I have 3 Cisco 3750 switches that are connected via trunk links to each other. When I do:
ping 172.31.6.11
sho arp
on 1 of my switches it doesn't even show the ip and the coresponding mac-address. This particular host is physically plugged into port 10 on that switch.
on the 2nd or 3rd switch switches it shows the mac-address and it's the same mac-address for a lot of different ip addresses, meaning that these ips are located on a different switch. I follow it up the chain and then when I get to the 1st switch and I try to do a "sho mac-address-table", it shows that it's going out of interface 1/0/1 which goes out to another location across town.
Here's my config for that 1st switch where this host is located:
Current configuration : 8085 bytes
!
! Last configuration change at 15:07:48 PDT Tue Oct 9 2007 by admin
! NVRAM config last updated at 15:10:07 PDT Wed Sep 19 2007 by admin
!
version 12.2
no service pad
service timestamps debug datetime localtime
service timestamps log datetime localtime
service password-encryption
!
hostname 1st3750
!
enable password xxx
!
username damiens privilege 15 password xxx
username admin privilege 15 secret xxx
no aaa new-model
clock timezone PST -8
clock summer-time PDT recurring
switch 1 provision ws-c3750g-24ts
vtp domain TEST
vtp mode transparent
ip subnet-zero
ip cef load-sharing algorithm universal CB41AB75
ip domain-name dcipa.com
ip name-server 172.16.x.x
ip name-server 172.16.x.x
!
!
mls qos
!
crypto pki trustpoint TP-self-signed-3281851776
enrollment selfsigned
subject-name cn=IOS-Self-Signed-Certificate-3281851776
revocation-check none
rsakeypair TP-self-signed-3281851776
no file verify auto
spanning-tree mode pvst
no spanning-tree optimize bpdu transmission
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
vlan 99
name voice
!
vlan 100
name IT
!
vlan 120
name TEST
!
vlan 121
name ABC-Servers
!
vlan 300
name management
!
interface GigabitEthernet1/0/1
description to HMP
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface GigabitEthernet1/0/2
switchport access vlan 100
switchport voice vlan 99
spanning-tree portfast
!
interface GigabitEthernet1/0/3
switchport access vlan 100
switchport voice vlan 99
spanning-tree portfast
!
interface GigabitEthernet1/0/4
switchport access vlan 100
switchport voice vlan 99
spanning-tree portfast
!
interface GigabitEthernet1/0/5
switchport access vlan 100
switchport voice vlan 99
spanning-tree portfast
!
etc, etc......
interface GigabitEthernet1/0/22
switchport access vlan 100
switchport voice vlan 99
spanning-tree portfast
!
interface GigabitEthernet1/0/23
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface GigabitEthernet1/0/24
switchport trunk encapsulation dot1q
switchport mode trunk
!
interface GigabitEthernet1/0/25
!
interface GigabitEthernet1/0/26
!
interface Vlan1
no ip address
no ip route-cache
shutdown
!
interface Vlan300
ip address 172.30.x.x 255.255.255.0
no ip route-cache
!
ip default-gateway 172.30.x.x
ip classless
ip http server
no ip http secure-server
!
snmp-server community abct RW
snmp-server community public RO
!
control-plane
