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Why does EIGRP aim to be loop free?

All routing protocols try to avoid a loop topology. If there is a routing loop, data is not getting to the destination. If the path from source to destination is A -> B -> C -> D, but there is a ...
Ron Trunk's user avatar
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9 votes
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Why do summary routes get a low Administrative Distance?

Since the summarized route means that a router advertising it has knowledge of the individual routes within the summarized prefix, it is more trustworthy than the same (summarized) prefix being ...
Ron Maupin's user avatar
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When would we want to do traffic steering?

One example would be when the 'best path' is not actually desirable for the traffic in question. The selected path might be the most efficient (shortest in terms of routed hops etc.) but might ...
FrameHowitzer's user avatar
6 votes

Why do summary routes get a low Administrative Distance?

The AD of the EIGRP summary route is 5 only on the router that has the summary route configured. When the summary is advertised to other routers it has an AD of 90. The reason for the low AD is to ...
Ron Trunk's user avatar
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6 votes
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What Is The Difference Between Using Wildcard Mask In EIGRP And In OSPF?

I'll assume you are referring to the wildcard mask being used with the network ... statements in EIGRP and OSPF configurations. As in (pseudo config code) router ospf 100 router-id <...
Marc 'netztier' Luethi's user avatar
5 votes
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EIGRP metric explanation

EIGRP Metric Formula The EIGRP Metric is a combination of a measure of the entire path's cumulative delay, and the minimum bandwidth across the entire path. The delay value is value assigned to each '...
Eddie's user avatar
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5 votes
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How do OSPF and EIGRP deal with 2 exactly same routes?

Will ospf and eigrp share the 10 network on the right to their neighbors? As per my understanding link state protocols like ospf do so while eigrp being a distance vector protocol will share ...
TDurden's user avatar
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5 votes
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EIGRP failover - how do i verify it happened?

There is a command made for such checking. Use: show ip eigrp events
Viktor Borisov's user avatar
5 votes
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No passive-interface error

You have to put your interfaces into vrf 4. interface fa 2/0 ip vrf forwarding 4 An interface can only be in one vrf. Otherwise, how would the router know which interface to use? If you don't ...
Ron Trunk's user avatar
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Why does EIGRP have lower Administrative distance than OSPF?

That is because Cisco determines the AD used by its devices, and EIGRP is a Cisco protocol, so Cisco decided to make EIGRP have a lower AD than other protocols. Each vendor determines the relative ...
Ron Maupin's user avatar
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5 votes

Ramifications of turning off Spanning Tree for EIGRP network?

Spanning-tree is a loop detection / prevention mechanism. As such, it has nothing to do with EIGRP. Unless you have loops, or parallel layer-2 links in the network, STP isn't doing anything for you. ...
Ricky's user avatar
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4 votes
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How does EIGRP determine the path to far away destinations?

There seems to be a confusion here : in a distance-vector routing protocol, the routers don't just get routes to their neighbors (which would be trivial in most cases) they get their neighbor's full ...
Jeremy Gibbons's user avatar
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Choosing a routing protocol

To choose a routing protocol you should consider these topics: Configuration: How easy is to configure and troubleshoot the protocol. Efficiency: How fast it converges? How much bandwith it uses? ...
jcbermu's user avatar
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4 votes

EIGRP failover - how do i verify it happened?

Yes, you can confirm that. Once hold-time expires, the former feasible successor route immediately becomes the successor route and is installed in routing table. I do not think we have a log message ...
Hung Tran's user avatar
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4 votes

No passive-interface error

From your configs, interface FastEthernet2/0 is not part of vrf 4 that your EIGRP is configured for oneither of your routers. Try adding your interface to the vrf with the following. interface ...
A-A-Ron's user avatar
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4 votes
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Filter routes based on interface

You can specify what routes exactly you want to receive from neighbor on specific interface by using distribute-list option: (conf)# router eigrp 10 (config-router)# distribute-list 50 in Tunnel 3 ...
Andrey Prokhorov's user avatar
4 votes
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EIGRP authentication on GRE tunnel interface?

Yes, you can do that. Below is an example: Router-A# ! key chain Netlab key 13 key-string Netlabbuilder ! interface Tunnel1 description Site-B ip address 10.99.99.1 255.255.255.252 ip mtu 1400 ...
Hung Tran's user avatar
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4 votes
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EIGRP Auto-summary

Auto-summary summarizes network advertisements based on classful boundaries. Since classful addressing has been obsolete since before you were born, it's good practice to disable it.
Ron Trunk's user avatar
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4 votes
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Ramifications of turning off Spanning Tree for EIGRP network?

switch that has elected itself You should never leave the root bridge to chance. If the current root switch goes offline or is rebooted your spanning tree needs to reconverge, causing temporary ...
Zac67's user avatar
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4 votes

In router's config, why do I need to advertise the directly connected network?

I think you misunderstand the OSPF and EIGRP network statement. The network statement does not advertise a network, it tells the routing protocol which interface(s) to include in the routing protocol ...
Ron Maupin's user avatar
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4 votes
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Running multiple EIGRP processes on a router

Running multiple processes is not very common and there are not a lot of examples. One possible reason for running multiple processes is when there are two separate routing domains (e.g. when merging ...
Ron Trunk's user avatar
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4 votes
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Doesn't OSPF Have Auto Summarization?

I'm not going to get into the specifics of the various protocols other than OSPF because it is a good example to start with and it gets confusing if you pull in completely different things. Details ...
FrameHowitzer's user avatar
4 votes
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Interior vs Exterior Gateway Protocols

In practice, there is only one EGP in use today, and that is BGPv4. OSPF and EIGRP are the most common IGPs. RIP is essentially obsolete. Can a company private network be considered as an ...
Ron Trunk's user avatar
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3 votes
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Preventing Load balancing in EIGRP

If you simply want to prevent load balancing, then you can use the maximum-paths command in EIGRP to do that. Just set it to 1: router eigrp 1 maximim-paths 1 EIGRP Commands: maximum-paths (...
Ron Maupin's user avatar
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3 votes

BGP problems, cannot ping

You have not set the clock rate on the DCE side of the connection. The command is clock rate <rate>. See Cisco IOS Interface and Hardware Component Command Reference. Another problem is that ...
Ron Maupin's user avatar
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3 votes
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EIGRP neighbors discovering process

A good question, as there is a lot of inaccurate information about this. EIGRP neighbors exchange data from the EIGRP topology table. The routing table contains routes learned from different ...
Ron Trunk's user avatar
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3 votes
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BGP update source basics

To expand on @cown 's answer, the reason this works is because King initiated the connection, sending an open request to 2.2.2.2. Kong received the request on that interface, so it responded from ...
Ron Trunk's user avatar
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3 votes
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Will an EIGRP route be chosen over an OSPF route regardless of metrics?

You cannot compare metrics between different routing protocols. To solve that problem, we have Administrative Distance, which gives you a relative trustworthiness of a particular routing protocol, as ...
Ron Maupin's user avatar
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3 votes

Cannot see the differende between distance-vector and link-state

So with each of those routing protocols we have accomplished the same thing: Each router knows EVERY network or link. what did I get wrong here? You didn't get anything wrong -- you are ...
Ron Trunk's user avatar
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