topic Re: ARP RESPONSE collision in Application Networking

ARP RESPONSE collision

blankguy7 — Mon, 16 Apr 2012 06:57:07 GMT

Hi,

I've configured two ACE appliances with redundance (fault-tolerance VLAN).

Since the following messages appears on ACE's :

Apr 15 2012 14:43:59 : %ACE-4-405001: Received ARP RESPONSE collision from 192.168.10.253 e8.9a.8f.b2.68.7a on interface vlan100

Apr 15 2012 14:44:03 : %ACE-4-405001: Received ARP RESPONSE collision from 192.168.10.253 e8.9a.8f.b2.68.7a on interface vlan100

Apr 15 2012 14:44:05 : %ACE-4-405001: Received ARP RESPONSE collision from 192.168.10.253 e8.9a.8f.b2.68.7a on interface vlan100

Apr 15 2012 14:44:07 : %ACE-4-405001: Received ARP RESPONSE collision from 192.168.10.253 e8.9a.8f.b2.68.7a on interface vlan100

Apr 15 2012 14:44:09 : %ACE-4-405001: Received ARP RESPONSE collision from 192.168.10.253 e8.9a.8f.b2.68.7a on interface vlan100

ACE1/GAAS# sh arp

Context GAAS

================================================================================

IP ADDRESS MAC-ADDRESS Interface Type Encap NextArp(s) Status

================================================================================

192.168.10.1 00.1f.9f.f1.a9.a1 vlan100 GATEWAY 10 43 sec up

192.168.10.246 e8.9a.8f.b2.68.80 vlan100 INTERFACE LOCAL _ up

192.168.10.250 e8.9a.8f.b2.68.80 vlan100 VSERVER LOCAL _ up

192.168.10.253 e8.9a.8f.b2.68.80 vlan100 NAT LOCAL _ up

================================================================================

ACE2/GAAS# sh arp

Context GAAS

================================================================================

IP ADDRESS MAC-ADDRESS Interface Type Encap NextArp(s) Status

================================================================================

192.168.10.1 00.1f.9f.f1.a9.a1 vlan100 GATEWAY 11 86 sec up

192.168.10.247 e8.9a.8f.b2.68.7a vlan100 INTERFACE LOCAL _ up

192.168.10.250 e8.9a.8f.b2.68.7a vlan100 VSERVER LOCAL _ up

192.168.10.253 e8.9a.8f.b2.68.7a vlan100 NAT LOCAL _ up

================================================================================

Total arp entries 4

Has someone an Idea?

Thanks in advance

ARP RESPONSE collision

Surya ARBY — Mon, 16 Apr 2012 07:56:05 GMT

Can you show us the config of the admin context ?

Have you allocated mac address pools with different numbers ?

shared-vlan-hostid / peer shared-vlan-hostid

Re: ARP RESPONSE collision

blankguy7 — Mon, 16 Apr 2012 08:00:18 GMT

sure, here's the admin context configuration :

ACE1/Admin# sh run

Generating configuration....

logging enable

logging buffered 4

logging queue 2000

boot system image:c4710ace-t1k9-mz.A5_1_2.bin

hostname ACE1

interface gigabitEthernet 1/1

shutdown

interface gigabitEthernet 1/2

switchport access vlan 100

no shutdown

interface gigabitEthernet 1/3

shutdown

interface gigabitEthernet 1/4

switchport access vlan 200

no shutdown

ft interface vlan 200

ip address 10.1.1.2 255.255.255.0

peer ip address 10.1.1.3 255.255.255.0

no shutdown

ft peer 1

heartbeat interval 300

heartbeat count 10

ft-interface vlan 200

ft group 1

peer 1

priority 150

associate-context Admin

inservice

context GAAS

allocate-interface vlan 100

username admin password 5 $1$449pMeGu$NwD2lPttjANuMq/gxgv4A1 role Admin domain

default-domain

username www password 5 $1$w43pZtK3$ZllEobQFqTbdYWQl2V3.n0 role Admin domain de

fault-domain

ssh key dsa 1024 force

No, I've don't allocated mac address pools? Should I do that?

Re: ARP RESPONSE collision

Surya ARBY — Mon, 16 Apr 2012 08:08:33 GMT

Yep.

Also can you give us the output of the "show ft group detail" ?

Re: ARP RESPONSE collision

blankguy7 — Mon, 16 Apr 2012 08:10:46 GMT

Here's :

ACE1/Admin# sh ft group detail

FT Group : 1

No. of Contexts : 1

Context Name : Admin

Context Id : 0

Configured Status : in-service

Maintenance mode : MAINT_MODE_OFF

My State : FSM_FT_STATE_ACTIVE

My Config Priority : 150

My Net Priority : 150

My Preempt : Enabled

Peer State : FSM_FT_STATE_STANDBY_HOT

Peer Config Priority : 100

Peer Net Priority : 100

Peer Preempt : Enabled

Peer Id : 1

Last State Change time : Fri Apr 13 14:52:15 2012

Running cfg sync enabled : Enabled

Running cfg sync status : Running configuration sync has completed

Startup cfg sync enabled : Enabled

Startup cfg sync status : Startup configuration sync has completed

Connection sync enabled : Enabled

Bulk sync done for ARP : 0

Bulk sync done for LB : 0

Bulk sync done for ICM : 0

Bulk sync done for ND : 0

Re: ARP RESPONSE collision

Surya ARBY — Mon, 16 Apr 2012 08:19:14 GMT

strange, you have different mac addresses on both units. The standby unit should never reply to arp requests

Re: ARP RESPONSE collision

blankguy7 — Mon, 16 Apr 2012 08:25:05 GMT

Now I've configure the following on the Admin context :

shared-vlan-hostid 1

peer shared-vlan-hostid 2

But I don't think that it's make something different?

ACE1/GAAS# sh arp

Context GAAS

================================================================================

IP ADDRESS MAC-ADDRESS Interface Type Encap NextArp(s) Status

================================================================================

192.168.10.1 00.1f.9f.f1.a9.a1 vlan100 GATEWAY 10 133 sec up

192.168.10.88 00.27.13.b8.d1.e0 vlan100 LEARNED 14 14233 sec up

192.168.10.246 e8.9a.8f.b2.68.80 vlan100 INTERFACE LOCAL _ up

192.168.10.250 e8.9a.8f.b2.68.80 vlan100 VSERVER LOCAL _ up

192.168.10.253 e8.9a.8f.b2.68.80 vlan100 NAT LOCAL _ up

================================================================================

Total arp entries 5

ACE2/GAAS# sh arp

Context GAAS

================================================================================

IP ADDRESS MAC-ADDRESS Interface Type Encap NextArp(s) Status

================================================================================

192.168.10.1 00.1f.9f.f1.a9.a1 vlan100 GATEWAY 11 293 sec up

192.168.10.247 e8.9a.8f.b2.68.7a vlan100 INTERFACE LOCAL _ up

192.168.10.250 e8.9a.8f.b2.68.7a vlan100 VSERVER LOCAL _ up

192.168.10.253 e8.9a.8f.b2.68.7a vlan100 NAT LOCAL _ dn

================================================================================

Total arp entries 4

Thanks for your help!

Re: ARP RESPONSE collision

Surya ARBY — Mon, 16 Apr 2012 08:27:21 GMT

Open a case, I don't know why the second ACE sends ARP messages.

Re: ARP RESPONSE collision

blankguy7 — Mon, 16 Apr 2012 08:35:28 GMT

Thanks a lot for your help!

Ok, I'll open a case...

Re: ARP RESPONSE collision

Surya ARBY — Mon, 16 Apr 2012 08:42:58 GMT

Is there any impact on the service ? Arp collisions in L2 adjacent devices ?

Maybe this issue is purely cosmetic.

Re: ARP RESPONSE collision

blankguy7 — Tue, 17 Apr 2012 08:22:12 GMT

Hi Surya,

So, I've open a case by Cisco... and we've found the solution to my problem!

To help the communities I put the solution here :

I've configure one ft group for the Admin context and for the vlan in Admin context all was good!

But I've a another context and I don't have configure a ft group for this context and that was the problem...

Each context should be or must be defined by one ft group.

That's it

Best regards