Antonio has a good example to play with: http://www.ccie18473.net/dynamips/dynamips.htm#isis-att-bit
2009/12/21 André Luiz Bernardes <[email protected]> > Adam, you mentioned that we can overcome the default att bit behavior with > set-attached-bit feature. I suppose this could be used where default route > between L1 and L1/L2 routers is wanted but they are on same areas. > > Any practical examples on that? I’m gonna google it… > Andre > > > > On Mon, Dec 21, 2009 at 5:10 PM, Bryan Bartik <[email protected]>wrote: > >> Right, the key thing to remember is that it's not the level type (1 or 2) >> that determines whether the ATT bit set, but whether there is a peer in a >> different from an L1 peer on the router. That peer can be L1 (multi-area) or >> L2. Example: >> >> R1-----area 49.0012-----R2-----area 49.0025-----R5 >> >> R2 has two L1 neighbors (under two processes of course). >> R2 would set the ATT bit in both L1 LSP, one for each process. >> R1 and R5 would both have default routes towards R2. >> >> >> On Mon, Dec 21, 2009 at 10:31 AM, Vitkovsky, Adam < >> [email protected]> wrote: >> >>> Yes please if there are multiple is-is processes configured -the router >>> starts to advertise the att-bit in the l1 lsp >>> >>> But I believe this would only be true if the processes would have been >>> configured with different area numbers >>> >>> >>> >>> Also I’d like to ask regarding the default route >>> >>> I’m not sure if I remember that correctly but I guess I didn’t see the >>> default route in the link state database on the l1/2 router –and saw it only >>> on the l1 router >>> >>> Almost like the l1 router creates the default route on its own based on >>> the att bit received >>> >>> >>> >>> Adam Vitkovsky >>> ------------------------------ >>> >>> *From:* Rick Mur [mailto:[email protected]] >>> *Sent:* Monday, December 21, 2009 5:15 PM >>> *To:* Bryan Bartik >>> *Cc:* Vitkovsky, Adam; [email protected] >>> >>> *Subject:* Re: [OSL | CCIE_SP] CCIE_SP Digest, Vol 33, Issue 23 >>> >>> >>> >>> Does this mean that the router is aware of multiple IS-IS processes and >>> therefore advertises the default with ATT-bit? (only way to have multiple >>> level 1 areas on 1 router) >>> >>> >>> >>> Learning something new every day :-) Thanks for correcting me Bryan. >>> >>> >>> >>> >>> >>> -- >>> Regards, >>> >>> Rick Mur >>> CCIE2 #21946 (R&S / Service Provider) >>> Sr. Support Engineer – IPexpert, Inc. >>> URL: http://www.IPexpert.com >>> >>> >>> >>> On 21 dec 2009, at 17:02, Bryan Bartik wrote: >>> >>> >>> >>> Adam, >>> >>> That is right. In fact, if you have a router connected to multiple areas >>> via level 1, ATT bit is set as well by the router that is connected to >>> multiple areas. >>> >>> On Mon, Dec 21, 2009 at 8:20 AM, Vitkovsky, Adam < >>> [email protected]> wrote: >>> >>> Yes please I meant l2 routers in this case :) >>> Though with the multi area feature the l1/2 router can connect to l1 >>> routers in different areas >>> I believe the att bit is set automatically in l1 lsp only when the L1/2 >>> router interconnects different areas (via connections to l1 or l2 routers) >>> >>> >>> Adam Vitkovsky >>> >>> >>> -----Original Message----- >>> From: Rick Mur [mailto:[email protected]] >>> >>> Sent: Monday, December 21, 2009 3:34 PM >>> To: Vitkovsky, Adam >>> Cc: [email protected] >>> >>> Subject: Re: [OSL | CCIE_SP] CCIE_SP Digest, Vol 33, Issue 23 >>> >>> But an L1L2 router cannot connect to an L1 router in another area, since >>> it shares the same L1 domain :-) >>> You might be right though when the L2 part of the L1L2 router is >>> connected to an L2 router in another area, but I can't recall that from >>> things I tested. >>> >>> -- >>> Regards, >>> >>> Rick Mur >>> CCIE2 #21946 (R&S / Service Provider) >>> Sr. Support Engineer - IPexpert, Inc. >>> URL: http://www.IPexpert.com >>> >>> On 21 dec 2009, at 13:09, Vitkovsky, Adam wrote: >>> >>> > I believe l1/l2 router will advertise a default route only when it >>> connects two different areas as defined by the net id (ie 49.xxxx.)by >>> default >>> > -are the r1 and r5 routers connected to different area than the r2 is a >>> part of? >>> > You should be able to overcome this behavior by using the att bit >>> control feature >>> > -where you can set the att bit based on the match in the route-map >>> > In that route-map you'll match for the net id (clns address) of the >>> upstream router/s >>> > >>> > >>> > Adam Vitkovsky >>> > >>> > -----Original Message----- >>> > From: [email protected] [mailto: >>> [email protected]] On Behalf Of >>> [email protected] >>> > Sent: Sunday, December 20, 2009 4:46 PM >>> > To: [email protected] >>> > Subject: CCIE_SP Digest, Vol 33, Issue 23 >>> > >>> > Send CCIE_SP mailing list submissions to >>> > [email protected] >>> > >>> > To subscribe or unsubscribe via the World Wide Web, visit >>> > http://onlinestudylist.com/mailman/listinfo/ccie_sp >>> > or, via email, send a message with subject or body 'help' to >>> > [email protected] >>> > >>> > You can reach the person managing the list at >>> > [email protected] >>> > >>> > When replying, please edit your Subject line so it is more specific >>> > than "Re: Contents of CCIE_SP digest..." >>> > >>> > >>> > Today's Topics: >>> > >>> > 1. Re: Volume 2 section 1 Multiprotocol Challange lab ISIS task >>> > 2.2 (Thomas J. Loran) >>> > >>> > >>> > ---------------------------------------------------------------------- >>> > >>> > Message: 1 >>> > Date: Sun, 20 Dec 2009 15:45:48 +0000 >>> > From: "Thomas J. Loran" <[email protected]> >>> > Subject: Re: [OSL | CCIE_SP] Volume 2 section 1 Multiprotocol >>> > Challange lab ISIS task 2.2 >>> > To: Rick Mur <[email protected]> >>> > Cc: Marko, "[email protected]" <[email protected]> >>> > Message-ID: <[email protected]> >>> > Content-Type: text/plain; charset="us-ascii" >>> > >>> > Yes with the is-type level-1 command >>> > >>> > See the whole isis database and notice no L2 database. I did a R1, R2, >>> R5 reload and it did not fix the issue >>> > >>> > R2#sh isis database detail >>> > >>> > IS-IS Level-1 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 0x00000015 0x737B 918 >>> 0/0/0 >>> > Auth: Length: 9 >>> > Area Address: 49.1155 >>> > NLPID: 0x81 0xCC >>> > Hostname: R1 >>> > IP Address: 125.125.125.1 >>> > Metric: 2 IP 172.16.21.0/24 >>> > Metric: 2 IP 125.125.125.1/32 >>> > Metric: 2 IS-Extended R2.00 >>> > Metric: 0 ES R1 >>> > R2.00-00 * 0x0000000F 0x457A 1022 >>> 0/0/0 >>> > Auth: Length: 9 >>> > Area Address: 49.1155 >>> > NLPID: 0xCC >>> > Hostname: R2 >>> > IP Address: 125.125.125.2 >>> > Metric: 10 IP 172.16.52.0/24 >>> > Metric: 10 IP 172.16.21.0/24 >>> > Metric: 0 IP 125.125.125.2/32 >>> > Metric: 10 IS-Extended R1.00 >>> > Metric: 10 IS-Extended R5.03 >>> > R5.00-00 0x00000015 0xBBF9 1019 >>> 0/0/0 >>> > Auth: Length: 9 >>> > Area Address: 49.1155 >>> > NLPID: 0x81 0xCC >>> > Hostname: R5 >>> > IP Address: 125.125.125.5 >>> > Metric: 2 IP 172.16.52.0/24 >>> > Metric: 2 IP 125.125.125.5/32 >>> > Metric: 2 IS-Extended R5.03 >>> > Metric: 0 ES R5 >>> > R5.03-00 0x00000001 0x3976 1019 >>> 0/0/0 >>> > Auth: Length: 9 >>> > Metric: 0 IS-Extended R5.00 >>> > Metric: 0 IS-Extended R2.00 >>> > >>> > From: Rick Mur [mailto:[email protected]] >>> > Sent: Sunday, December 20, 2009 8:42 AM >>> > To: Thomas J. Loran >>> > Cc: [email protected]; Marko Milivojevic >>> > Subject: Re: Volume 2 section 1 Multiprotocol Challange lab ISIS task >>> 2.2 >>> > >>> > Is R2 a full L1 router? L1/L2 routers do not receive the default, only >>> pure L1 ones. >>> > >>> > Otherwise try it with a different version, I know the proctorlabs 7200s >>> have a bit old release and there are some strange bugs in it. Maybe this is >>> one of them. For the workbook lab it doesn't matter, technological you are >>> correct :-) >>> > >>> > Try it with Dynamips on the latest 12.2S release. >>> > >>> > -- >>> > Regards, >>> > >>> > Rick Mur >>> > CCIE2 #21946 (R&S / Service Provider) >>> > Sr. Support Engineer - IPexpert, Inc. >>> > URL: http://www.IPexpert.com >>> > >>> > On 20 dec 2009, at 16:23, Thomas J. Loran wrote: >>> > >>> > >>> > I should have mentioned that this was before route-leaking >>> > >>> > >>> > From: Rick Mur [mailto:[email protected]] >>> > Sent: Sunday, December 20, 2009 8:20 AM >>> > To: Thomas J. Loran >>> > Cc: [email protected]<mailto:[email protected]>; >>> Marko Milivojevic >>> > Subject: Re: Volume 2 section 1 Multiprotocol Challange lab ISIS task >>> 2.2 >>> > >>> > Once you enable route leaking, in some cases the default will not be >>> advertised anymore. I believe this has to do with the S train specifically. >>> Try and remove the route-leaking and see if you then receive a default on >>> R2. >>> > >>> > >>> > -- >>> > Regards, >>> > >>> > Rick Mur >>> > CCIE2 #21946 (R&S / Service Provider) >>> > Sr. Support Engineer - IPexpert, Inc. >>> > URL: http://www.IPexpert.com >>> > >>> > On 19 dec 2009, at 22:43, Thomas J. Loran wrote: >>> > >>> > >>> > >>> > In the Vol II section 1 multiprotocol Challenge A task 2.2 we have >>> to leak additional routes into R2 so everything stays connected if one of >>> the link goes down. I understand that. I know that I need /32 for routes >>> later on. >>> > >>> > What I do not understand is why R1 and R5, the L1/L2 routers do not >>> leak a default route into R2. I thought the L1/L2 routers were supposed >>> to set the ATT bit so R2 has a way out of the network >>> > >>> > R2# >>> > IS-IS Level-1 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 0x00000031 0x6E4B 1058 >>> 0/0/0 >>> > R2.00-00 * 0x00000032 0x4661 977 >>> 0/0/0 >>> > R5.00-00 0x00000035 0xAECD 980 >>> 0/0/0 >>> > R5.03-00 0x00000008 0x2B7D 960 >>> 0/0/0 >>> > >>> > >>> > R1#sh isi database >>> > >>> > IS-IS Level-1 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 * 0x00000031 0x6E4B 891 >>> 0/0/0 >>> > R2.00-00 0x00000032 0x4661 806 >>> 0/0/0 >>> > R5.00-00 0x00000035 0xAECD 809 >>> 0/0/0 >>> > R5.03-00 0x00000008 0x2B7D 790 >>> 0/0/0 >>> > IS-IS Level-2 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 * 0x0000000B 0x0EBF 886 >>> 0/0/0 >>> > R5.00-00 0x0000000B 0x1228 518 >>> 0/0/0 >>> > R1# >>> > >>> > R5#sh is database >>> > >>> > IS-IS Level-1 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 0x00000031 0x6E4B 844 >>> 0/0/0 >>> > R2.00-00 0x00000032 0x4661 763 >>> 0/0/0 >>> > R5.00-00 * 0x00000035 0xAECD 769 >>> 0/0/0 >>> > R5.03-00 * 0x00000008 0x2B7D 750 >>> 0/0/0 >>> > IS-IS Level-2 Link State Database: >>> > LSPID LSP Seq Num LSP Checksum LSP Holdtime >>> ATT/P/OL >>> > R1.00-00 0x0000000B 0x0EBF 840 >>> 0/0/0 >>> > R5.00-00 * 0x0000000B 0x1228 476 >>> 0/0/0 >>> > >>> > >>> > >>> > I do not see any ATT bit being set and L2 is definitely an L1 only >>> router and R! and R5 are definitely L1/L2 routers. In Doyles' Volume 1 >>> Routing book page 580 he discusses this and suggests turning on CLNS routing >>> on both the interface and the routers (default) I did that and am still not >>> getting the ATT bit set. >>> > >>> > What am I doing wrong? AM I wrong to look for the ATT bit / default >>> route in this scenario? >>> > >>> > All three routers are 7200 running version 12.2(18)S2 >>> > >>> > thanks >>> > >>> > Thomas Loran >>> > CCIE #7113 >>> > >>> > >>> > >>> > -------------- next part -------------- >>> > An HTML attachment was scrubbed... >>> > URL: >>> http://onlinestudylist.com/pipermail/ccie_sp/attachments/20091220/46d8af68/attachment.htm >>> > >>> > End of CCIE_SP Digest, Vol 33, Issue 23 >>> > *************************************** >>> > _______________________________________________ >>> > For more information regarding industry leading CCIE Lab training, >>> please visit www.ipexpert.com >>> >>> _______________________________________________ >>> For more information regarding industry leading CCIE Lab training, please >>> visit www.ipexpert.com >>> >>> >>> >>> >>> -- >>> Bryan Bartik >>> CCIE #23707 (R&S, SP), CCNP >>> Sr. Support Engineer - IPexpert, Inc. >>> URL: http://www.IPexpert.com >>> >>> >>> >> >> >> >> -- >> Bryan Bartik >> CCIE #23707 (R&S, SP), CCNP >> Sr. Support Engineer - IPexpert, Inc. >> URL: http://www.IPexpert.com >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> > -- Bryan Bartik CCIE #23707 (R&S, SP), CCNP Sr. Support Engineer - IPexpert, Inc. URL: http://www.IPexpert.com
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