EIGRP Flapping (retry limit exceeded) ???

[asaykao73]

Hi All,

This morning we're seeing EIGRP flap between 10.108.255.1 and 10.108.255.2 and nothing has changed on the network.

Topology:

[10.108.255.1(ASR)] --> [Nexus 5K] --> [3750] --> [10.108.255.2]

Logs on 10.108.255.1:

Mar  9 11:26:23.435 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is down: retry limit exceeded

Mar  9 11:26:24.107 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is up: new adjacency

Mar  9 11:27:43.610 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is down: retry limit exceeded

Mar  9 11:27:43.730 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is up: new adjacency

Mar  9 11:29:03.233 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is down: retry limit exceeded

Mar  9 11:29:05.917 AEDT: %DUAL-5-NBRCHANGE: EIGRP-IPv4 15: Neighbor 10.108.255.2 (Port-channel1.851) is up: new adjacency

I've read through the various EIGRP troubleshooting guides online but can't narrow it down to what's causing this.

I believe it's a multicast issue somewhere within the network, but not sure how to diagnose where the issue is exactly.

1/ Unicast ping end-to-end works

From 10.108.255.1, we can ping 10.108.255.2 with small and large packet sizes.

Unfortuantely we don't have access to 10.108.255.2 so can't repeat the process the other way.

2/ Multicast ping fails

From 10.108.255.1, doing a multicast ping 224.0.0.10, we don't get any replies from 10.108.255.2 - so I think this is what the issue is.

My question is - how do I check where multicast is failing???

Config:

\\ 10.108.255.1

router eigrp 15

!

address-family ipv4 vrf Internal autonomous-system 15

  redistribute bgp 64655 metric 10000 100 255 1 1500

  network 10.108.255.0 0.0.0.3

  passive-interface default

  no passive-interface Port-channel1.851

!

interface Port-channel1.851

encapsulation dot1Q 851

ip vrf forwarding Internal

ip address 10.108.255.1 255.255.255.252

no ip redirects

no ip unreachables

no ip route-cache

\\ 10.108.255.2

interface FastEthernet0/0

description Connects to 3750:Gi1/0/6

ip address 10.108.255.2 255.255.255.252

speed 100

full-duplex

!

router eigrp 15

redistribute static

redistribute ospf 80 metric 1000 10 255 1 1500

passive-interface Serial0/0.1

network 10.0.0.0

network 157.128.0.0

no auto-summary

eigrp log-neighbor-changes

\\ 3750

interface GigabitEthernet1/0/6

switchport access vlan 851

switchport mode access

load-interval 30

speed 100

duplex full

spanning-tree portfast

Thanks.

Andy

[laureldj1]

I had this problem using 3760 switches.  I found that the default for "system mtu routing" was 1998 in the IOS I was running.  Setting the value to 1500 solved the problem and upgrading the IOS resolved it permanently.

[paul driver]

Hello

I would aggree check you mtu settings for the eigrp relationship

Also

My question is - how do I check where multicast is failing???

access-list 100 permit ip host 10.108.255.1 host 224.0.0.10

debug ip packet detail 100

res

Paul

Please don't forget to rate any posts that have been helpful.

Thanks.

[JohnTylerPearce]

Andy,

Can you run 'debug eigrp packets hello', and verify that multicast update packets are being send and or received on each end?

[irritantz]

Andy, hi

did you resolve this problem

I have the same issue

Every 80 seconds EIGRP is DOWN

Dec 25 15:49:47: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is up: new adjacency

Dec 25 15:51:06: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is down: retry limit exceeded

Dec 25 15:51:07: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is up: new adjacency

Dec 25 15:52:26: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is down: retry limit exceeded

Dec 25 15:52:26: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is up: new adjacency

Dec 25 15:53:46: %DUAL-5-NBRCHANGE: EIGRP-IPv4 101: Neighbor 10.201.0.2 (POS3/0/0) is down: retry limit exceeded

[ehfmind01]

I experienced EIGRP flapping between an 1841 ISR and an 3550 switch.  here is what made the flapping go away! " I added on the 3550 switch the following entry on my interface that my 1841 was trying to talk with: 

"ip information-reply"

sw1#sh run int fa0/1
Building configuration...

Current configuration : 150 bytes
!
interface FastEthernet0/1
 description 1841_ISR
 no switchport
 ip address 10.0.0.2 255.255.255.0
 ip information-reply
 speed 10
 duplex half
end

EIGRP worked correctly following this change.  Hope it helps someone.

[joe.fodor]

Yes thank you. one of my new switches had a system MTU set for jumbo frames and one of my other L3 switches wasnt able to connect because of this. I changed the interface by using ip mtu xxx.

[chaitanya4u86]

Hi, 

I faced this problem when running eigrp over DMVPN tunnel interface. Where the updates are flowing from hub to spoke but spoke is just sending Hellos to hub.

The actual problem is the MTU where I have set MTU to 1400 bytes considering the encryption along with GRE header, but only used GRE.

When I set the MTU to 1476 on both HUB and SPOKE, the issue is resolved.

Please note that this is a lab scenario with 7200 series routers running IOS: Version 15.0(1)M

DMVPN_HUB(config)#interface Tunnel0
DMVPN_HUB(config-if)#ip address 192.168.0.2 255.255.255.0
DMVPN_HUB(config-if)#ip mtu 1400
DMVPN_HUB(config-if)#ip nhrp authentication donttell
DMVPN_HUB(config-if)#ip nhrp map multicast dynamic
DMVPN_HUB(config-if)#ip nhrp network-id 99
DMVPN_HUB(config-if)#tunnel source FastEthernet1/0
DMVPN_HUB(config-if)#tunnel mode gre multipoint
DMVPN_HUB(config-if)#tunnel key 100000

*May 7 14:01:12.211: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.0.4 (Tunnel0) is down: retry limit exceeded
DMVPN_HUB#
*May 7 14:01:13.443: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.0.4 (Tunnel0) is up: new adjacency
DMVPN_HUB#
*May 7 14:02:32.963: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.0.4 (Tunnel0) is down: retry limit exceeded
DMVPN_HUB#
*May 7 14:02:36.307: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.0.4 (Tunnel0) is up: new adjacency

 DMVPN_HUB(config)#int tu0
DMVPN_HUB(config-if)#no ip mtu 1400
DMVPN_HUB(config-if)#ip mtu 1476

DMVPN_HUB#
*May 7 14:26:15.091: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 192.168.0.4 (Tunnel0) is up: new adjacency

DMVPN_HUB#show ip route eigrp
Codes: L - local, C - connected, S - static, R - RIP, M - mobile, B - BGP
D - EIGRP, EX - EIGRP external, O - OSPF, IA - OSPF inter area
N1 - OSPF NSSA external type 1, N2 - OSPF NSSA external type 2
E1 - OSPF external type 1, E2 - OSPF external type 2
i - IS-IS, su - IS-IS summary, L1 - IS-IS level-1, L2 - IS-IS level-2
ia - IS-IS inter area, * - candidate default, U - per-user static route
o - ODR, P - periodic downloaded static route, + - replicated route

Gateway of last resort is not set

1.0.0.0/32 is subnetted, 1 subnets
D 1.1.1.1 [90/156160] via 192.168.12.1, 00:13:49, FastEthernet0/0
3.0.0.0/32 is subnetted, 1 subnets
D 3.3.3.3 [90/27010560] via 192.168.0.4, 00:00:30, Tunnel0
4.0.0.0/32 is subnetted, 1 subnets
D 4.4.4.4 [90/27008000] via 192.168.0.4, 00:00:30, Tunnel0
D 192.168.34.0/24 [90/26882560] via 192.168.0.4, 00:00:30, Tunnel0

[andre2mei]

I got the same issue on my network. but I trying to disable auto-summary and the flapping is disappear.

I don't know what happen!

[manoj.petshali]

Hi all,

I faced this issue while doing DMVPN .

I got the messages as:

 12:22:06.906: %DUAL-5-NBRCHANGE: EIGRP-IPv4 45678: Neighbor  (Tunnel0) is down: retry limit exceeded

12:22:08.521: %DUAL-5-NBRCHANGE: EIGRP-IPv4 45678: Neighbor  (Tunnel0) is down: retry limit exceeded

This was the message at Hub side .

The solution worked was:

"no ip redirects    command on Hub side.

[rifi1]

So here is a quick  solutions,

 if you are using  phase 1:

 enable   static multicast on the hub like :  ip  nhrp map multicast  nmba  

you need to enable on the hub hub for each  spoke.

also try to ping 224.0.0.10 on all the side

[Star Sulaiman]

Great, it solved my issue. thank you

[mainkiller12]

Hello ,

I have same issue with DMVPN,

I cannot ping the the tunnels ip and Lans are not talking each other through DMVPN.

HUB side config bellow:

sh version

Technology Package License Information:

-----------------------------------------------------------------

Technology  Technology-package      Technology-package

       Current    Type      Next reboot

------------------------------------------------------------------

appxk9      None       None       None

uck9       uck9       Permanent    uck9

securityk9    None       None       None

ipbase      ipbasek9     Permanent    ipbasek9

cisco ISR4331/K9 (1RU) processor with 1795999K/6147K bytes of memory.

interface Tunnel35

 description #### DMVPN ####

 ip address 172.16.100.1 255.255.255.0

 no ip redirects

 ip mtu 1476

 no ip next-hop-self eigrp 100

 no ip split-horizon eigrp 100

 ip nhrp authentication cisco123

 ip nhrp network-id 35

 ip nhrp holdtime 60

 ip nhrp registration timeout 30

 ip tcp adjust-mss 1360

 keepalive 2 3

 tunnel source GigabitEthernet0/0/0

 tunnel mode gre multipoint

 tunnel key 1234

!

!

interface GigabitEthernet0/0/0

 description ## ISP##

 ip address 105.174.37.242 255.255.255.248

 ip nat outside

 negotiation auto

 ip virtual-reassembly

!

!

interface GigabitEthernet0/0/1

 description ## LAN ##

 no ip address

 ip nat inside

 negotiation auto

 ip virtual-reassembly

!

interface GigabitEthernet0/0/1.10

 description ## data##

 encapsulation dot1Q 10

 ip address 192.168.10.1 255.255.255.0

 ip nat inside

 ip virtual-reassembly

!

!

router eigrp 100

 network 172.16.0.0

 network 192.168.0.0

!

ip route 0.0.0.0 0.0.0.0 105.174.37.241

!

sh ip eigrp neighbors

EIGRP-IPv4 Neighbors for AS(100)

H  Address         Interface       Hold Uptime  SRTT  RTO Q Seq

                          (sec)     (ms)    Cnt Num

0  172.16.100.2      Tu35           10 00:01:08  1 5000 1 0

!

*Nov 6 10:47:12.075: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 172.16.100.2 (Tunnel35) is down: retry limit exceeded

!

*Nov 6 10:47:15.449: %DUAL-5-NBRCHANGE: EIGRP-IPv4 100: Neighbor 172.16.100.2 (Tunnel35) is up: new adjacency

################

On SPOKE side

SH VERSION

Technology Package License Information:

-----------------------------------------------------------------

Technology  Technology-package      Technology-package

       Current    Type      Next reboot

------------------------------------------------------------------

appxk9      None       None       None

uck9       uck9       Permanent    uck9

securityk9    None       None       None

ipbase      ipbasek9     Permanent    ipbasek9

cisco ISR4321/K9 (1RU) processor with 1795999K/6147K bytes of memory.

interface Tunnel35

 ip address 172.16.100.2 255.255.255.0

 no ip redirects

 ip mtu 1476

 ip nhrp authentication cisco123

 ip nhrp map multicast 105.174.37.242

 ip nhrp map 172.16.100.1 105.174.37.242

 ip nhrp network-id 35

 ip nhrp nhs 172.16.100.1

 ip tcp adjust-mss 1360

 tunnel source GigabitEthernet0/0/1

 tunnel mode gre multipoint

 tunnel key 1234

!

interface GigabitEthernet0/0/0

 description ## LAN ##

 no ip address

 negotiation auto

!

interface GigabitEthernet0/0/0.30

 description ## data ##

 encapsulation dot1Q 30

 ip address 192.168.30.1 255.255.255.0

 ip nat inside

 ip virtual-reassembly

!

!

router eigrp 100

 network 105.0.0.0

 network 172.16.0.0

 network 192.168.0.0

 redistribute static

Not able to ping 172.16.100.1 on the HUB

Can some one please help!

[rifi1]

Please enable multicast on your HUB:

[iulianmorari1995]

It happened to me in an EIGRP lab. The problem was different masks on the interface . One had a /24 and one was /30. So every couple of seconds eigrp would create an adjacency and then drop it .