To the original question -- There are a few ways off hand you could filter this prefix
1) area filter-list <-- OSPF inter-area filtering 2) area range no-advertise <-- OSPF summarization done for inter-area routes 3) run two processes and redistribute, filtering during redistribution like you did If you were allowed to touch the routers, you could also look at OSPF distribute-list. If you were allowed to change the topology and get a bit more crazy you could look at OSPF summary-address command as well. This command is for summarization of external redistributed routes and also has the not-advertise option available. To do that though, the route you want unreachable on the inside would have to be redistributed into OSPF in the first place. On Wed, Apr 10, 2013 at 4:59 PM, Joe Astorino <[email protected]>wrote: > Yes, the prefix-list is one of those few commands where the meaning > actually changes depending on syntax. If you says 0.0.0.0/0 you are > saying match EXACTLY the default route and only the default route. If you > say 0.0.0.0/0 le 32 you are saying "match any prefix with any mask" > > Another example > > !THIS MATCHES ONLY THE SINGLE PREFIX 192.168.10.0/24 > ip prefix-list joe permit 192.168.10.0/24 > > > ip prefix-list foo permit 192.168.10.0/24 le 28 > > This would match any prefix where the first 3 octets are 192.168.10 and > where the mask is /28 or less so...some examples of what this would match > (and many others) > > - 192.168.10.0/24 > - 192.168.10.0/25 > - 192.168.10.0/26 > - 192.168.10.0/27 > - 192.168.10.0/28 > - 192.168.10.128/25 > - 192.168.10.64/26 > - 192.168.10.128/26 > - 192.168.10.192/26 > - 192.168.10.48/28 > > Essentially, 192.168.10.x where the mask is <= /28 > > > On Wed, Apr 10, 2013 at 3:46 AM, Marta Sokolowska < > [email protected]> wrote: > >> >> 2013/4/10 Mike Rojas <[email protected]> >> >> Till yesterday I started to stay and try things out and continue with the >>> labs. It work, I just dont understand why you have to put the "le 32". >>> >> >> [...] >> >> If you will not specify "le 32", OSPF will look for the exact match, i.e. >> prefix 0.0.0.0/0, which means "default route" - and in this lab you have >> to match "any", not "default route" (you want to deny 2.2.2.2 and permit >> all other routes). >> >> There's a nice article about prefix-lists: >> http://packetlife.net/blog/2010/feb/1/understanding-ip-prefix-lists/ >> >> Hope it helps :-) >> >> -- >> >> Marta SokoĊowska. >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> Are you a CCNP or CCIE and looking for a job? Check out >> www.PlatinumPlacement.com >> > > > > -- > Regards, > > Joe Astorino > CCIE #24347 > http://astorinonetworks.com > > "He not busy being born is busy dying" - Dylan > -- Regards, Joe Astorino CCIE #24347 http://astorinonetworks.com "He not busy being born is busy dying" - Dylan
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com Are you a CCNP or CCIE and looking for a job? Check out www.PlatinumPlacement.com
