Invalid arps received from GS724Tv4 ProSafe 24-port Gigabit Ethernet Smart Switch

[phpfan]

The switch is configured with four ports (ports 9 - 12) for VLAN 114. Port 24 is configured as a trunk port used for uplink to a router.

VLAN Status

114

B5-K05 VLAN 114

Static

g9 - g12, g23 - g24

VLAN Membership

9 10 11 12 24

T T  T    T  T

Interface PVID                 VLAN    VLAN

                                       member  tag                       Ingres filtering     Port priority

g9

114

114

114

114

Admit All

Enable

Enable

0

Each port is patched via a patch panel to a RJ45 wall socket

When I connect a Windows machine access to other devices on the local subnet is ok, and internet access is ok

Then comes the issue:

When I connect a PC running Linux or a Mac local arp table shows invalid entry where default GW (accessible though the switch) IP address have a mac address of 00:00:00:00:00:00

Obviousely the Linux or Mac can't communicate since there is no valid destination mac addresss to send the IP packets.

I hope to get help to resolve this

[DaneA · Accepted solution]

Hi phpfan,

Kindly answer the questions below:

a. The devices connected on ports 9-12 of  VLAN114, are they all PCs (PCs running either Windows, MAC or Linux)?   If yes, then ports 9-12 of VLAN114 should be all untagged (U).

b. What is the current firmware version of the GS724Tv4?

c. Have you tried to reboot the PCs running on Linux and MAC while connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

d. What is the behavior/color of the port LEDs of ports 9-12 of VLAN114 when the PCs running on Linux and MAC while connected to it?  

e. Does the PCs running on Linux and MAC connected to ports 9-12 of  VLAN114 have static IP addresses?

f. Have you tried to reboot the GS724Tv4 while the PCs running on Linux and MAC are connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

g. Does same problem occur if you connect the PCs running on Linux and MAC on other VLANs?

h. Does same problem occur if you connect the PCs running on Linux and MAC directly to the router?

i. Is the router a Netgear device also?  If yes, what is the model number of it?

j. Have you tried to reset the GS724Tv4 back to factory default settings then reconfigure it from scratch?

I look forward to your response.  Welcome to the community! 

Regards,

DaneA

Netgear Community Team

[DaneA · Accepted solution]

Hi phpfan,

Kindly answer the questions below:

a. The devices connected on ports 9-12 of  VLAN114, are they all PCs (PCs running either Windows, MAC or Linux)?   If yes, then ports 9-12 of VLAN114 should be all untagged (U).

b. What is the current firmware version of the GS724Tv4?

c. Have you tried to reboot the PCs running on Linux and MAC while connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

d. What is the behavior/color of the port LEDs of ports 9-12 of VLAN114 when the PCs running on Linux and MAC while connected to it?  

e. Does the PCs running on Linux and MAC connected to ports 9-12 of  VLAN114 have static IP addresses?

f. Have you tried to reboot the GS724Tv4 while the PCs running on Linux and MAC are connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

g. Does same problem occur if you connect the PCs running on Linux and MAC on other VLANs?

h. Does same problem occur if you connect the PCs running on Linux and MAC directly to the router?

i. Is the router a Netgear device also?  If yes, what is the model number of it?

j. Have you tried to reset the GS724Tv4 back to factory default settings then reconfigure it from scratch?

I look forward to your response.  Welcome to the community! 

Regards,

DaneA

Netgear Community Team

[phpfan]

Hi,

Thank you for your response and for welcoming me!

a. The devices connected on ports 9-12 of  VLAN114, are they all PCs (PCs running either Windows, MAC or Linux)?   If yes, then ports 9-12 of VLAN114 should be all untagged (U).

Yes, they are all PCs running Windows, OSX or Linux. I will change the ports 9-12 to untagged and test.

b. What is the current firmware version of the GS724Tv4?

6.3.1.9

c. Have you tried to reboot the PCs running on Linux and MAC while connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

No, but I will try changing the ports to U first

d. What is the behavior/color of the port LEDs of ports 9-12 of VLAN114 when the PCs running on Linux and MAC while connected to it?  

I will check.

e. Does the PCs running on Linux and MAC connected to ports 9-12 of  VLAN114 have static IP addresses?

They have dynamic IP addresses. But, I have tested with static IP addresses, and that did not help (since ARP table entry i invalid)

f. Have you tried to reboot the GS724Tv4 while the PCs running on Linux and MAC are connected to ports 9-12 of  VLAN114?  If yes, does same problem occur?

g. Does same problem occur if you connect the PCs running on Linux and MAC on other VLANs?

Yes, and they are configured similar to ports 9-12

h. Does same problem occur if you connect the PCs running on Linux and MAC directly to the router?

No, then it works

i. Is the router a Netgear device also?  If yes, what is the model number of it?

Fortnet Fortigate 90D

j. Have you tried to reset the GS724Tv4 back to factory default settings then reconfigure it from scratch?

No

[phpfan]

Thank you DaneA!

Configuring the ports as untagged solved the problem.

However:

From the Software Administration Manual:

"Tagged. Frames transmitted from this port are tagged with the port VLAN ID

Untagged. Frames transmitted from this port are untagged"

Since the traffic coming in to these ports is forwarded to an outbound router I concluded tagging was required.

And I'm still wondering why PCs wih Windows worked without any issues, while Linux and MAC does not.

With best regards

phpfan

[DaneA]

Hi phpfan,

I am glad that setting the ports as untagged has solved the problem. 

Computers are VLAN-unaware devices that is why the ports should be untagged.  Port(s) should be tagged if ever it is connected to another switch as trunk port or if its connected to VLAN-aware devices such as VoIP phones.

Regards,

DaneA

NETGEAR Community Team