june 2009 at 0:00:00 and a duration of 3600 seconds. And on the other router I set accept-lifetime 20 june 2009 at 0:00:00 to 30 june 2009 at 1:00:00 and a duration of 3720 seconds. How those router are be able to syncronise there usage of MD5 key.... Example after a reload or power rest of one of them ?
In debug command "debug eigrp packets" when it show received packet with MD5 authetification key id = 1 is the key ID speciffied here is the key id 1 of tghe local or remote device ? I had understand the local and remote device have not to use the same key ID but they have to use the same key in the same order. Example R1 could use key id 1 to 10 and R2 use key ID 11 to 20 but key ID 1 should have the same key string as key id 11, and key ID 2 should have the same key string as key id 12, and so on...
in the following explanation :
"Although EIGRP is a classless routing protocol, it has classful behavior by default, such as having automatic summarization on by default. When you configure the hub router to send a default route to the remote router, ensure that the ip classless command is issued on the remote router. By default, the ip classless command is enabled in all Cisco IOS images that support the EIGRP stub routing feature."
what is the usage on the ip classless command ?
Thanks for your help !