asked on

Unable to ping a server in the same subnet

Hello Experts,

I’m having issues with one server (ServerM) communicating with another server(DC13) in the same subnet. Here is a summary of my environment:
Subnet: 192.168.101.0/24
ServerM: IP = 192.168.101.103
       SM = 255.255.255.0
       DG = 192.168.101.254

DC13: IP = 192.168.101.17
       SM = 255.255.255.0
       DG = 192.168.101.254

All servers are running Server 2008 R2.

My switch is a Cisco 6509 with the following configs:

The switch port configurations are as follows:
interface GigabitEthernet9/24
description SERVERM
switchport
switchport access vlan 200
switchport mode access
switchport nonegotiate
flowcontrol receive on
flowcontrol send on
spanning-tree portfast edge
spanning-tree bpduguard enable

interface GigabitEthernet9/44
description DC13
switchport
switchport access vlan 200
switchport mode access
switchport nonegotiate
flowcontrol receive on
flowcontrol send on
spanning-tree portfast edge
spanning-tree bpduguard enable

When I try to ping from ServerM to DC13, I get the following:

Pinging 192.168.101.17 with 32 bytes of data:
Reply from 192.168.101.103: Destination host unreachable.
Reply from 192.168.101.103: Destination host unreachable.
Reply from 192.168.101.103: Destination host unreachable.
Reply from 192.168.101.103: Destination host unreachable.

The destination host unreachable is telling me that communication is failing at layer 2. To verify this, I did an arp –a and got the following:

C:\Users\eugened>arp -a

Interface: 192.168.101.103 --- 0xb
Internet Address Physical Address Type
192.168.101.100 02-fb-0b-01-45-62 dynamic
192.168.101.101 02-fb-0b-01-45-62 dynamic
192.168.101.102 02-fb-0b-01-45-62 dynamic
192.168.101.104 05-cb-1b-04-22-63 dynamic
192.168.101.106 02-fb-0b-e5-22-80 dynamic
192.168.101.107 02-fb-0b-e5-22-80 dynamic
192.168.101.109 04-cb-0c-e5-99-70 dynamic
192.168.101.254 02-bb-0c-d5-f9-d0 dynamic
192.168.101.255 ff-ff-ff-ff-ff-ff static
224.0.0.22 01-00-5e-00-00-16 static
224.0.0.252 01-00-5e-00-00-fc static

There is no entry in the arp table for 192.168.101.17.

From all other servers on the subnet, I can ping DC13. From all other servers on the subnet, I see an entry for DC13 in their arp table. I can also ping DC13 from the switch and I see an entry for DC13 in the switch’s MAC address table. Finally, I can successfully ping DC13 from my workstation which is on a different subnet.

From DC13, I can ping all servers in the subnet except ServerM. When I ping ServerM from DC13, I get the following:

Pinging server.mydomain.local [192.168.101.103] with 32 bytes of data:
Request timed out.
Request timed out.
Request timed out.
Request timed out.

Since I got a request timed out, this is telling me layer 2 is working. I verified this with an arp –a on DC13 and got the following

C:\Users\eugened>arp -a

Interface: 192.168.101.17 --- 0xa
Internet Address Physical Address Type
192.168.101.100 02-fb-0b-01-45-62 dynamic
192.168.101.101 02-fb-0b-01-45-62 dynamic
192.168.101.102 02-fb-0b-01-45-62 dynamic
192.168.101.103 06-ac-1b-05-66-63 dynamic
192.168.101.104 05-cb-1b-04-22-63 dynamic
192.168.101.106 02-fb-0b-e5-22-80 dynamic
192.168.101.107 02-fb-0b-e5-22-80 dynamic
192.168.101.109 04-cb-0c-e5-99-70 dynamic
192.168.101.254 02-bb-0c-d5-f9-d0 dynamic
192.168.101.255 ff-ff-ff-ff-ff-ff static
224.0.0.22 01-00-5e-00-00-16 static
224.0.0.252 01-00-5e-00-00-fc static

At this point I’m at a loss why ServerM cannot communicate with DC13. I’m hoping a second set of eyes can see something I’m missing. Please feel free to share any thoughts or ideas.

Nick

ZIMSINGY

What can ServerM see/ping?

Jizzai

Can you ping ServerM from the switch and do you see an entry for ServerM in the switch’s MAC address table?

Can ServerM ping itself?

masnrock

Have you tried a tracert from ServerM? Were you trying to ping by IP address, name, or both? Try to do a DNS lookup of DC13 from ServerM and see if it gives a correct result. I'd also see if there are any static routes or rules defined anywhere (Windows Firewall, switch itself...)

ndalmolin_13

ASKER

I can ping ServerM from the switch and I do see it in the switch MAC address table. ServerM can ping itself. There are two ip addresses on the ServerM Nick. The second IP is 192.168.101.105. This ip is also a second IP for ServerL. I asked the exchange guy why this was done and he said load balancing. DNS resolves correctly on ServerM. We are going to try turning the Windows firewall off on Dc16. The firewall is off on ServerM.

Craig Beck

Are you sure the firewall is off on ServerM? Do you have any AV installed that does firewalling?

Also, turn flow-control off at the ports on the switch and the server NICs. It'll just cause problems.

Azhar Mohammad

first ping its self in both server, if its working.
then ping server to DG = 192.168.101.254.
if both test pass then

Both server firewall turn if off and check, it will work.
configuration look ok.

ndalmolin_13

ASKER

We have turned off firewalls on all servers and still no luck.

ASKER CERTIFIED SOLUTION

Jizzai

membership

This solution is only available to members.

To access this solution, you must be a member of Experts Exchange.

Start Free Trial

ndalmolin_13

ASKER

I will try removing the second IP on ServerM and see if that works.

Craig Beck

Can't see how a second IP would cause it.