The results are not in question, the timing is. My current theory is that election is always from the list of routers that a rouer has a two-way relationship with, thus the question has nothing to do with that and needs to be pushed back to: "How long does a router wait to collect two-way state neighbors before stop waiting and starting and election?"
On Wed, Nov 24, 2010 at 5:14 AM, Jason Maynard <[email protected]>wrote: > I have not read all the comments but I thought I would try this > > > > I configured OSPF on a single router and ran “debug ip ospf adja” > > > > > > *Mar 1 00:01:07.091: OSPF: Interface FastEthernet0/0 going Up > > *Mar 1 00:01:07.595: OSPF: Build router LSA for area 0, router ID 1.1.1.1, > seq 0x80000001 > > *Mar 1 00:01:47.091: OSPF: end of Wait on interface FastEthernet0/0 > > *Mar 1 00:01:47.091: OSPF: DR/BDR election on FastEthernet0/0 > > *Mar 1 00:01:47.095: OSPF: Elect BDR 1.1.1.1 > > *Mar 1 00:01:47.095: OSPF: Elect DR 1.1.1.1 > > *Mar 1 00:01:47.099: OSPF: Elect BDR 0.0.0.0 > > *Mar 1 00:01:47.099: OSPF: Elect DR 1.1.1.1 > > *Mar 1 00:01:47.103: DR: 1.1.1.1 (Id) BDR: none > > *Mar 1 00:01:47.603: OSPF: No full nbrs to build Net Lsa for interface > FastEthernet0/0 > > > > Does this help? > > > > > > > > *From:* [email protected] [mailto: > [email protected]] *On Behalf Of *David Betz > *Sent:* November-24-10 3:37 AM > > *To:* [email protected] > *Subject:* Re: [OSL | CCIE_RS] OSPF Election Time > > > > That's my current theory. However, this really shouldn't be a theory, but > scientific fact. I've looked at the RFC and still haven't found anything. > Granted, it was a skim. I'd need to scan it to be sure of > it's absence or presence. > > On Wed, Nov 24, 2010 at 2:10 AM, antonio <[email protected]> > wrote: > > Maybe you have to look at wait timer (by default equals to dead-interval) > > regards > antonio > > Il 24/11/2010 03:43, David Betz ha scritto: > > Upon closer examination of the process, it seems that DR/BDR election is > based on the candidates that are adjacencies (neighbor routers with > priority > 0). Thus, the question is pushed backed a step: when does a > router say "I've 2-way with n-number of routers on this broadcast > segment, let's begin election."? Even then, multiple routers are doing > this, but given that that is per-segment, the election results should be > the same all over. So, that part shouldn't be an issue. > > On Tue, Nov 23, 2010 at 7:58 PM, David Betz <[email protected] > > <mailto:[email protected]>> wrote: > > Yes? > > I've done this experiment myriad times and looked over the data for > a long time. What is your personal analysis of this data? Any > conclusion? I've not been any to come up with with anything based > on this data. If we are going to do our work off empirical data, we > need to have a series of tests with a specified baseline. However, > I'm more looking for an axiom from the [seemingly non-existent] > documentation. Normally I'd look at the RFC, but do not any any > reason to think that Cisco is following it at this point. > > > On Tue, Nov 23, 2010 at 7:49 PM, Jason Maynard > > <[email protected] <mailto:[email protected]>> wrote: > > Have a look at the times below. Between two routers in a > broadcast network > > *Mar 1 00:09:00.215: OSPF: end of Wait on interface FastEthernet0/0 > > *Mar 1 00:09:00.215: OSPF: DR/BDR election on FastEthernet0/0 > > *Mar 1 00:09:00.219: OSPF: Elect BDR 222.222.222.222 > > *Mar 1 00:09:00.219: OSPF: Elect DR 222.222.222.222 > > *Mar 1 00:09:00.223: OSPF: Elect BDR 0.0.0.0 > > *Mar 1 00:09:00.223: OSPF: Elect DR 222.222.222.222 > > *Mar 1 00:09:00.227: DR: 222.222.222.222 (Id) BDR: none > > *Mar 1 00:09:00.323: OSPF: 2 Way Communication to 1.1.1.1 on > FastEthernet0/0, state 2WAY > > *Mar 1 00:09:00.323: OSPF: Neighbor change Event on interface > FastEthernet0/0 > > *Mar 1 00:09:00.327: OSPF: DR/BDR election on FastEthernet0/0 > > *Mar 1 00:09:00.327: OSPF: Elect BDR 1.1.1.1 > > *Mar 1 00:09:00.331: OSPF: Elect DR 222.222.222.222 > > *Mar 1 00:09:00.331: DR: 222.222.222.222 (Id) BDR: > 1.1.1.1 (Id) > > *Mar 1 00:09:00.331: OSPF: Send DBD to 1.1.1.1 on > FastEthernet0/0 seq 0xA62 opt 0x52 flag 0x7 len 32 > > *Mar 1 00:09:00.331: OSPF: Neighbor change Event on interface > FastEthernet0/0 > > *Mar 1 00:09:00.331: OSPF: DR/BDR election on FastEthernet0/0 > > *Mar 1 00:09:00.331: OSPF: Elect BDR 1.1.1.1 > > *Mar 1 00:09:00.331: OSPF: Elect DR 222.222.222.222 > > *Mar 1 00:09:00.331: DR: 222.222.222.222 (Id) BDR: > 1.1.1.1 (Id) > > *Mar 1 00:09:00.331: OSPF: Neighbor change Event on interface > FastEthernet0/0 > > *Mar 1 00:09:00.331: OSPF: DR/BDR election on FastEthernet0/0 > > *Mar 1 00:09:00.331: OSPF: Elect BDR 1.1.1.1 > > *Mar 1 00:09:00.331: OSPF: Elect DR 222.222.222.222 > > *Mar 1 00:09:00.331: DR: 222.222.222.222 (Id) BDR: > 1.1.1.1 (Id) > > *Mar 1 00:09:00.331: OSPF: Rcv DBD from 1.1.1.1 on > FastEthernet0/0 seq 0x1376 opt 0x52 flag 0x7 len 32 mtu 1500 > state EXSTART > > *Mar 1 00:09:00.331: OSPF: First DBD and we are not SLAVE > > *Mar 1 00:09:00.379: OSPF: Rcv DBD from 1.1.1.1 on > FastEthernet0/0 seq 0xA62 opt 0x52 flag 0x2 len 52 mtu 1500 > state EXSTART > > *Mar 1 00:09:00.383: OSPF: NBR Negotiation Done. We are the MASTER > > *Mar 1 00:09:00.387: OSPF: Send DBD to 1.1.1.1 on > FastEthernet0/0 seq 0xA63 opt 0x52 flag 0x3 len 52 > > *Mar 1 00:09:00.475: OSPF: Rcv DBD from 1.1.1.1 on > FastEthernet0/0 seq 0xA63 opt 0x52 flag 0x0 len 32 mtu 1500 > state EXCHANGE > > *Mar 1 00:09:00.479: OSPF: Send DBD to 1.1.1.1 on > FastEthernet0/0 seq 0xA64 opt 0x52 flag 0x1 len 32 > > *Mar 1 00:09:00.483: OSPF: Send LS REQ to 1.1.1.1 length 12 LSA > count 1 > > *Mar 1 00:09:00.567: OSPF: Rcv LS REQ from 1.1.1.1 on > FastEthernet0/0 length 36 LSA count 1 > > *Mar 1 00:09:00.571: OSPF: Send UPD to 10.0.0.2 on > FastEthernet0/0 length 40 LSA count 1 > > *Mar 1 00:09:00.619: OSPF: Rcv DBD from 1.1.1.1 on > FastEthernet0/0 seq 0xA64 opt 0x52 flag 0x0 len 32 mtu 1500 > state EXCHANGE > > *Mar 1 00:09:00.623: OSPF: Exchange Done with 1.1.1.1 on > FastEthernet0/0 > > *Mar 1 00:09:00.623: OSPF: Rcv LS UPD from 1.1.1.1 on > FastEthernet0/0 length 64 LSA count 1 > > *Mar 1 00:09:00.627: OSPF: Synchronized with 1.1.1.1 on > FastEthernet0/0, state FULL > > *Mar 1 00:09:00.631: %OSPF-5-ADJCHG: Process 1, Nbr 1.1.1.1 on > FastEthernet0/0 from LOADING to FULL, Loading Done > > *Mar 1 00:09:00.727: OSPF: Build network LSA for > FastEthernet0/0, router ID 222.222.222.222 > > *Mar 1 00:09:00.731: OSPF: Build network LSA for > FastEthernet0/0, router ID 222.222.222.222 > > *Mar 1 00:09:00.735: OSPF: Build router LSA for area 0, router > ID 222.222.222.222, seq 0x80000004 > > *Mar 1 00:09:03.439: OSPF: Rcv LS UPD from 1.1.1.1 on > FastEthernet0/0 length 64 LSA count 1 > > *From:*Jason Maynard [mailto:[email protected] > <mailto:[email protected]>] > *Sent:* November-23-10 8:25 PM > *To:* 'David Betz'; '[email protected] > > <mailto:[email protected]>' > > > *Subject:* RE: [OSL | CCIE_RS] OSPF Election Time > > Well that depends > > How long does the device take to boot up compared to other devices > > When is the device ready to participate in the OSPF election > process (running more services on a device may take it longer to > start participating compared to a router with less services) > > DR and BDR election is done via the Hello protocol – > > OSPF Network Type | Hello | DR/BDR | > _________________________________________ > Broadcast | 10sec | Elects DR/BDR| > _________________________________________ > NonBroadcast | 30sec | Elects DR/BDR| > _________________________________________ > P2MP | 30sec | No DR/BDR | > _________________________________________ > P2MP NonBroadcast | 30sec | No DR/BDR | > _________________________________________ > P2P | 10sec | No DR/BDR | > > If you want to control which devices become the DR/BDR you can > use “*ip ospf priority” and set all devices that you do not want > to be DR/BDR to “0” *** > > Not sure exactly how may hellos before the DR/BDR election takes > place, perhaps I will lab it up to see - > > HTH > > *From:*[email protected] > <mailto:[email protected]> > [mailto:[email protected] > <mailto:[email protected]>] *On Behalf Of > *David Betz > *Sent:* November-23-10 7:32 PM > *To:* [email protected] > > <mailto:[email protected]> > > > *Subject:* [OSL | CCIE_RS] OSPF Election Time > > I've not been able to figure this out nor can I find any > documentation for this: how long does OSPF wait for others to > cast their vote before doing the DR/BDR election? > > If R1, R2, and R3 come online with 10.1.1.X/25 (X=RX) ip > addresses, and R1 and R2 see each other's messages, they will > start an election. If R3 is there, it wins... if it's too late, > R2 wins. > > When is "too late"? > > > > > _______________________________________________ > 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 > > >
_______________________________________________ For more information regarding industry leading CCIE Lab training, please visit www.ipexpert.com
