Showing results for 
Search instead for 
Did you mean: 

Communication loss with Router


Bear with me as I am a beginner and might not be using correct terminology. I have a new issue as of this week where I cannot communicate with another subnet from 1 of my 10 workstations. Basically we have 2 networks, A (10.13.153) and B(10.13.154) connected by a 3850 router.  There are 10 workstations in each network.  Every workstation in A can communicate with every workstation in B.  All of the sudden one 1 of my workstations in network A cannot communicate with network B.  Everything else is working fine.  Every other station can communicate with every other station.  The workstation in question can communicate with the other 9 workstations in network A but cannot even ping the router.  If I change the IP address of this 1 station, everything starts to work fine.  If I change it back to the original IP, it stops working again. No changes have been made at all.  I feel like it has to be something in the router but have no idea what to look for.  There are no IP specific ACL’s configured in the router.  Any direction is appreciated.

10 Replies 10

VIP Advisor VIP Advisor
VIP Advisor

Hi @DerekRhodes64553 


Can you share the network parameters configured on the workstation with problems?
Assigned IP
You could also share the parameters configured in the router's interface.




In addition to the items requested by @luis_cordova would you also provide these:

- the mac address of the PC that has the problem. (probably the output of ipconfig would be the easy way but you could also get it by show mac address table on the 3850 and look for the mac address on the port that connects to that PC).

- the IP address on the PC when it has the problem.

- the IP address on the PC when you change the address and it works.

- the output of show arp on the 3850.



Mac Address:  00:0A:F7:82:73:AA

IP w/Problem:

IP wo/Problem:

ARP Output:

Protocol  Address          Age (min)  Hardware Addr   Type   Interface
Internet             -   0000.0c07.ace7  ARPA   Vlan301
Internet             -   00b1.e33c.44e2  ARPA   Vlan301
Internet           145   00d6.fe51.6f62  ARPA   Vlan301
Internet         243   509a.4c9f.e24c  ARPA   Vlan301
Internet           1   509a.4c76.66fd  ARPA   Vlan301
Internet           0   b026.28c4.14ae  ARPA   Vlan301
Internet           1   6c2b.59ae.2968  ARPA   Vlan301
Internet           5   fc5b.392d.b788  ARPA   Vlan301
Internet            0   246e.968b.1728  ARPA   GigabitEthernet1/0/2
Internet            0   246e.968b.3a4c  ARPA   GigabitEthernet1/0/2                                             
Internet            0   246e.968b.17d0  ARPA   GigabitEthernet1/0/2                                      
Internet            0   000a.f782.73aa  ARPA   GigabitEthernet1/0/2                                         
Internet            0   246e.968b.3ad4  ARPA   GigabitEthernet1/0/2                                  
Internet            0   246e.968a.4630  ARPA   GigabitEthernet1/0/2                                       
Internet            0   246e.9678.f730  ARPA   GigabitEthernet1/0/2                                      
Internet           24   847b.ebf0.ee5a  ARPA   GigabitEthernet1/0/2                                    
Internet          123   847b.ebf0.ee69  ARPA   GigabitEthernet1/0/2                             
Internet            2   847b.ebf0.f0b0  ARPA   GigabitEthernet1/0/2                                       
Internet          166   847b.ebf0.edb0  ARPA   GigabitEthernet1/0/2                 
Internet           0   509a.4c69.b54b  ARPA   GigabitEthernet1/0/2                                      
Internet           0   d094.6605.601d  ARPA   GigabitEthernet1/0/2                           
Internet           0   d094.6605.5e2e  ARPA   GigabitEthernet1/0/2                                     
Internet          76   6c2b.5986.011e  ARPA   GigabitEthernet1/0/2                                     
Internet         170   f8b7.e262.ebe9  ARPA   GigabitEthernet1/0/2                                     
Internet          80   b4a8.b9fe.5542  ARPA   GigabitEthernet1/0/2                                     
Internet         167   b4a8.b9fe.7cc2  ARPA   GigabitEthernet1/0/2                                    
Internet           3   6cdd.3035.83c2  ARPA   GigabitEthernet1/0/2                                       
Internet           2   6cdd.3035.3042  ARPA   GigabitEthernet1/0/2                                        
Internet           -   00b1.e33c.44d6  ARPA   GigabitEthernet1/0/2                                    
Internet           -   0000.0c07.ac65  ARPA   GigabitEthernet1/0/2                                
Internet            0   246e.9678.fe4c  ARPA   GigabitEthernet1/0/3                                         
Internet            0   246e.9678.ebbc  ARPA   GigabitEthernet1/0/3                                     
Internet            0   246e.9678.f640  ARPA   GigabitEthernet1/0/3                           
Internet            0   000a.f782.73b2  ARPA   GigabitEthernet1/0/3                           
Internet            0   246e.968a.4674  ARPA   GigabitEthernet1/0/3                                 
Internet            0   246e.968b.4014  ARPA   GigabitEthernet1/0/3                         
Internet            0   246e.968a.43ec  ARPA   GigabitEthernet1/0/3                        
Internet          156   847b.ebf0.ed7b  ARPA   GigabitEthernet1/0/3                                         
Internet          257   847b.ebf0.f0b9  ARPA   GigabitEthernet1/0/3                              
Internet          171   847b.ebf0.f082  ARPA   GigabitEthernet1/0/3                                   
Internet          103   0080.64f5.debe  ARPA   GigabitEthernet1/0/3                              
Internet           0   509a.4c69.b4b3  ARPA   GigabitEthernet1/0/3                           
Internet           0   d094.6605.5d1b  ARPA   GigabitEthernet1/0/3                             
Internet           0   d094.6605.635d  ARPA   GigabitEthernet1/0/3                     
Internet           0   6c2b.5986.03c6  ARPA   GigabitEthernet1/0/3      
Internet           8   9c93.4e65.9465  ARPA   GigabitEthernet1/0/3                          
Internet          64   f8b7.e262.ea7d  ARPA   GigabitEthernet1/0/3                 
Internet          63   ec1d.8b19.577d  ARPA   GigabitEthernet1/0/3                         
Internet          71   b4a8.b9fe.78c2  ARPA   GigabitEthernet1/0/3                           
Internet          51   b4a8.b9fe.7c42  ARPA   GigabitEthernet1/0/3                         
Internet           4   6cdd.3035.61c2  ARPA   GigabitEthernet1/0/3                         
Internet          14   6cdd.3034.d742  ARPA   GigabitEthernet1/0/3                           
Internet           -   00b1.e33c.44d8  ARPA   GigabitEthernet1/0/3                                     
Internet           7   00d6.fe51.6f58  ARPA   GigabitEthernet1/0/3                                      
Internet           -   0000.0c07.ac66  ARPA   GigabitEthernet1/0/3    


Thank you for the additional information. Can you help us understand the network a bit better. When you described 2 networks connected by 3850 I assumed that the devices in the networks were connected to the 3850. But the arp output shows that every device in the 10.13.153 network is connected through Gig1/0/2. So what is connected to Gig1/0/2? I am also interested in the fact that the interface is configured with HSRP. Does this mean that there is a second layer 3 device routing for this network? Can you tell us more about this other device?  Also can you tell us whether the PCs are learning their IP via DHCP or are they manually configured?


You tell us that when configured with .54 the PC can not ping the router. Is the PC attempting to ping the interface address or to ping the HSRP virtual address?


Also would you perform this test:

- configure the PC with .54

- attempt to ping the router

- attempt to ping the other network

- do arp -a and post the output

- configure the PC with .59

- attempt to ping the router

- attempt to ping the other network

- do arp -a and post the output



You are correct.  There is a 2nd router but it is identical.  Every switch and router in the network is redundant and there are 2 nic cards on every station.  This is a process network in an industrical facility.  The network is set up in what Honeywell calls FTE, or fault taulerant ethernet.  Basically you can lose any 1 device/connection and still maintain communication.  All of the stations in each network are connected to a layer 2 switch and the layer 2 switch is connected to Gig0/1/2.  FYI, I can ping the layer 2 switch. 

When I have been attempting to ping the router is has been with the address which is what we have configured for the DG.  No DHCP.  Everything is static. 

Thanks for the additional information. I suggested some steps for additional testing. I would add to them a suggestion that when you attempt to ping the router that you try both the HSRP virtual address (254) but also try the interface IP address.



Assigned IP:




Switch Interface:

interface GigabitEthernet1/0/2
 description TO COBRBBSW1Y
 no switchport
 ip address
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip pim dense-mode
 standby 101 ip
 standby 101 timers 2 6
 standby 101 priority 105
 standby 101 preempt delay minimum 90
 standby 101 track 2 decrement 10
 standby 101 track 4 decrement 10
interface GigabitEthernet1/0/3
 description TO LIBRBBSW1Y
 no switchport
 ip address
 no ip redirects
 no ip unreachables
 no ip proxy-arp
 ip pim dense-mode
 standby 102 ip
 standby 102 timers 2 6
 standby 102 priority 105
 standby 102 preempt delay minimum 90
 standby 102 track 1 decrement 10
 standby 102 track 4 decrement 10


When I change IP to then I can ping to router

paul driver
VIP Expert VIP Expert
VIP Expert


@DerekRhodes64553 wrote:

 If I change the IP address of this 1 station, everything starts to work fine.  If I change it back to the original IP, it stops working again. No changes have been made at all. 

Is it possible you have a duplicate ip address for this host?

If it a windows host, you can reset its ip stack and winsock api and reboot it, to see if its clears your issue.


windows host pc
netsh interface ipv4 reset reset.log

netsh winsock reset reset.log
shutdown -r -f -t 10

Please rate and mark as an accepted solution if you have found any of the information provided useful.
This then could assist others on these forums to find a valuable answer and broadens the community’s global network.

Kind Regards

So it's working again but I didn't really do anything.  I changed the IP to .59 for some testing and left it there for a day.  When I put it back to .54 it is now working all of the sudden.  Any ideas

Interesting that it is now working again. From my perspective my first guess at the problem would be that some other device was using the .54 address. I also wonder about the possibility that something in the FTE environment was out of sync and caused it. But we do not know enough about that environment to be able to help.


Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Recognize Your Peers