nabz0r Veteran Posted December 23, 2014 Veteran Share Posted December 23, 2014 Guys, can someone try to explain for me these two types? Cisco docs and videos across the web couldn't help me (or I might be an idiot that don't get it sometime ) and I didn't understand the differences. Can anyone explain it to me? Thanks! Type 4 is when you advertise redistribute routes from eigrp, (or other routing protocols) and so is Type 5, it also advertise redistributed routes (or I didn't understand it right) Link to comment Share on other sites More sharing options...
sc302 Veteran Posted December 23, 2014 Veteran Share Posted December 23, 2014 maybe this will help you a bit better http://thenetworksherpa.com/ospf-why-have-a-type-4-lsa/ Link to comment Share on other sites More sharing options...
nabz0r Veteran Posted December 23, 2014 Author Veteran Share Posted December 23, 2014 maybe this will help you a bit better http://thenetworksherpa.com/ospf-why-have-a-type-4-lsa/ .. Just go that if there is no LSA 4 then LSA 5 doesn't work, but WHY? Let us consider the following: Area 0: Only Type 1 LSA Area 1: Type 1 and Type 2 LSA since there is a DR in that area Between Area 0 and Area 1 there is Type 3 LSA From R2 which is an ABR to Area 0 there is advertisement and there is Type 4 NOW: isn't Type 5 the same advertisement that is advertised in Type 4 which is the External Routes that are redistributed? WHY do we have Type 5? Edit: It should be ASBR not ABSR. LOL Link to comment Share on other sites More sharing options...
sc302 Veteran Posted December 23, 2014 Veteran Share Posted December 23, 2014 never mind...wow... Link to comment Share on other sites More sharing options...
nabz0r Veteran Posted December 23, 2014 Author Veteran Share Posted December 23, 2014 never mind...wow... w00t? Link to comment Share on other sites More sharing options...
Stokkolm Posted December 23, 2014 Share Posted December 23, 2014 The best website I've found to explain all of the LSA types is this one: http://networklessons.com/ospf/ospf-lsa-types-explained/ Type 4 Link to comment Share on other sites More sharing options...
nabz0r Veteran Posted December 24, 2014 Author Veteran Share Posted December 24, 2014 Thanks but I had already read that page. Never mind, I went through them couple of times and I guess I kind of understand the differences but not so sure though. I needed someone to explain them to me very simple and in a few words though don't know if that is even possible. OSPF is fun but I like EIGRP more especially the K Values Link to comment Share on other sites More sharing options...
Stokkolm Posted December 29, 2014 Share Posted December 29, 2014 Thanks but I had already read that page. Never mind, I went through them couple of times and I guess I kind of understand the differences but not so sure though. I needed someone to explain them to me very simple and in a few words though don't know if that is even possible. OSPF is fun but I like EIGRP more especially the K Values I think the simplest way to think of it is this: LSA Type 4 lets everyone know about the ASBR. This is needed because routers could be in differing OSPF areas and having a specific LSA for this purpose ensures everyone knows where it is. LSA Type 5 is for advertising networks that exist outside of OSPF, for instance in RIP or EIGRP. Does that help at all? EIGRP is a good and fast protocol, but if you need a link state routing protocol OSPF is the way to go. It's all about what you need I guess. Link to comment Share on other sites More sharing options...
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