Steve, That's exactly what i needed to see. Thanks so much for that! For some reason i thought i needed to advertise in the exact networks as they appeared connected to the router, but it seems advertising just a router peer in that network is sufficient (which makes sense i suppose if you think about it). I guess it got this from most books or configuration examples, so i got used to it but now i realize is should treat it more like an ACL.
So when it's asked to "include the network mask" i should just go ahead with including the actual network and otherwise just be as conservative as possible to avoid including interfaces i don't want. Does this apply to all protocols? What's the best method, it does give a good quick overview of what networks are advertised when doing a sh run | i network , other then looking on the interfaces what masks they have? Alef On Jun 24, 2011, at 4:49 PM, Di Bias, Steve wrote: > Hey Alef, > > It's best to see this in action; in fact you should do some testing to help > solidify the information. The topology is simple: > > R1---R2---R4 > > R1 and R2 are connected via there FA0/0 interfaces on the 150.100.12.0/24 > subnet. R2 and R4 are connected over point-to-point frame relay serial > interfaces on the 150.100.24.0/24 network. > > We will run EIGRP on all three routers using specific, less specific, and > exact network commands on R1 and R4, and then verify what get's advertised. > > R1(config-if)#router eigrp 100 > R1(config-router)#no auto-summary > R1(config-router)#network 150.100.12.0 0.0.0.255 > > R2(config-if)#router eigrp 100 > R2(config-router)#no auto-summary > R2(config-router)#network 150.100.12.0 0.0.0.255 > R2(config-router)#network 150.100.24.0 0.0.0.255 > > R4(config)#router eigrp 100 > R4(config-router)#no auto-summary > R4(config-router)#network 150.100.24.0 0.0.0.255 > > At this point R4 should see the 150.100.12.0/24 network in it's routing table > > R4(config-fr-dlci)#do sh ip ro ei > 150.100.0.0/24 is subnetted, 2 subnets > D 150.100.12.0 [90/2172416] via 150.100.24.2, 00:00:09, Serial0/0.24 > > > Now let's advertise this out from R1 using a /32 wildcard mask > > R1(config-router)#router eigrp 100 > R1(config-router)#no network 150.100.12.0 0.0.0.255 > R1(config-router)#network 150.100.12.1 0.0.0.0 > > R2(config-fr-dlci)#router eigrp 100 > R2(config-router)#no network 150.100.12.0 0.0.0.255 > R2(config-router)#network 150.100.12.2 0.0.0.0 > > R4(config-fr-dlci)#do clear ip route * > R4(config-fr-dlci)#do sh ip route ei > 150.100.0.0/24 is subnetted, 2 subnets > D 150.100.12.0 [90/2172416] via 150.100.24.2, 00:00:01, Serial0/0.24 > > Still the same with most specific... Now let's match "everything" and we will > check out what interfaces are participating!! > > On R1 I have a bunch of networks and interfaces as you can see here > > R1(config-router)#do sh ip int br > Interface IP-Address OK? Method Status > Protocol > FastEthernet0/0 150.100.12.1 YES manual up > up > FastEthernet0/0.100 192.168.100.1 YES manual up > up > FastEthernet0/0.200 192.168.200.1 YES manual up > up > FastEthernet0/0.300 192.168.255.1 YES manual up > up > FastEthernet0/1 unassigned YES manual up > up > FastEthernet0/1.146 10.0.146.11 YES manual up > up > FastEthernet0/1.1256 9.9.156.11 YES manual up > up > Loopback0 1.1.1.1 YES manual up > up > > Let's advertise them all with on command > > R1(config)#router eigrp 100 > R1(config-router)#no network 150.100.12.1 0.0.0.0 > R1(config-router)#network 0.0.0.0 0.0.0.0 > > All of these interfaces should be participating now and R4 should see of > these routes: > > R1(config-router)#do sh ip ei inter > IP-EIGRP interfaces for process 100 > Xmit Queue Mean Pacing Time Multicast Pending > Interface Peers Un/Reliable SRTT Un/Reliable Flow Timer Routes > Fa0/0 1 0/0 2 0/1 50 0 > Fa0/0.100 0 0/0 0 0/1 0 0 > Fa0/0.200 0 0/0 0 0/1 0 0 > Fa0/0.300 0 0/0 0 0/1 0 0 > Fa0/1.146 0 0/0 0 0/1 0 0 > Fa0/1.1256 0 0/0 0 0/1 0 0 > Lo0 0 0/0 0 0/1 0 0 > > > R4(config-router)#do clear ip route * > R4(config-router)#do sh ip route ei > D 1.0.0.0/8 [90/2300416] via 150.100.24.2, 00:00:03, Serial0/0.24 > D 192.168.200.0/24 [90/2174976] via 150.100.24.2, 00:00:03, Serial0/0.24 > 10.0.0.0/24 is subnetted, 2 subnets > D 10.0.146.0 [90/2174976] via 150.100.24.2, 00:00:03, Serial0/0.24 > D 192.168.255.0/24 [90/2174976] via 150.100.24.2, 00:00:03, Serial0/0.24 > D 192.168.100.0/24 [90/2174976] via 150.100.24.2, 00:00:03, Serial0/0.24 > 150.100.0.0/24 is subnetted, 2 subnets > D 150.100.12.0 [90/2172416] via 150.100.24.2, 00:00:03, Serial0/0.24 > > > > Test this in your lab when you have time! Remember we are just "matching" > interfaces here! > > > Thank you, > > Steve Di Bias > Network Engineer - Information Systems > Valley Health System - Las Vegas > Office - 702- 369-7594 > Cell - 702-241-1801 > [email protected] > > -----Original Message----- > From: Alef [mailto:[email protected]] > Sent: Friday, June 24, 2011 7:21 AM > To: Di Bias, Steve > Cc: [email protected] IE > Subject: Re: [OSL | CCIE_RS] vol1 27.2 why are the links in OSPF not > advertised as in EIGRP > > Hey Steve, > I have to admit i never thought of it that way (that it matches the > interface). When i advertise a network for a link i always advertise the > correct mask. > It's good to know but i will find it hard getting used to, i don't think i > will change that unless specifically told either. > > But it's good to hear the explanation behind it though. > > On Jun 24, 2011, at 2:51 PM, Di Bias, Steve wrote: > >> Hey Alef, >> >> Your subject confuses me, however the message body seems to make more sense. >> >> The thing to remember about routing protocols like EIGRP and OSPF is that >> when using your network statements you can be as vague, or as specific as >> you want to be. Remember, you're using the network command to "match" the >> interfaces you want to participate in the routing protocols which are smart >> enough to see the "actual" IP address and mask and that's what gets >> advertised out. >> >> In the real world do what you're told to do, however in the real world I use >> "exact" wildcard masks when advertising, but it's up to you. >> >> >> >> Thank you, >> >> Steve E. Di Bias >> Network Engineer - Information Systems >> Valley Health System - Las Vegas >> Office - 702- 369-7594 >> Cell - 702-241-1801 >> [email protected] >> >> -----Original Message----- >> From: [email protected] >> [mailto:[email protected]] On Behalf Of Alef >> Sent: Friday, June 24, 2011 3:37 AM >> To: [email protected] IE >> Subject: [OSL | CCIE_RS] vol1 27.2 why are the links in OSPF not advertised >> as 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 >> >> >> UHS Confidentiality Notice: This e-mail message, including any attachments, >> is for the sole use of the intended recipient (s) and may contain >> confidential and privileged information. Any unauthorized review, use, >> disclosure or distribution of this information is prohibited. If this was >> sent to you in error, please notify the sender by reply e-mail and destroy >> all copies of the original message. > > > > UHS Confidentiality Notice: This e-mail message, including any attachments, > is for the sole use of the intended recipient (s) and may contain > confidential and privileged information. Any unauthorized review, use, > disclosure or distribution of this information is prohibited. If this was > sent to you in error, please notify the sender by reply e-mail and destroy > all copies of the original message. _______________________________________________ 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
