- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 11:05 AM - edited 03-07-2019 06:33 AM
Hi All,
I have question about EIGRP route summarization
Router 1 has following Loopback IPs
10.2.2.1
10.2.3.1
10.2.4.1
10.2.5.1
10.2.6.1
10.2.7.1
10.2.8.1
10.2.9.1
R1 is EIGRP nei to R2
To advertise the summary route I do this under R1 serial interface
Ip summart-address eigrp 100 10.2.0.0 255.255.248.0
As IP address in EIGRP the first IP always start with 0.0 that’s why I choose 10.2.0.0
Subnet mask I choose is 255.255.248.0 is this correct?
Now when I do s hip route on R2 it still shows following 2 IPs
10.2.8.0
10.2.9.0
So these two are not included under summary address any reason?
Thanks
Mahesh
Solved! Go to Solution.
- Labels:
-
Other Switching
Accepted Solutions

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 11:16 AM
10.2.0.0 255.255.248.0 means 10.2.0.1 to 10.2.7.254--- this doesn't include 10.2.8.0 and 10.2.9.0.
to include 2.8 and 2.9, you have to choose a bigger mask 255.255.240.0 this will cover 10.2.0.1 to 10.2.15.254

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 11:17 AM
Mahesh,
I show your summary address as:
10.2.2.0 255.255.240.0
10.2.0.0 255.255.240.0
HTH,
John
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 12:03 PM
Hi John,
Your summary also includes networks 10,11,12,13,14 and 15.
therefore, Mahesh you would need to block, "10,11,12,13,14, and 15" and do not forget to deny network 0 and 1 as well via ACL if you want to.
thanks
Rizwan Rafeek
Message was edited by: Rizwan Mohamed

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 11:16 AM
10.2.0.0 255.255.248.0 means 10.2.0.1 to 10.2.7.254--- this doesn't include 10.2.8.0 and 10.2.9.0.
to include 2.8 and 2.9, you have to choose a bigger mask 255.255.240.0 this will cover 10.2.0.1 to 10.2.15.254

- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 11:17 AM
Mahesh,
I show your summary address as:
10.2.2.0 255.255.240.0
10.2.0.0 255.255.240.0
HTH,
John
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 12:03 PM
Hi John,
Your summary also includes networks 10,11,12,13,14 and 15.
therefore, Mahesh you would need to block, "10,11,12,13,14, and 15" and do not forget to deny network 0 and 1 as well via ACL if you want to.
thanks
Rizwan Rafeek
Message was edited by: Rizwan Mohamed
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 05:56 PM
Hi all,
It is working fine now
i used summary address 10.2.0.0 255.25.240.
Thanks everyone for their help
Thanks
MAhesh
- Mark as New
- Bookmark
- Subscribe
- Mute
- Subscribe to RSS Feed
- Permalink
- Report Inappropriate Content
05-07-2012 12:35 PM
Hi John,
Yes the subnet mask is 255.255.240.0 i got this by doing binary method
Will try this in my config and will let you know
Thanks
Mahesh
