ARP issues

[fanatic1217]

I have a 4507 R+E switch trunking thru a leased fiber line to a 3650 48port non poe Switch.

We have been having inconsistent ARP related issues. Currently, I have to static ARP any IP's that are directly connected to, or reside on, the 3650 switch, onto the 4507 switch. Also, in order to ping from my pc (a device that is on the 4507 side of the network) to any device directly connected to the switch(on the same vlan as my pc) I have to first ping from that device to my pc or apply a static arp rule on my pc. Then I can ping from my pc. I am beyond puzzled at this network and how to fix or even troubleshoot these ARP issues. We are running the preferred IOS for each of these switches as we have just upgraded them. Again, anything that is not directly connected to that switch operates as it is supposed to. However, any IP address that resides on the 3650 switch is unreachable without a static ARP or first sending icmp from that ip address to the 4507 device.

The 4507 device has many other trunking ports and all of the others work properly.

HELP?!?!?!?!?!?!

[Reza Sharifi]

Since this is only happening on the fiber leased line, have you talk to the provider about this?

[fanatic1217]

No. Not yet. However, there are many other connections on that utilize that same leased line that are unfazed. I would like to eliminate all other possibilities before calling them as they are just going to ask me if I have.

[dronkin2007]

Could you please, try different OS on your computers (connected to the network in question/the same Vlan). How they PC communicate to each other...

Let say Linux to Linux, WinXP to WinXP, Win7 to Win7. It is possible that through the patching process, Microsoft enhanced security and "external" command (which arp.exe is) is not available anymore. For Linux, it would not be a problem for example.

I suspect that current PCs do not have problem to communicate outside of Vlan?

Regards,

Dimo

[fanatic1217]

Talked to ISP, we are dropping many broadcast packets on the 3650 side of the ISP, this is because there is no router in between the switches to break up the broadcast domain. We also got 2 more 3650 switches to set them up as the current switches are set up and they too have ARP issues. Most likely this is a config issue coupled with a broadcast issue. Will update when I find what config is causing the problem with the ARP. If anyone has any idea as to where to check for that, would be most appreciated.

[fanatic1217]

Finally figured out why the ARP issues were taking place. There was a setting on the trunk on the 3650 switch that was suppressing broadcasts. I don't know how it took so long to find, but I found it none-the-less.

The setting was "storm-control broadcast level 0.0".

There was also a "storm-control multicast level 0.0"