"Waters, Kivas (UK72)" makes an observation I was just wondering about the other day, while I was designing a scenario, and also muttering about the unreality of the static route prohibition.
>Can anyone shed some light on the following issue? > >IGRP---------------OSPF(area 0)----OSPF(area 1) >/24's /24's + /32's /24's + /32's > >Reading all of the groupstudy emails concerning the mechanisms to enable an >IGRP domain to see all routes within an OSPF domain, it seems that there are >a number of ways to do this. Summarising the OSPF routes for example the >OSPF /32 loopbacks into say a /24 network can be achieved using the OSPF >"area range" or "summary address" commands. When it comes to loopbacks for >example, it appears that keeping all OSPF domain loopbacks out of area 0 and >then using the "area range " command is the most obvious and easiest method >of summarising the /32 networks into an IGRP comprehendable /24 network. On >the other hand, assuming that enough address space is available, creating >another loopback, redistributing connected and using the "summary address" >command will also work. > >The question I have is this: if we are not permitted to manually configure >any static routes and we then decide to use the OSPF "area range" command, >then the Cisco IOS does not by default create a route to null0 to catch all >invalid packets destined for the summary address. Is it not MORE correct to >use the OSPF "summary address" command and have the IOS generate the route >to null0 thereby helping prevent routing loops and black holes. > >What will the proctors accept? Any idea's? > >regards > >Ki While it certainly won't reflect the real world, you certainly could put in access lists that blocked access to the undefined subnets, and/or distribute lists blocking propagation of the summary. Truly ugly. On the other hand, I had a graduate computer science professor, who, when I begged for more time on a programming project, asked to see what I had done so far. He was shocked at the size of my code...and then began to laugh that it wa full of comments, error checking, etc. He said "this is college, you don't need to put in all this stuff." I left thinking that if I learned to program HIS way, I'd soon be fired. Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=29928&t=29928 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
