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
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