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Destination Host Unreachable but Gateway Pingable

Getting this?

[root@mdskvm-p05 ~]# ping 10.0.0.73
PING 10.0.0.73 (10.0.0.73) 56(84) bytes of data.
From 10.0.0.72 icmp_seq=1 Destination Host Unreachable
From 10.0.0.72 icmp_seq=2 Destination Host Unreachable
From 10.0.0.72 icmp_seq=3 Destination Host Unreachable

Pinging gateway works but doesn't go beyond that?


[root@mdskvm-p05 ~]# ping 10.0.0.1
PING 10.0.0.1 (10.0.0.1) 56(84) bytes of data.
64 bytes from 10.0.0.1: icmp_seq=1 ttl=255 time=1.75 ms
64 bytes from 10.0.0.1: icmp_seq=2 ttl=255 time=0.715 ms


Start by checking on Switch 2 where most of the cables are plugged into.  One of the interfaces is set to VLAN 1 but no GE port is associated with it:

mdscisco02#
mdscisco02#show mac address-table | include 4ea
   1    d89d.6723.4ea5   dynamic ip                    Port-channel4
   2    d89d.6723.4ea4   dynamic ip,other              GigabitEthernet1/12
   2    d89d.6723.4ea6   dynamic ip,other              GigabitEthernet1/13
   2    d89d.6723.4ea7   dynamic ip,other              GigabitEthernet1/15
mdscisco02#
mdscisco02#
mdscisco02#
mdscisco02#show mac address-table | include 827
   2    2c44.fd96.8274   dynamic ip,other              Port-channel4
   2    2c44.fd96.8275   dynamic ip,ipx,other          GigabitEthernet1/14
   2    2c44.fd96.8276   dynamic ip,ipx,other          GigabitEthernet1/11
   2    2c44.fd96.8277   dynamic ip,ipx,other          GigabitEthernet1/16
mdscisco02#
mdscisco02#
mdscisco02#
mdscisco02#show vlan

VLAN Name                             Status    Ports
—- ——————————– ——— ——————————-
1    default                          active    Gi1/2, Gi1/3, Gi1/4, Gi1/5, Gi1/6, Gi1/7, Gi1/8, Gi1/9, Gi1/10, Gi1/17, Gi1/18, Gi1/19
                                                Gi1/20, Gi1/21, Gi1/22, Gi1/23, Gi1/24, Gi1/25, Gi1/26, Gi1/27, Gi1/28, Gi1/29, Gi1/30
                                                Gi1/31, Gi1/32, Gi1/43, Gi1/44, Gi1/45, Gi1/46, Gi1/47, Gi1/48, Te1/49, Te1/50
2    VLAN0002                         active    Gi1/11, Gi1/12, Gi1/13, Gi1/14, Gi1/15, Gi1/16
3    VLAN0003                         active
4    VLAN0004                         active
5    VLAN0005                         active    Gi1/33, Gi1/34, Gi1/35, Gi1/36, Gi1/37, Gi1/38, Gi1/39, Gi1/40, Gi1/41, Gi1/42
1002 fddi-default                     act/unsup
1003 trcrf-default                    act/unsup
1004 fddinet-default                  act/unsup
1005 trbrf-default                    act/unsup

VLAN Type  SAID       MTU   Parent RingNo BridgeNo Stp  BrdgMode Trans1 Trans2
—- —– ———- —– —— —— ——– —- ——– —— ——
1    enet  100001     1500  –      –      –        –    –        0      0
2    enet  100002     1500  –      –      –        –    –        0      0
3    enet  100003     1500  –      –      –        –    –        0      0
4    enet  100004     1500  –      –      –        –    –        0      0
5    enet  100005     1500  –      –      –        –    –        0      0
1002 fddi  101002     1500  –      –      –        –    –        0      0
1003 trcrf 101003     4472  1005   3276   –        –    srb      0      0
1004 fdnet 101004     1500  –      –      –        ieee –        0      0
1005 trbrf 101005     4472  –      –      15       ibm  –        0      0


VLAN AREHops STEHops Backup CRF
—- ——- ——- ———-
1003 7       7       off

Remote SPAN VLANs
——————————————————————————


Primary Secondary Type              Ports
——- ——— —————– ——————————————

mdscisco02#

Verifying the cables shows 1 cable of each host is connected to the Cisco 3750.  Checking on Switch 1 for the connection we see that one of the interfaces is set to VLAN 1:

mdscisco01#show mac address-table | include 827
   2    2c44.fd96.8274    DYNAMIC     Gi1/0/10
   2    2c44.fd96.8275    DYNAMIC     Po4
   2    2c44.fd96.8276    DYNAMIC     Po4
   2    2c44.fd96.8277    DYNAMIC     Po4
mdscisco01#
mdscisco01#
mdscisco01#show mac address-table | include 4ea
   1    d89d.6723.4ea5    DYNAMIC     Gi1/0/7
   2    d89d.6723.4ea4    DYNAMIC     Po4
   2    d89d.6723.4ea6    DYNAMIC     Po4
   2    d89d.6723.4ea7    DYNAMIC     Po4
mdscisco01#


After the change, Gi1/0/7 is set to VLAN 2:

!
interface GigabitEthernet1/0/5                # Needs to be removed.  Cable plugged into 1/0/7 instead.
 switchport access vlan 2
 switchport mode access
!
interface GigabitEthernet1/0/6
!
interface GigabitEthernet1/0/7
 switchport access vlan 2
 switchport mode access

!
interface GigabitEthernet1/0/8
!
interface GigabitEthernet1/0/9
!
interface GigabitEthernet1/0/10
 switchport access vlan 2
 switchport mode access
!
interface GigabitEthernet1/0/11
!
interface GigabitEthernet1/0/12
!

Verify the mac address-table above on both switches:


mdscisco02#show mac address-table | include 4ea
   2    d89d.6723.4ea4   dynamic ip,other              GigabitEthernet1/12
   2    d89d.6723.4ea5   dynamic ip                    Port-channel4
   2    d89d.6723.4ea6   dynamic ip,other              GigabitEthernet1/13
   2    d89d.6723.4ea7   dynamic ip,other              GigabitEthernet1/15
mdscisco02#show mac address-table | include 827
   2    2c44.fd96.8274   dynamic ip,other              Port-channel4
   2    2c44.fd96.8275   dynamic ip,ipx,other          GigabitEthernet1/14
   2    2c44.fd96.8276   dynamic ip,ipx,other          GigabitEthernet1/11
   2    2c44.fd96.8277   dynamic ip,ipx,other          GigabitEthernet1/16
mdscisco02#

mdscisco01#show mac address-table | include 4ea
   2    d89d.6723.4ea4    DYNAMIC     Po4
   2    d89d.6723.4ea5    DYNAMIC     Gi1/0/7
   2    d89d.6723.4ea6    DYNAMIC     Po4
   2    d89d.6723.4ea7    DYNAMIC     Po4
mdscisco01#show mac address-table | include 827
   2    2c44.fd96.8274    DYNAMIC     Gi1/0/10
   2    2c44.fd96.8275    DYNAMIC     Po4
   2    2c44.fd96.8276    DYNAMIC     Po4
   2    2c44.fd96.8277    DYNAMIC     Po4
mdscisco01#


Verify on the OS itself that instead of this:

[root@mdskvm-p05 ~]# ping 10.0.0.73
PING 10.0.0.73 (10.0.0.73) 56(84) bytes of data.
From 10.0.0.72 icmp_seq=1 Destination Host Unreachable

a proper reply is seen instead:

[root@mdskvm-p05 network-scripts]# ping 10.0.0.73
PING 10.0.0.73 (10.0.0.73) 56(84) bytes of data.
64 bytes from 10.0.0.73: icmp_seq=1 ttl=64 time=0.295 ms

Regards,
GM

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