Ahhh.. I was wondering if we were talking at cross purposes. It seemed like a very strange position for you to be taking otherwise!
All is clear now. JMcL The Long and Winding Road wrote: > > hhhhmmmmmm....................... > > OK, we'll chalk this one off as a failure to communicate. > > the original post called for > > "similar to ccbootcamp lab 5 , but how to summary those serial > to other > protocol ? > area 0 range 172.16.1.0 255.255.255.0 area not working on ABR > either " > > which I took to mean summarizing area 0 routes to other area 0 > routers and > ultimately into an external protocol. which of course cannot be > done. > > obviously, you are talking about summarizing area 0 routes into > a non-zero > area, which of course, does work just fine. > > > -- > > www.chuckslongroad.info > > > > > ""Jenny McLeod"" wrote in message > news:200210290538.FAA14601@;groupstudy.com... > > The Long and Winding Road wrote: > > > > > > ""Jenny McLeod"" wrote in message > > > news:200210280429.EAA24675@;groupstudy.com... > > > > The Long and Winding Road wrote: > > > > [snipped] > > > > > > area 0 range 172.16.1.0 255.255.255.0 area not > working on > > > ABR > > > > > either > > > > > > > > > > > > > > > > CL: well, area 0 range is an illegal command. you may > be > > > able > > > > > to enter it, > > > > > but it does nothing. the area range command is design to > > > > > summarize non > > > > > backbone routes into the backbone. if you think aout it, > > > there > > > > > is probably > > > > > not a real good reaso for backbone routes to be > summarized > > > > > > > > > > > > > > JMcL: Since when?? > > > > I use the area 0 range blah blah command (without the > "area" > > > at the end, > > > if > > > > that was supposed to be part of the command above), and it > > > certainly > > > doesn't > > > > do nothing. As far as I've seen, it works in exactly the > > > same way as area > > > > anything else range blah blah. > > > > > > > > > All right, Miss Smarty Pants. I don't know what IOS versions > > > you use / have > > > been using, but I have been through this song and dance with > > > OSPF area 0 > > > summarization, or lack thereof for a while now. I have yet > to > > > see it work. > > > > > > Seriously, Jen, you know I respect your wisdom and value > your > > > advice. I am > > > absolutely certain that I have never successfuly summarized > > > area 0 routes > > > over a couple of years of lab rat living. The following is > from > > > my current > > > study pod, and the IOS version is 12.1.5T10. > > > > > > First, router 1 configurations. There are a number of > > > loopbacks,containing > > > the route addresses in question. > > > > > JMcL: Are any of the relevant routes being redistributed from > RIP, or are > > the relevant bits pure OSPF? > > > > > router ospf 123 > > > log-adjacency-changes > > > area 0 range 100.100.0.0 255.255.240.0 > > > redistribute rip subnets route-map rip2ospf > > > network 99.99.99.1 0.0.0.0 area 51 > > > network 100.100.0.1 0.0.0.0 area 0 > > > network 100.100.1.1 0.0.0.0 area 0 > > > network 100.100.2.1 0.0.0.0 area 0 > > > network 100.100.3.1 0.0.0.0 area 0 > > > network 100.100.4.1 0.0.0.0 area 0 > > > network 100.100.5.1 0.0.0.0 area 0 > > > network 100.100.6.1 0.0.0.0 area 0 > > > network 100.100.7.1 0.0.0.0 area 0 > > > network 160.160.255.0 0.0.0.255 area 0 > > > > > > note the summary in the R1 routing table: > > > > > > Gateway of last resort is not set > > > > > > 100.0.0.0/8 is variably subnetted, 9 subnets, 2 masks > > > O 100.100.0.0/20 is a summary, 00:11:57, Null0 > > > > > > now observe router 2's table: > > > > > > 100.0.0.0/24 is subnetted, 8 subnets > > JMcL: Interesting line above. You sure that's what it said? > > > O 100.100.0.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.1.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.2.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.3.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.4.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.5.0 [110/26] via 160.160.255.1, 00:12:53, > > > TokenRing0 > > > O 100.100.6.0 [110/26] via 160.160.255.1, 00:12:54, > > > TokenRing0 > > > O 100.100.7.0 [110/26] via 160.160.255.1, 00:12:54, > > > TokenRing0 > > > 99.0.0.0/32 is subnetted, 1 subnets > > > > > > This has remained constant through several reconfigurations > and > > > several ospf > > > process resets. > > > > > JMcL: I'm not quite clear on your setup. Pick me up if I go > wrong here. > > R1 and R2 are connected by 160.160.255.0/24, yes? > > 160.160.255.0/24 is in area 0, yes? > > So R2 is also in area 0, yes? > > So why are you expecting that the backbone routes will have > been > > summarised? You haven't left the backbone yet - you haven't > crossed an > area > > boundary (referring to the quote below). > > What happens if you connect R1 and R2 by a non-backbone link? > > > > > It also remain true even if on R1 I use a more generic > network > > > 100.100.0.0 > > > 0.0.255.255 area 0 command. > > > > > > So........ > > > > > > I stand by my statement that even though you may be able to > > > enter the > > > commands, the fact is that you cannot summarize area 0 > routes > > > on a cisco > > > router, at least not that I've been able to figure out.. My > > > position is > > > further supported by the Cisco documentation, which states > "The > > > area range > > > command is used only with area border routers (ABRs). It is > > > used to > > > consolidate or summarize routes for an area. The result is > that > > > a single > > > summary route is advertised to other areas by the ABR. > Routing > > > information > > > is condensed at area boundaries." > > > > > Sorry - how does this say that you can't summarise in either > direction? I > > don't see how it backs up your position. > > > > > > http://www.cisco.com/univercd/cc/td/doc/product/software/ios121/121cgcr/ip_r > > > /iprprt2/1rdospf.htm#xtocid4 > > > watch the wrap > > > > > > Of course, I am ready to learn something new, if you've got > a > > > trick I have > > > yet to learn. > > > > > > > > > > > > > Why not summarise backbone routes for the same reasons as > > > summarising > > > > non-backbone routes - reduce routing tables, database > sizes, > > > route change > > > > propagations etc? > > > > > > In regards to the wisdom of summarizing backbone routes in > an > > > OSPF network, > > > while I was pondering your response, I went through a few > > > ideas, and I see > > > where it "might" be advantageous.. I still believe that > > > generally speaking, > > > one would want all backbone routes to be visible throughout > the > > > backbone to > > > allow for uninterrupted routing should one or more backbone > > > routers fail. > > > This assuming a redundant backbone design. > > > > > > I can't located specifics in the RFC, but I "suspect" that > Mr. > > > Moy is of > > > similar mind. > > > > > > > > JMcL: Obviously this would depend on network design - I'm > certainly not > > arguing that summarising backbone routes would be > advantageous (or even > > non-harmful) in all cases. > > > > > with all respects > > > > > > Chuck > > > -- > > And you know I respect your opinions too, Chuck. But with > all the respect > > in the world, I still reckon you're wrong on this one, > because just last > > week I had to deal with a problem caused because I'd > forgotten to put some > > area 0 range statements on an ABR. > > I have used area 0 range statements on IOS 11.2, and 12.1, at > least. And > > probably 10.3 - can't remember when we started summarising. > > > > Excerpt of config on ABR... > > area 0 range 1.4.0.0 255.255.0.0 > > area 0 range 1.5.0.0 255.255.0.0 > > area 0 range 1.6.0.0 255.255.0.0 > > area 4.1.0.0 range 4.0.0.0 255.128.0.0 > > network 1.0.0.0 0.255.255.255 area 0 > > > > excerpt of routes from ABR... > > O 1.5.0.0/16 is a summary, 00:32:13, Null0 > > C 1.4.1.0/24 is directly connected, Serial1/0.1 > > C 1.4.0.1/32 is directly connected, Loopback0 > > O 1.6.0.2/32 [110/2006] via 1.4.1.1, 00:32:13, > Serial1/0.1 > > O 1.5.1.0/24 [110/2000] via 1.4.1.1, 00:32:30, > Serial1/0.1 > > O 1.5.0.1/32 [110/2001] via 1.4.1.1, 00:32:30, > Serial1/0.1 > > O 1.4.0.0/16 is a summary, 00:32:30, Null0 > > O 1.6.1.0/24 [110/2000] via 1.4.1.1, 00:32:30, > Serial1/0.1 > > O 1.6.0.1/32 [110/2001] via 1.4.1.1, 00:32:30, > Serial1/0.1 > > O 1.5.0.2/32 [110/2006] via 1.4.1.1, 00:32:31, > Serial1/0.1 > > O 1.6.0.0/16 is a summary, 00:32:31, Null0 > > O 1.4.0.2/32 [110/6] via 1.4.100.2, 00:32:31, > Ethernet0/0/0 > > > > excerpt of routes from a (non-ABR) router in area 4.1.0.0... > > 1.0.0.0/8 is variably subnetted, 66 subnets, 4 masks > > O IA 1.5.0.0/16 [110/2520] via 4.100.1.1, 07:50:41, > Serial0.1 > > O IA 1.4.0.0/16 [110/521] via 4.100.1.1, 07:50:41, > Serial0.1 > > O IA 1.6.0.0/16 [110/2520] via 4.100.1.1, 07:50:41, > Serial0.1 > > > > No subnets of the above summaries show up on the 4.1.0.0 > router. > > > > JMcL > > > > > > > > > > > > > > > > > JMcL > > Message Posted at: http://www.groupstudy.com/form/read.php?f=7&i=56491&t=56136 -------------------------------------------------- FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
