EIGRP Auto-Summarization with Redistribution

Lessons Discussion
1

Hi I just wanted to clarify the situation with EIGRP Autosummarization and redistribution. I have come across some conflicting advice that suggests that in the case of redistribution [assuming auto-summary default is set] that either EIGRP will auto-summarize because of redistribution or the complete opposite because of redistribution … as a result I somewhat confused on this point.

2

Hi Frank,

I just played a bit with this but I don’t see anything out of the ordinary. Let’s say you have two routers, R1 and R2.

R1 has a loopback interface with 10.1.1.1/24 on it and auto-summary is enabled.

  • When you use the network command to advertise it, then it will be advertised as 10.0.0.0/8.
  • When you use the redistribute connected command, it will be advertised as 10.1.1.0/24.
No auto-summarization was performed when you use redistribution, only with the network command.

Rene