Questions tagged [eigrp]
Use this tag for questions about Cisco's EIGRP - Enhanced Interior Gateway Routing Protocol.
129
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Protocols: EIGRP vs OSPF [closed]
EIGRP and OSPF are both IGP protocols, the former is a mostly Cisco protocol and the latter is a well established open standard. What are the benefits of one over the other?
Put another way, when ...
- 4,161
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Error: `EIGRP is restricted to stub configurations only on this platform`
We just bought some new Cat4507R+E distribution switches. When we bought the switches, we asked for an Advanced Services K9 image, but our reseller told us they only come with a Universal K9 image. ...
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2
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Why does the MTU need to match on interior link state routing protocols like EIGRP and OSPF?
If one tries to configure the neighbor adjacencys without matching MTU, The routers fail to become neighbors. I assume this is to protect the routing protocol from it self but I don't understand ...
- 203
9
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2
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Why do summary routes get a low Administrative Distance?
Why do summary routes get a lower AD than other routing protocols? For example: The AD of EIGRP is 90, whereas the AD of a summary route is 5.
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4
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Delay or Offset-List for EIGRP tuning?
Studying for CCNP-ROUTE - everything I read says it's preferable to use delay and offset-lists for metric tuning vs. say bandwidth in EIGRP. In practice what is more commonly used out of those two ...
- 3,310
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Can one configure several static EIGRP Neighbors on one interface?
Can one configure several static EIGRP Neighbors on one interface and are there any considerations apart from disabling split-horizon that one should consider?
- 837
9
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5
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Static redistribution into EIGRP as internal failure
I am redistributing a static route into EIGRP on a 6500. I had read here if you enter a network statement matching a static route that it would be redistributed as an internal route by EIGRP. However, ...
- 799
9
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1
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178
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EIGRP FD not the same in topology table
In EIGRP when showing topology table, i notice in some entries are like below:
P 10.1.6.0/24, 1 successors, FD is 793600
via 10.1.2.2 (2195456/281600), Serial0/0/0
via 10.1.3.2 ...
user1559625
6
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1
answer
937
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Does EIGRP use AS number/process number as it's PORT NUMBER between routers in the same AS/group?
Does EIGRP use AS number/process number as it's PORT NUMBER between routers in the same AS/group?
I know that EIGRP does NOT use TCP/UDP; I know that that EIGRP uses RTP as a mechanism to establish a ...
- 475
6
votes
2
answers
899
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Connect one router to layer 3 3750-X stack for redundancy
I'm connecting a Cisco 2851 router to a Layer 3 3750-X stack (2 switches). The Gi0/0 interface connects to an access port on the stack master.
How can I achieve redundancy from the 2851 to the ...
- 85
6
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1
answer
239
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Keep EIGRP up even through an interface flaps
Does EIGRP have a feature similar to disabling fast fallover in BGP, where we can allow a link to flap for a (hopefully definable) period of time and still leave the EIGRP neighborship up?
My ...
- 3,310
5
votes
2
answers
2k
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Summarized route not being shared in EIGRP
Working through a lab for CCNP prep. Task is simple - create 4 loopback addresses on R3 - all 172.16.X.0/24 addresses, and share the routes to neighboring routers so that they appear as /22's instead....
- 3,310
5
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2
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EIGRP topology table - unexpected behavior
Prepping for CCNP - In my topology the path R1 takes to a Loopback Ip is via R2 by default. My goal is to have a feasible successor route through R3. I've attached a diagram of topology.
https://i....
- 3,310
5
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1
answer
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Controlling route-map distribution with 'match interface' in EIGRP
I have a "Tun0" interface over which I speak EIGRP. On this same router I have a "Vlan1" interface. What i'd like to do is speak only of the interfaces that pass a route-map, e.g.
route-map foo ...
- 599
5
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3
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DMVPN EIGRP Config Error - No EIGRP Hello packets sent out interface
I've been tasked with helping to troubleshoot a DMVPN Phase 3 connection over the internet. Unfortunately, I'm not experienced with DMVPN configs and setups. We have two test devices right now that ...
- 491
5
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0
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Dual-Hub DMVPN Outage
Our backup links have always utilized a GRE tunnel based VPN to a hub. Recently we installed a second hub and migrated the primary links to GRE tunnel based VPN with EIGRP to handle routing between ...
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2
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Why does EIGRP aim to be loop free?
As far as I understand:
EIGRP is a routing protocol and handles IP packets. IP packets are outfitted with the TTL field and thus, do not loop indefinitely like layer 2 frames do.
Why does EIGRP try ...
- 264
4
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5
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Choosing a routing protocol
I have always wondered what causes an network engineer to pick EIGRP or OSPF over the other. Obviously OSPF is opened standard so can be used in a multi-vendor environment. If all equipment was cisco, ...
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4
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3
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Why I cant Ping An Address across my a routed link
I have two layer 3 switches (Main And back up) and a palo alto firewall
main switch connects to the firewall with a routed link port(gi1/1 ip add 10.1.70.2)- firewall (10.1.70.1). All connectivity is ...
- 87
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3
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Role of MTU in EIGRP metric calculation!
From what I have found on the internet, there is confusion about the role of MTU in EIGRP metric calculation.
I performed an experiment in GNS with few routers. I was not able to find any change in ...
- 253
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2
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Cisco ASA Dynamic Routing - Originating a NAT Block
Network guy working on Security problems -- hoping for some guidance!
I have a subnet that I am using as a NAT block for one of my inside subnets.
NAT from inside->outside : Convert source 10.0.0....
- 1,589
4
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1
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What is the purpose of EIGRP stubs?
I have a strong background in OSPF and am now learning EIGRP so everything I read gets compared to my existing knowledge of OSPF. Because of this, I don't see the purpose of EIGRP stubs.
In OSPF, you ...
- 1,005
4
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1
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EIGRP to iBGP metric calculation
Consider the following output:
router#show ip bgp vpnv4 rd 300:1 5.5.5.5/26
BGP routing table entry for 300:1:5.5.5.5/26, version 538213
Paths: (2 available, best #2, no table)
Advertised to ...
- 2,535
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1
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RIP V2 multicasting looks as broadcasting at IP add 224.0.0.9
In RIPv1 the packets are broadcasted out all ports with dest. IP 255.255.255.255. In v2 they are multicasted with dest. IP 224.0.0.9. In Packet Tracer, this v2 packet is transmitted over all ...
- 253
4
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1
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76
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Filter routes based on interface
In EIGRP is there a way to filter routes entering from a specific interface?
The intent is to protect the network core's routing table from receiving misconfigured or maliciously-inserted routes from ...
- 666
4
votes
1
answer
733
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EIGRP MD5 authentication
I would like to know more about EIGRP MD5 authentication in the following situation:
an attacker captured the MD5 hashed key and send to the target router to fake the authentication, is it possible?
...
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4
votes
3
answers
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Why does EIGRP have lower Administrative distance than OSPF?
I have given the following network diagram and been told that,
Since EIGRP has a better (lower) administrative distance than OSPF, the router on the far left will use the EIGRP path and publish ...
- 613
4
votes
1
answer
4k
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eigrp configuration problem over frame-relay
I have a set up with back to back connection with EIGRP over frame-relay, mention below the device connection setup using GNS3.
Problem is: I am configuring EIGRP over frame-relay, but its not ...
- 41
4
votes
1
answer
2k
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eigrp load balacing - per packet or per destination
Assume i have no cef enabled and there are 2 paths with the same cost ( both traffic share count = 1)
Router#show ip route 20.20.20.1
Routing entry for 20.20.20.0/24
Known via "eigrp 10", distance ...
- 529
3
votes
2
answers
1k
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No passive-interface error
I'm trying to nest some EIGRP configurations on a router in GNS3.
I'm trying to connect the EIGRP 2801 in SW01 to RTR-01 and EIGRP 2864 to RTR-02 when I do.
When I put no passive-interface ...
- 133
3
votes
2
answers
686
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EIGRP failover - how do i verify it happened?
I have 2 links to a destination and EIGRP was setup. The faster link is the successor and the slower link is the feasible successor.
Switch1#show ip eigrp topology 192.168.1.0
EIGRP-IPv4 Topology ...
- 529
3
votes
2
answers
525
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Cannot see the differende between distance-vector and link-state
At link-state routing protocols each router advertises every link he knows about to the next router, which again advertises his links and so on until every router knows all links in his area. So every ...
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2
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In router's config, why do I need to advertise the directly connected network?
I have learned that, in routing config, a router must advertise all of its networks.
For example, in this topo:
Router A need to network 192.168.1.1 0.0.0.255 and network 100.1.1.2 0.0.0.255
But why ...
- 131
3
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1
answer
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Why can't I ping in this situation?
This is the topology
As you can see routers and switches are all named out, so I will use those names to explain the issue.
First of all this network consists of VLANs, WANs running on EIGRP and ...
- 155
3
votes
2
answers
112
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EIGRP neighbors discovering process
Quick question regarding EIGRP, as far I know, EIGRP has two tables: neighbors, and topology, and the router has its routing table obtained with DUAL algorithm applied to the topology table.
...
- 1,085
3
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1
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EIGRP Auto-summary
One more question about EIGRP,
EIGRP auto-summary what is the impact on the network ? i was reading about but it was not clear for me.
And why is it a good Cisco practice to be disabled ?
I am ...
- 328
3
votes
1
answer
847
views
"Debug ip eigrp" command, output interpretation?
"Debug ip eigrp" command, output interpretation?
as you see in this output, it's a line from "Show ip eigrp" command, output
IP-EIGRP(Default-IP-Routing-Table:90): Int 172.30.7.0/24 M 2297856 - ...
- 475
3
votes
2
answers
590
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EIGRP unequal load balancing, variance command
Is correct to say that the value inserted in the variance command, lets say the value of "2" on a route that has a cost of, lets say "100", will unequally load balance all routes up to a cost of 200 ?
...
- 328
3
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1
answer
76
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EIGRP Adjacency Table
From Cisco IP Routing by Alex Zinin
According to this figure Adjacency Table gets messages from DUAL module also.As far as I know, Adjacency Table is populated only because of Hello packets exchanged ...
- 536
2
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2
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How to stop a connected network from being advertised in eigrp?
How to stop a connected network (gig2/1) from being advertised in eigrp? I was thinking to use passive interface but the connected subnet would still be advertised because of "network 10.0.0.0" under ...
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2
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1
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645
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When would we want to do traffic steering?
After going over EIGRP, I ran into offset lists which allow the modification of the metric of routes advertised by EIGRP and provide the option of traffic engineering.
I am not very experienced with ...
- 759
2
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3
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5k
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EIGRP metric explanation
I'm looking for an understanding of how the metrics are structured within EIGRP, this includes the routing table, and also the topology table. I'm sure I'm not the only one that finds the concepts of ...
- 375
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3
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How do OSPF and EIGRP deal with 2 exactly same routes?
If you refer this diagram,
Will ospf and eigrp share the 10 network on the right to their neighbors?
I am asking the question in two separate scenarios using a single protocol at a time and not ...
- 394
2
votes
2
answers
1k
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Preventing Load balancing in EIGRP
In a recent project, I have been told to consider four Hubs (two in HQ, and two in DR), where each branch will have EIGRP neighborships with all four, as part of a DMVPN based WAN. I have tested this ...
- 400
2
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2
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364
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How does EIGRP determine the path to far away destinations?
10.0.10.0/24 10.0.11.0/24 192.168.178.0/24
R1 ╚════════════╝ R2 ╚════════════╝ R3 ╚════ R3 LAN ════╝
In OSPF each router knows the full topology, so it uses the Dijkstra algorithm to ...
- 463
2
votes
1
answer
3k
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How exactly does "bandwidth" in the Cisco IOS affect network performance?
While troubleshooting a problem that a client reported I came across the IOS interface setting bandwidth. For whatever reason their interface was set to bandwidth 20. I understand that it doesn't ...
- 348
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2
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336
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EIGRP advertising of routes for other networks behind us
Continuing my expedition in to trying to learn EIGRP and other routing techniques in GNS3, I now have another theoretical network, depicted below:
Everything in the red area is a mystery. We do not ...
- 145
2
votes
2
answers
437
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How to ping from PC on EIGRP area to PC on OSPF area without middle router?
This is my topology.
And I can send a package to every router and PC within the colored area, how can I ping from a PC on EIGRP area to a PC on the OSPF area? I heard about default route but I saw it ...
- 23
2
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1
answer
540
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EIGRP authentication on GRE tunnel interface?
I want to implement authentication on EIGRP updates.
Can I enable EIGRP authentication on a GRE tunnel interface instead of physical interface?
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1
answer
292
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How can I clear all EIGRP routes?
Working through NetSim, I graded my work and found that at first I put the wrong IP address in the EIGRP routing table, so I then tried adding the write one.
I then tried to grade my work again, and ...
