IpArp not learning IP

[GONÇALO_NUNO_CO]

Hi,

i am trying to troubleshoot why IPARP is not showing the IP addresses of edge devices.
Slot-1 SEDUCA050100.3 # sh iparp stats ports 3:23
IP ARP Port Statistics Thu Mar 8 08:55:47 2018
Port Link State Active ARP Total Dynamic Static
===============================================================================
3:23 A 0 0 0
===============================================================================If i do a "sh fdb port 3:23" i can see the mac of the connected device, but for some reason IPARP is not storing the Mac and the IP address of the connected device, this is hapenning on all ports, also and since IPARP doest not store any IP addresses, IdMgr doesnt show them too.

I have all vlan interfaces configured with an ip address and IPARP is enabled by default on the switch.

I wondering what commands can i use to troubleshoot this situation.

Br,
Gonçalo Reis

[OscarK]

If the vlan IP is not used as default gateway bythe client devices the arp will not be learned by the switch just because it has an IP in the same range.

[OscarK]

I think policy denies or overrules the packet to CPU to learn the arp entry. Did you look into node alias ? That would learn the IP address too and should be a better method. Also XMC will check node alias tables if its enabled.

[GONÇALO_NUNO_CO]

Hi Oscar, thank you for replying. It is my bad for not explaining everything properly. On my network, access switches have a random IP Address outside the network range of each Vlan for each Vlan.

Example:

Vlan servers is assigned with the network range 10.147.254.0/24, the gateway for this Vlan is one of the core switches.

On my access switch i assign the ip address of 172.16.254.1/32 to the vlan servers.

For the access switch to be able to learn the ip address of the end devices, it has to be configured with "disable iparp checking".

I have all my access switches configured this way and this works for all versions of the extreme EXOS, what is happening in version 22.4.1.4 is when i assign a policy rule to an edge port the switch is unable to learn the IP address of the directly connected device and when i remove the policy, it learns the IP address of the end device.

Regards
Gonçalo Reis

[EtherMAN]

Am I missing something here... Show IPARP stats will not show you any ipa addresss and mac information. It show you how many ipa it has learned on the port or vlan...

Slot-2 PLW_X670G2_5959_Stack.5 # sh ipa sta por 1:32
IP ARP Port Statistics Thu Mar 8 08:40:57 2018
Port Link State Active ARP Total Dynamic Static
===============================================================================
p1-32_Nim_Ctrl2_P1 A 2 2 0

Slot-2 PLW_X670G2_5959_Stack.6 # sh ipa sta vlan "PLW_San_595"
IP ARP VLAN Statistics Thu Mar 8 08:41:26 2018
VLAN Active ARP Total Dynamic Static
===============================================================================
PLW_San_595 7 7 0

You need to leave the stats command out to see entries

Slot-2 PLW_X670G2_5959_Stack.7 # sh ipa port 1:32
VR Destination Mac Age Static VLAN VID Port
VR-Default 172.16.59.10 00:e0:ed:2f:5a:c2 2 NO PLW_San_595 595 1:32
VR-Default 172.16.59.11 00:e0:ed:2f:5a:c2 2 NO PLW_San_595 595 1:32

Of course if there are arps that should be learned on the port and are not then you have a different issue.