Thanks Marko, Got it. I just always advertised in the networks as directly connected to the router. The part about it being an ACL though, could i ever make a mistake by just doing that, i.e. advertising the networks, how could i possibly advertise in to much if those are my directly connected interfaces? I can't have overlapping interfaces? I know understand that you can also just advertise in a /32 interface address instead, but which method is better ?
Alef On Jun 24, 2011, at 4:49 PM, Marko Milivojevic wrote: > Think of a network statement as of an access-list. Whatever interface > address matches, the protocol will be enabled on it. Enabled means - > protocol related data will be sent and received and the network > address, regardless of the mask configured on the interface will be > advertised. For example: > > Interface FastEthernet0/0 > ip address 10.0.0.1 255.0.0.0 > ! > router ospf 1 > network 10.0.0.0 0.0.0.3 area 0 > ! > > Obviously, there is a "mismatch" between the mask used on the > interface and the wildcard mask in the network statement, but it > doesn't matter. Interface IP address matches and that means, OSPF 1, > Area 0 will be enabled on it. It also means that 10.0.0.0/8 will be > advertised into OSPF as an internal route in area 0. > > -- > Marko Milivojevic - CCIE #18427 > Senior Technical Instructor - IPexpert > > FREE CCIE training: http://bit.ly/vLecture > > Mailto: [email protected] > Telephone: +1.810.326.1444 > Web: http://www.ipexpert.com/ > > On Fri, Jun 24, 2011 at 10:24, Alef <[email protected]> wrote: >> So you're saying when we have network >> >> a /27 and network b /26 and network c /24 >> >> it would be ok to just advertise in the 32 host routes /p2p links and the >> networks would still be known without explicitly advertising them in (As in >> say ospf?) >> On Jun 24, 2011, at 1:37 PM, Matlock, Kenneth L wrote: >> >>> Maybe I misinterpreted the question, but het, that's never stopped me >>> before :) >>> >>> The 'network' statement on the routing protocol doesn't necessarily specify >>> the EXACT netblock to announce. >>> >>> The 'network' statement merely gives you what range of netblocks to >>> announce, or establish neighbor adjacencies on. So a 'network 150.50.25.2' >>> statement says to establish neighbor adjacencies with anything 150.50.0.0 >>> range (150.x.x.x is in the class 'B' range, so by default has a /16 netmask >>> unless you tell it different), and announce any connected interfaces that >>> are in the 150.50.0.0/16 range. >>> >>> Personally in production I purposely restrict down the network statements >>> to the smallest possible, but that's only so I know it's a 100% conscious >>> decision that I'm injecting a route into the production route tables :) >>> >>> Make sense? >>> Ken >>> >>> ________________________________ >>> >>> From: [email protected] on behalf of Alef >>> Sent: Fri 6/24/2011 4:36 AM >>> To: [email protected] IE >>> Subject: [OSL | CCIE_RS] vol1 27.2 why are the links in OSPF not >>> advertisedas in EIGRP >>> >>> >>> >>> In this task, the the assignment seems the same (apart from the configure >>> the network statements to include the network mask) but the link is >>> advertised as: >>> >>> network 150.50.25.2 >>> >>> and not as 150.50.25.0 0.0.0.3 or 0.0.0.1 >>> >>> in 27.1 eigrp does advertise as a /30, 0.0.0.3 >>> >>> is it not best practice to always advertise the networks into any routing >>> protocol properly ? >>> >>> Alef >>> _______________________________________________ >>> 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 >>> >>> >>> *** Exempla Confidentiality Notice *** The information contained in this >>> message may be privileged and confidential and protected from disclosure. >>> If the reader of this message is not the intended recipient, or an employee >>> or agent responsible for delivering this message to the intended recipient, >>> you are hereby notified that any other dissemination, distribution or >>> copying of this communication is strictly prohibited. If you have received >>> this communication in error, please notify me immediately by replying to >>> the message and deleting it from your computer. Thank you. *** Exempla >>> Confidentiality Notice *** >>> >> >> _______________________________________________ >> 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 >> _______________________________________________ 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
