ping router's ip Destination host unreahable in the same subnet

[Taylor Xu]

PC and router are on the same subnet，pc1 ping the router returns  Destination host unreachable。change the mac address of pc，ping was ok。

all switch has no acl、802.1x and port security；

the router has no acl configuration。

The cisco 24s is Core Switch, vlan 10 interface ip is 192.168.16.250.   ping 192.168.16.250 was ok.  ping the router's ip was failed.

Can somebody help me？ 

[Taylor Xu]

Suddenly one day it doesn't work, it seems that some policies are triggered, causing these mac addresses to be blocked.
However, neither the switch nor the router is configured with relevant security configurations.
There is also no firewall in the entire link.

Any idea？

[MHM Cisco World]

show 
show interface trunk for both SW

[Taylor Xu]

CoreSW：

DC-Core-Cisco-3850-1#show interfaces trunk

Port Mode Encapsulation Status Native vlan
Po1 on 802.1q trunking 1
Po2 on 802.1q trunking 1
Po10 on 802.1q trunking 1
Po11 on 802.1q trunking 1
Po12 on 802.1q trunking 1
Po13 on 802.1q trunking 1
Po14 on 802.1q trunking 1
Po15 on 802.1q trunking 1
Po16 on 802.1q trunking 1
Po17 on 802.1q trunking 1
Po18 on 802.1q trunking 1

Port Vlans allowed on trunk
Po1 1-4094
Po2 1-4094
Po10 1-4094
Po11 1-4094
Po12 1-4094
Po13 1-4094
Po14 1-4094
Po15 1-4094
Po16 1-4094
Po17 1-4094
Po18 1-4094

DC-Core-Cisco-3850-1#show mac address-table | include 928b
10 a08c.fdcb.928b DYNAMIC Po11
DC-Core-Cisco-3850-1#

AccessSW：

UG01c-SW-HotelO-2960#show interfaces trunk

Port Mode Encapsulation Status Native vlan
Po1 on 802.1q trunking 1

Port Vlans allowed on trunk
Po1 1-4094

Port Vlans allowed and active in management domain
Po1 1,10

Port Vlans in spanning tree forwarding state and not pruned
Po1 1,10
UG01c-SW-HotelO-2960#show mac add
UG01c-SW-HotelO-2960#show mac address-table | include 928b
10 a08c.fdcb.928b DYNAMIC Gi1/0/6
UG01c-SW-HotelO-2960#

[MHM Cisco World]

show etherchannel summary for both SW 
show vlan 
show interface x/x switchport for both SW <<- the x/x is one port member of Port channel 

[Taylor Xu]

Here are some configuration of SWs and router, real configuration.

[Taylor Xu]

Hi,MHM,Thanks for your reply,I left first, please leave a message if you have any ideas, I will reply as soon as I see it, thanks again.

attach is wireshar capture of pc  when ping the router。

[Harold Ritter]

Hi @Taylor Xu ,

I am not sure where the packet capture was taken from, but it does not contain any information about 192.168.16.10 and 192.168.16.254 mentioned in the original message.

Can you please verify.

Regards,

[Taylor Xu]

,sorry, ip addr. in diagram jjust for examp，the true ip address of pc is
172.24.16.169 and the router's ip is 172.24.16.254.

[MHM Cisco World]

I check the wireshark capture you share '

I See arp and icmpv6 

Check if pc have ipv4 

And if it have ipv4 then share output of above command I request before.

Thanks 

MHM

[Taylor Xu]

in production env,the PCs ip addr. is 172.24.16. 169 and the router's ip is
172.24.16.254
PC's mac is:a08c.fdcb.928b
router's mac is :00f2.8b31.6a01

[MHM Cisco World]

Everything is correct, 

PO is Up and port member is P 

But still only one point confused me 

When you sharing show interface trunk

The output don't have any indication about allow and active vlan in trunk? Did you post all output? 

[Taylor Xu · Accepted solution]

Hi, MHM,Thank you very much!The problem has already solved.everything is correct,finally,i rebooted the core switch,everyting was back to nomal.  

Thanks again!

[MHM Cisco World]

Glad issue is solved'

Happy ending 

I Was thinking' to ask you reboot but I stop since there is many PO in core i.e. whole network will be down.

But you smarter and faster than me and do correct step

Have a nice weekend 

MHM