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VLT - ARP table is not syncing
Hi all ,
am using OS version 9.14(2.6) hardware Z9100-ON with VLT peer routing .
both switch's dynamic routing enabled
my doubt is my ARP table is not same on both switch - example vlan 10 sw1 having 10 arp entry and sw2 having 7 entry .
both switch having VLAN 10 - L3 interface , and interface IP i can see on both switch .
and mac table and cam table also matching ( except VLAN10 static IP address - on both CAM table respective VLAN IP address mac only learned , other all detail is matching on both cam table )
My Doubt is in VLT ARP table will sync between switch ?
if above answer is yes , then why ARP is missing in one switch ?
is there is site available in dell to know about -known buggs ?
Hi,
i have doubt about state sync between switches , in the syncing IP address ( arp table will sync ) between switches ?
normally in the cisco VPC , aruba VSX both arp table normally same .
is there is command available to debug state packet between VLT switches ?
DELL-Erman O
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Posted February 16th, 2023 04:00
Hi, I'm not aware of a specific command to debug state packets between VLT switches. I saw debug ip packets cmd in reference guide for S5048F https://dell.to/3jUMpgE
I checked from here, if I didn't miss it, please take a look. https://dell.to/3YP2UJI
DELL-Erman O
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I disabled Layer3 interface ( VLAN ) and enabled the interface . after that i can see that both switch having same number of AP entry .
but after ARP Timeout in sw2 arp entry is missing .
in the configuration gratuitous arp enabled ,arp learn-enable .
the arp entry missing in VRRP backup router is there is command available in VRRP configuration to sync arp table between master and backup
DELL-Joey C
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Posted February 26th, 2023 21:00
Hi @PD-Dell,
Are you referring to VLT unicast routing? https://dell.to/41xRzAa.
Perhaps, I may suggest that if the configurations are not as expected to be running, a support case need to be created by calling the support line. It would be best to check the switch's configurations and your network needs.
DELL-Joey C
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DELL-Joey C
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Posted February 16th, 2023 00:00
Hi @PD-Dell,
This is normal when you are configuring both active-active as both switches are doing L3 routing. I've read roughly through some guide, it stated that this will cause Split-Brain scenario which may lead to your ARP table displaying different entries. I'm attaching the VLT L3 architecture reference guide: https://dell.to/3XEkbnU
Also, a small explanatory of VLT Split-Brain scenario, page 14: https://dell.to/3XzNsQE
DELL-Joey C
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