I have 2 stacks N4032F (interstack links 4x10GE) connected by 4x10GE LACP mode active. This is core. Some Cisco switches are connected to them on LACP 2x10GE

I can not ping some hosts from one side to another. This issue is observed when I test from Dell, but also host to host.

I noticed that if is not pingable ARP adge grows. It looks like not ARP are transfered by LACP. All tested hosts are in the same VLAN. Dell switches have interfaces in that vlan where pinged hosts are. When I added static ARP I can ping. When I remove static after some minuts communication breaks. It is observed only pinging some hosts located on Microsoft HV.

----172.16.0.150 PING statistics----
4 packets transmitted, 0 packets received, 100% packet loss
round-trip (msec) min/avg/max = <10/<10/<10

N4032F_1_DC1#show arp

Static ARP entries are only active
when the IP address is reachable on a local subnet


Age Time (seconds)............................. 1200
Response Time (seconds)........................ 1
Retries........................................ 4
Cache Size..................................... 4096
Dynamic Renew Mode ............................ Enable
Total Entry Count Current / Peak .............. 71 / 105
Static Entry Count Configured / Active / Max .. 0 / 0 / 128

IP Address       MAC Address        Interface       Type      Age
---------------  -----------------  --------------  --------  -----------
172.16.0.2       F8B1.567D.8D9E     Vl1             Local         n/a
172.16.0.3       F8B1.567D.8D9A     Vl1             Dynamic    0h  1m  2s
172.16.0.4       085B.0EBD.7896     Vl1             Dynamic    0h  0m  2s
172.16.0.100     0015.5D05.1106     Vl1             Dynamic    0h  0m  0s
172.16.0.111     A4BA.DBF8.B1BF     Vl1             Dynamic    0h  0m  6s
172.16.0.150     0015.5D05.1103     Vl1             Dynamic    0h  1m  5s

I made some tests. First I closed on of legs on LACK to Cisco switches.

Then I started to test stack1 to stack2 4x10GE link closing links. When I had only one link communications works fine. When I had 2 links do different stack members the problem persist, when I had 2 links connecting each stack member horisontally in seems to be OK.

Does anybody have such problems? How can I solve this issu. I need 4x10 interstack link. I havent test 2x2 horizontaly, because at the moment I can only do it remotely.