Hello, All

we are having problem reconnecting two esx5.5 hosts from 5.5 vcenter to 6.5.  this is the error:

Cannot contact the specified host (esxihost). The host may not be available on the network, a network configuration problem may exist, or the management services on this host may not be responding.

tcpdump during connection shows that bidirectional communication is going, but host is failing to connect.

here is the part of tcpdump output

    esxihost.https > vcenter_IP.39982: Flags [P.], cksum 0xe709 (incorrect -> 0xdd79), seq 0:1446, ack 1, win 128, length 1446
10:32:06.302107 IP (tos 0x0, ttl 64, id 34853, offset 0, flags [DF], proto TCP (6), length 1486)
    esxihost.https > vcenter_IP.44320: Flags [P.], cksum 0xe709 (incorrect -> 0xecad), seq 0:1446, ack 1, win 128, length 1446
10:32:57.322334 IP (tos 0x0, ttl 64, id 35341, offset 0, flags [DF], proto TCP (6), length 1486)
    esxihost.https > vcenter_IP.39982: Flags [P.], cksum 0xe709 (incorrect -> 0xdd79), seq 0:1446, ack 1, win 128, length 1446
10:33:10.312389 IP (tos 0x0, ttl 64, id 35434, offset 0, flags [DF], proto TCP (6), length 1486)
    esxihost.https > vcenter_IP.44320: Flags [P.], cksum 0xe709 (incorrect -> 0xecad), seq 0:1446, ack 1, win 128, length 1446

could you please suggest smth here?

thanks in advance