Unless you misinterpret what IOS is telling you, that is :-)
-- Marko Milivojevic - CCIE #18427 Senior Technical Instructor - IPexpert FREE CCIE training: http://bit.ly/vLecture Mailto: markom_at_ipexpert.com Telephone: +1.810.326.1444 Web: http://www.ipexpert.com/ On Tue, Oct 19, 2010 at 18:57, Larry Hadrava <larryh12203_at_gmail.com> wrote: > Thanks Bob - you just can't argue with proof by IOS / debug!!! > > Thanks > Larry Hadrava > CCIE #12203 > Check Out MyBlog: http://ccie12203.wordpress.com/ > > > > > > On Tue, Oct 19, 2010 at 2:42 PM, Bob Sinclair <bob_at_bobsinclair.net> wrote: > >> Hi Mike, >> >> I think you will find that the maximum OSPF metric is actually 2^24. B This >> is the size of the metric field in the LSA. >> >> R5(config-router)#default-metric ? >> B <1-16777214> B OSPF default metric >> >> Above shows maximum metric that can still be advertised. B BTW; B a metric of >> 0 will also be advertised. >> >> Turn on debug ip ospf lsa-generation, kill an external route, and you will >> see the LSA is withdrawn by advertising the poisoned metric, 16777215 >> >> R1#debug ip osp lsa-generation >> OSPF summary lsa generation debugging is on >> R1# >> *Oct 19 18:47:02.867: BGP(0): route 158.10.107.0/24 modified >> *Oct 19 18:47:02.991: OSPF: Generate external LSA 158.10.107.0, mask >> 255.255.255.0, type 5, age 3600, metric 16777215, tag 0, metric-type 2, seq >> 0x80000005 >> >> HTH, >> >> Bob Sinclair CCIE 10427 CCSI 30427 >> CIERS2 Online Instructor >> www.tinyurl.com/ciers2online >> >> >> >> > -----Original Message----- >> > From: nobody_at_groupstudy.com [mailto:nobody_at_groupstudy.com] On Behalf Of >> > Mike Kiefer >> > Sent: Tuesday, October 19, 2010 1:47 PM >> > To: ccielab_at_groupstudy.com >> > Subject: OSPF Metric of > 65535??? WTF! >> > >> > I was always under the impression the maximum metric of OSPF is 65535. >> > Anything beyond that wouldn't make it into the routing table. The >> > behavior >> > would be similar to a RIP route with a hop count of 16 that's >> > considered >> > unreachable. >> > >> > I noticed a few routes on our production network that exceeded 65535 >> > mainly >> > because of network engineer stupidity. >> > >> > So I made a real simple lab in GNS3. R1 connects to R2 connects to R3. >> > R1, R2, >> > and R3 have 1.1.1.1, 2.2.2.2, and B 3.3.3.3 as loopbacks and all of the >> > links >> > are maxed out with ip ospf cost 65535. >> > >> > >> > R1(config-if)#do sh ip route >> > Codes: C - connected, S - static, R - RIP, M - mobile, B - BGP >> > B B B B D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area >> > B B B B N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2 >> > B B B B E1 - OSPF external type 1, E2 - OSPF external type 2 >> > B B B B i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS >> > level-2 >> > B B B B ia - IS-IS inter area, * - candidate default, U - per-user >> > static >> > route >> > B B B B o - ODR, P - periodic downloaded static route >> > >> > Gateway of last resort is not set >> > >> > B B B 1.0.0.0/32 is subnetted, 1 subnets >> > C B B B 1.1.1.1 is directly connected, Loopback0 >> > B B B 2.0.0.0/32 is subnetted, 1 subnets >> > O IA B B 2.2.2.2 [110/131070] via 12.1.1.2, 00:07:10, FastEthernet0/0 >> > B B B 3.0.0.0/32 is subnetted, 1 subnets >> > O IA B B 3.3.3.3 [110/196605] via 12.1.1.2, 00:02:11, FastEthernet0/0 >> > B B B 12.0.0.0/24 is subnetted, 1 subnets >> > C B B B 12.1.1.0 is directly connected, FastEthernet0/0 >> > B B B 13.0.0.0/24 is subnetted, 1 subnets >> > O B B B 13.1.1.0 [110/131070] via 12.1.1.2, 00:02:21, FastEthernet0/0 >> > >> > >> > R1(config-if)#do sh ip ospf data summ >> > >> > B B B B B B OSPF Router with ID (1.1.1.1) (Process ID 1) >> > >> > B B B B B B B B Summary Net Link States (Area 0) >> > >> > B Routing Bit Set on this LSA >> > B LS age: 654 >> > B Options: (No TOS-capability, DC, Upward) >> > B LS Type: Summary Links(Network) >> > B Link State ID: 2.2.2.2 (summary Network Number) >> > B Advertising Router: 2.2.2.2 >> > B LS Seq Number: 80000002 >> > B Checksum: 0xEE3D >> > B Length: 28 >> > B Network Mask: /32 >> > B B B B TOS: 0 B Metric: 65535 >> > >> > B Routing Bit Set on this LSA >> > B LS age: 471 >> > B Options: (No TOS-capability, DC, Upward) >> > B LS Type: Summary Links(Network) >> > B Link State ID: 3.3.3.3 (summary Network Number) >> > B Advertising Router: 3.3.3.3 >> > B LS Seq Number: 80000001 >> > B Checksum: 0xA480 >> > B Length: 28 >> > B Network Mask: /32 >> > B B B B TOS: 0 B Metric: 65535 >> > >> > How do I get a routing metric > 65535? Why are both 2.2.2.2 and 3.3.3.3 >> > only >> > showing 65535 in the DB and higher metrics in the routing table? Isn't >> > the >> > 65535 based on the fact that there are only 16 bits for metric? >> > >> > What gives??? >> > >> > >> > Blogs and organic groups at http://www.ccie.net >> > >> > _______________________________________________________________________ >> > Subscription information may be found at: >> > http://www.groupstudy.com/list/CCIELab.html >> > >> > >> > >> > >> > >> > >> > >> > No virus found in this incoming message. >> > Checked by AVG - www.avg.com >> > Version: 9.0.862 / Virus Database: 271.1.1/3206 - Release Date: >> > 10/19/10 02:34:00 >> >> >> Blogs and organic groups at http://www.ccie.net >> >> _______________________________________________________________________ >> Subscription information may be found at: >> http://www.groupstudy.com/list/CCIELab.html > > > Blogs and organic groups at http://www.ccie.net > > _______________________________________________________________________ > Subscription information may be found at: > http://www.groupstudy.com/list/CCIELab.html Blogs and organic groups at http://www.ccie.netReceived on Tue Oct 19 2010 - 19:28:27 ART
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