Matt, Excellent explanation of something often very hard to explain!
>It is designed to prevent a routing loop which could occur if you inject a >supernet to which all included routes arent accounted for I beleive. For >example > >r1 -----------r2-----------r3 >R1 has ip addresses 10.1.1.0 - 10.1.9.0 and neighbors with r2 in area 2 > >R2 enters an area 2 range 10.1.0.0 255.255.240.0 (summarizing 10.1.1.0 - >10.1.15.0) and neighbors with r3 in area 0 > >R3 issues default information originate so that r2 has a 0/0 route pointing >to r3 > >So...now R3 pings an address at 10.1.10.0 which doesnt really exist. Since >it falls within the summary r3 sends the packet to R2. R2 doesnt have a >route for the network 10.1.10.0 so it uses the 0/0 route back to >R3...and...boom..routing loop. Now you can see what the null route would >do. By creating this than it would bit bucket all routes not expicity in >the routing table thus preventing the loops. > >Thats my understanding at any rate. > >Experts please advise if I am mistaken > >Luck to All >Matt Smith > >----- Original Message ----- >From: "Jaspreet Bhatia" >To: >Sent: Wednesday, November 28, 2001 7:51 PM >Subject: OSPF Summarization > > >> While doing OSPF summarization on an ABR with the area range command , >what >> is the function of including a static route pointing to the NULL interface >? Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=27639&t=27639 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
