When specifying the summary address, you need to use the network address of the summarization
The address you specified is within the summary, its just not the network address. Appling the mask against your address : 00100000=32 11000000=192 --------- 00xxxxxx=0 Remember 1's we care about, 0's we don't. Now for the network, we set the don't care about bits to 0, (and for the broadcast they are all 1's) This leads to: 00->000000 = 0 Your summary is 137.20.1.0 255.255.255.192 This gives a range of address's from 137.20.1.0-137.20.1.63 (network-broadcast) Soo..... Area 11 range 137.20.1.0 255.255.255.192 would be the most exact match that you could advertise Thanks Larry -----Original Message----- From: Michael Witte [mailto:[EMAIL PROTECTED]] Sent: Saturday, May 18, 2002 7:27 PM To: [EMAIL PROTECTED] Subject: OSPF inter-area summarization [7:44465] I am trying to do a lab that needs a inter-area ospf summary address configured I have two loopbacks 137.20.1.17/28 and 137.20.1.33/28. These are then of course on networks 137.20.1.16 and 137.20.1.32. Taking the last octet of the subnets into binary we have: 16= 00010000 32= 00100000 Acording to Doyle and everything else I have read I should be able to summarize by masking the first two bits. I should be able to use: area 11 range 137.20.1.32 255.255.255.192. I am not able to and the router says I have a invalid address/mask. Furthermore the solution to the lab uses "area 11 range 137.20.1.0 255.255.255.0" which creates a summary address to all addresses of 137.20.1.X. What am I missing. This does work and I am able to ping the loopbacks but the math doesn't work for me. I should be able to summarize the 16 and 32 subnets. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=44480&t=44465 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
