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3

There are a bunch of confusions here. Let's start with the last one. But in OSPF also get to know the routes to it's neighbors after flooding and this neighbor also share routes it's neighbors and so on. It does not(!!!!!). In link state routing neighbors do not share routes of its neighbors, their share topology of their neighbors. Link state routing ...


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If there isn’t another router on the subnet, simply remove the network statement under the OSPF configuration.


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Without configurations for some of the other routers (RO-4/RO-1) we're basically guessing. However, this sounds like a classic issue of your own routes being announced back to you. If "ISP-2" is supposed to be an ISP's router, it wouldn't be running OSPF with you. In this messy example, you've created a loop between OSPF area 0 and 1 outside of ...


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I do the same in my network, but it does work. I think the difference here is the tagging that you use to redistribute, and is not supported as you mentioned. You can do the filtering on the route map via ip prefix instead of tag. Please, check the example in my router and let me know if it helps. router ospf 1 router-id 10.254.61.254 redistribute bgp ...


3

mDNS uses a link-local multicast address (224.0.0.251) that cannot be sent off-link, so you cannot route mDNS packets. RFC 5771: 4. Local Network Control Block (224.0.0/24) Addresses in the Local Network Control Block are used for protocol control traffic that is not forwarded off link. Examples of this type of use include OSPFIGP All Routers (224.0.0.5) [...


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When two routing protocols are configured in router routing towards same destination . Router is designed to chosee routing protocol with least administrative distance (AD) value . In this scenario OSPF & EIGRP is configured . So router picks up EIGRP because it's AD value is 90 compared to OSPF AD value 110 . Upon chossing EIGRP protocal .Further to ...


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I can't answer you question particularly exactly because .i am not understanding you question but some points to clear your understanding Multiple routing protocols can run among different network s connecting each other by redistribution routes among various routing protocols.. Administrative distance value is used by layer3 devices to choose best routing ...


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The only routing protocol in common between R3 and R2 is RIPv2, so that is the only way that R2 can learn the R3 loopback because there does not seem to be any route redistribution on any of the routers. R4 can learn the R3 loopback from EIGRP, but it cannot advertise it via OSPF unless you redistribute the route from EIGRP to OSPF. Each routing protocol ...


2

You're correct. Let's illustrate it with a few facts. Section D of RFC2328 states clearly that all OSPF protocol exchanges are authenticated. The AuType field is included in all OSPF packet types (this is important): All OSPF protocol exchanges are authenticated. The OSPF packet header (see Section A.3.1) includes an authentication type field, and 64-bits ...


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Yes you are correct,as per RFC 5613, a special TLV is used for cryptographic authentication (CA-TLV) of the LLS data block. Which you can see at the bottom of your last screenshot. This TLV is to be only included in the LLS block when cryptographic authentication is enabled on the corresponding interface. The message digest of the LLS block is calculated ...


2

According to examples across the web, if two routers are directly connected with an ethernet cable, this is a point-to-point network (which totally conforms to rfc point-to-point definition). but if there is a switch between routers, that makes a broadcast network. how it is concluded from rfc definition. You can define a network by the topological ...


2

You have some problems: The two addresses, 10.1.2.6/30 and 10.1.2.2/30 are in two different networks, but they need to be in the same network for direct router connection (see this two-part answer for the specifics). Next, never use the ip default-gateway command on a router the has routing enabled (see this answer for the details). Also, the Edge router ...


2

Network topology might affect the choice of a routing protocol and make one protocol more desirable than another. The most common example is a large hub and spoke topology. In that topology, EIGRP can handle routing updates more efficiently than OSPF. The bigger difference in protocols comes down to the practical implementations of them. As others have ...


2

is there any condition where OSPF is better used than anything else (e.g EIGRP), or what kind of network is suitable using OSPF? In a heterogeneous network, all the router vendors will support the open-standard OSPF. For EIGRP, you would need a Cisco-only network, and it would close you from using routers from any other vendors. It would also create big ...


2

You can have multiple ASBRs redistributing their (set(s) of) external routes into the OSPF domain. The routes the various ASBRs generate/inject might be identical, partially overlapping or even completely disjoint, and yes, there can be multiple ASBRs generating/injecting a default route. The other routers will ingest these LSAs, but of course will apply ...


2

It turns out the Palo Alto tunnel inspection policy was the root of the issue. Once I disabled the policy in each firewall, I was able to ping through the tunnel. I used traceroute to verify from multiple networks that they were taking the GRE tunnel in R1 to reach R2 and its networks. I'll have to revisit the inspection policy at some point to get it ...


2

Why OSPF uses flooding instead of using multicast? Those are two very different concepts. OSPF on a broadcast network uses multicast to exchange routes. It floods by telling ever other OSPF router to which it is connected in the same area about all the routes it knows. We know that flooding is only possible in layer2 switch. That is a completely different ...


2

The cost on the interface may only be a small part of the total cost for using the interface. The cost to a destination is cumulative, and the local costs may only be a small part of the total cost. You simply cannot tell which interface is preferred for a given destination just by the local cost on an interface. For example, the interface with the cost of ...


1

Whenever we talk about OSPF, flooding means "send the data the any router learned form one neighbor to all other adjacent routers. " Actually flooding means a little more then that. Flooding is an algorithm to forward packet through a network which works by having each network node on the path send a packet received from one neighbor to all other ...


1

You have a couple of route-maps that are almost correct. Like you surmised, you need to use communities within BGP routing-policy. ip community-list standard permit from-ospf <asn>:1 route-map BGP_TO_OSPF deny 10 match community from-ospf route-map BGP_TO_OSPF permit 20 set tag 222 route-map OSPF_TO_BGP deny 10 match tag 222 route-map OSPF_TO_BGP ...


1

Had this conversation yesterday. Communities sound complex but are really just tags for BGP. There are a few different ways that you could potentially resolve this. Looking at the topology I am assuming that RO-1 and RO-4 are your redistribution sets. With this in mind you could set a BGP community for 65100:10 and 65200:10 (the number is arbitrary. Standard ...


1

I got it all working now, here is the config: HK_Office: interface Loopback0 ip address 10.10.0.1 255.255.255.0 ! interface Loopback1 ip address 192.168.10.1 255.255.255.0 ! interface FastEthernet1/0 ip address 172.16.0.1 255.255.255.0 duplex auto speed auto ! router ospf 10 log-adjacency-changes passive-interface default no passive-interface ...


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Add no auto-summary to your BGP configurations


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I'm adding an answer to the question as the supplier found the solution to the issue we were experiencing. I'm merely adding here his explanation, it could be useful to anyone else incurring in this event. Thank you again! [13 April 2021 12:31] I found the solution that you need to add the Virtual MAC address on one of the interfaces of both EDR. Please ...


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While IS-IS and OSPF work very similarly on the routing level (link-state, Dijkstra), likely the most important difference is that OSPF sits on top of IP (L3) while IS-IS sits on top of the data link layer (L2). Accordingly, IS-IS requires L2 connectivity between peers which isn't always available (e.g. when L3 tunneling is used with VPN or similar). ...


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A broadcast network is what you've got on an Ethernet switch (or multiple connected ones): any node can talk to any other directly. If there are VLANs, each VLAN represents its own broadcast network/domain. The distinction that RFC makes is the contrast between a broadcast network with point-to-multipoint addressing, a non-broadcast network with P2MP, and a ...


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If three routers are using OSPF and one router is using static routing To ensure communication among this networks, the solution is redistribution Redistributes the routes into static to OSPF .


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Chossing a routing protocols for a setup is depends upon design of networks , scalablity , nature of business , size of business , potential expansion in future , business requirements , cost , number of application hosted , number of sessions per seconds ,


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