# How could the LAN still availabe if there is NOT DR/BDR routers **URL:** \ **Category:** CCNP Enterprise\ **Tags:** networking\ **Created:** [August 8, 2022, 2:47am UTC](https://legacy-community.ine.com/t/how-could-the-lan-still-availabe-if-there-is-not-dr-bdr-routers/2719 "2022-08-08T02:47:38Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![major133-ac9365513dd](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@major133-ac9365513dd](https://legacy-community.ine.com/u/major133-ac9365513dd)\ **Post date:** [August 8, 2022, 2:47am UTC](https://legacy-community.ine.com/t/how-could-the-lan-still-availabe-if-there-is-not-dr-bdr-routers/2719/1 "2022-08-08T02:47:39Z")
Hi Everyone ![image_2022-08-08_043119942](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/3799075456f1187538d904c086811381bdb65b91.png) ![image_2022-08-08_043355178](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/f200420c88c2422ff187058bb53448bf4f698c55.png) all routers are within area 1 R1 is DR with pri=100 R2 is BDR with pri=50 i will try to disable R2 (BDR) and see what will happened BUT 1. before R2 fail, this is what R3 see.R3 sees that there is a BDR which is 10.1.12.2 ![image_2022-08-08_043528320](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/64f3fb91ff1255fd145043003b65c7302beb0c6e.png) R2(config)#interface fastEthernet 0/0 R2(config-if)#shutdown after the BDR fail , R1(DR) send LSupdate message to dst=224.0.0.5 all ospf routers and received LSack from all DROthers ![image_2022-08-08_043721055](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/57fb8e553062ffb31b0e757a49597dd564486a62.png) and this is the output from R3 after the BDR fail the BDR field is 0.0.0.0 ![image_2022-08-08_043818445](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/6482a1066c9e92aaf6813ee437de4acb0cadbfb6.png) the first question is := the question is,how could this happened ? i thought that we should have BOTH DR AND BDR at the same time =================================================== please keep follow me .this LAN has DR only which is R1 but the BDR is down there is not any BDR but i`ll disable the DR R1 R1(config)#interface fastEthernet 0/0 R1(config-if)#shutdown ![image_2022-08-08_044102042](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/f489242d8cf155364214431f5897b53d487359a5.png) but i don`t see any difference in the wireshark # the second question, why i don`t see anything happened when the DR failed like what happend when the BDR failed ? # the third question, how could we have a LAN in OSPF which does not have DR NOR BDR routers ? R3,R4 and R5 now are DROther ![image_2022-08-08_044355049](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/7ca022ec8d81f80a74e6e954a50a1bd52a5cb989.png) let`s add link on R3 to see what will happened R3(config-if)#int loo0 R3(config-if)#ip address 3.3.3.3 255.255.0.0 R3(config-if)#ip ospf 1 area 1 R3(config-if)#ip ospf network point-to-point ![image_2022-08-08_044633274](https://us1.discourse-cdn.com/flex015/uploads/ine/original/1X/afbee0cf3d54dc0d5b7aa9376d22d49147fd8561.png) i don`t see anything happend .R3 don`t send any updates the forth question,why R3 didn`t send any updates ? ![image_2022-08-08_044830722|666x500](upload://zK6cJSLUIULSWA4jCU3DxsC5skB.png) R4 didn`t get any OSPF updates from R3, why ? =============================== fifth question, if the DR is up and the BDR failed, how the DROthers detect that the BDR failed and need to elect another BDR ? what is the difference between DR failed and BDR failed from DROthers point of view ? ---
**Author:** ![kbogart-81b6c89deee9](https://avatars.discourse-cdn.com/v4/letter/k/4af34b/32.png) [@kbogart-81b6c89deee9](https://legacy-community.ine.com/u/kbogart-81b6c89deee9)\ **Post date:** [August 8, 2022, 11:26pm UTC](https://legacy-community.ine.com/t/how-could-the-lan-still-availabe-if-there-is-not-dr-bdr-routers/2719/2 "2022-08-08T23:26:56Z")
Hello Major133, I see that you have asked a lot of questions in this Community about OSPF over the last several weeks. Your curiosity is good and the fact that you even create labs and watch sniffer traces is great. Many people are too lazy to do that. However, before I ( or anyone else on this forum) attempts to answer your question, I have to ask…before posing your question here, what research about OSPF functionality have you done on your own? If your answer is, “_I’ve spent significant time reading through RFC2328, and I can’t find my answer_” then that’s one thing. But nothing you’ve written in this question (or in previous questions) indicates that you’ve ever gone to the RFC and tried to find your answers there. I do not write this to shame you or embarrass you. However, part of the learning process should be to start with the RFCs, the IEEE documents, and whatever standard you need to read through before posting your question on a public forum such as this one. Remember that any answer we give you could be disputed, but an answer your find for yourself in an RFC or IEEE document is hard to refute. So I ask you, have you searched through RFC 2328 to find your answer to this question? [https://www.rfc-editor.org/rfc/rfc2328.html](https://www.rfc-editor.org/rfc/rfc2328.html) ---
**Author:** ![major133-ac9365513dd](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@major133-ac9365513dd](https://legacy-community.ine.com/u/major133-ac9365513dd)\ **Post date:** [August 9, 2022, 12:39am UTC](https://legacy-community.ine.com/t/how-could-the-lan-still-availabe-if-there-is-not-dr-bdr-routers/2719/3 "2022-08-09T00:39:20Z")
> [@kbogart-81b6c89deee9](#): > > but an answer your find for yourself in an RFC or IEEE document is hard to refute. but i don`t understand RFCs.is there another resource other that RFCs ? I Hate RFCs ---
**Author:** ![major133-ac9365513dd](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@major133-ac9365513dd](https://legacy-community.ine.com/u/major133-ac9365513dd)\ **Post date:** [August 9, 2022, 12:52am UTC](https://legacy-community.ine.com/t/how-could-the-lan-still-availabe-if-there-is-not-dr-bdr-routers/2719/4 "2022-08-09T00:52:08Z")
Ok sir,if you find any external Link i could read and i will get the answer (of course other than RFCs) that will be fine for me i don`t want to waste your time with me. i know you`re so busy and you have your own personal life and you don`t have much time for this.