Hallo Everyone,
i have encountered a very strange situation after updating C9500 Switch using ISSU from version 17.3.4 to 17.09.06. the problem is that the hosts of a privat vlan (used for OOB Management)is not reachable anymore. even though the the MAC addresses are learnt on the Distribution Switch where the SVI resides. we see an INCOMPLETE Arp entry.
Topology is like This:
Host (Nexus Switch)---->Access switch (c2960x)---->Distribution Switch (C9500)
we did wireshark capture on both ends, run ping to the default gateway of Nexus Switch (SVI Interface). ARP request are send and recived on Distribution Switch. the problem is that Ping doesnt work. i did an Embeded Packet Capture on Distribution switch to make sure that ICMP requests are reaching the switch and it shows that icmp requests are comming but the Destribution Switch doesnt send back ICMP replies.
no Change on the Switch configuration has been done, only IOS update.
unfortunately i cannot paste the complete config here. would really appreciate any tip/advise bevore opening a TAC Case.
Thanks.
