09-30-2011 08:34 AM - edited 03-07-2019 02:32 AM
Hi,
i have two switces at the site one is 4507 and another one is 3560 switch.4507 is configured as a core switch and 3560 switch configured as a access switch and vla 160 is a layer 3 vlan configured on both the switch and which providing connectivity between switches.
The ip address assigned to the core switch is 172.18.160.2 and eigrp is running betwen this switch and remote location.
The IP address assigned to the access switch is 172.18.160.6.
Here comes my question,i didnt configure any default route or any routing protol on the access switch,but still i am able to ping all the locations.How is it possible that the switch is pinging to outside address without any static,default route and routing protocol.
Please reply ASAP.
Thanks
Sathya
09-30-2011 08:42 AM
Hi,
Do you have "ip default-gateway ip-address" configured on your access switch?
09-30-2011 09:38 AM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
Is the gateway interface for 172.18.160.6 supporting proxy ARP?
09-30-2011 11:53 AM
Hi Reza,
i dont have any ip default-gateway address command configured.
Hi Joseph,
How to check that whether the gateway interface is supporting proxy ARP?and what is this proxy ARP.
09-30-2011 12:00 PM
Hi,
Can you post "sh run" from the access switch?
09-30-2011 12:08 PM
Please find the access switch config below.
ASB-BAN-SW55#sh run
Building configuration...
Current configuration : 11459 bytes
!
version 12.2
no service pad
service tcp-keepalives-in
service tcp-keepalives-out
service timestamps debug datetime msec localtime show-timezone
service timestamps log datetime msec localtime show-timezone
service password-encryption
service sequence-numbers
!
hostname ASB-BAN-SW55
!
logging buffered 16384 debugging
logging rate-limit 10 except critical
logging console critical
enable secret 5 $1$Ji3F$cxhrbDQnFzoDlzbSnU4C3.
!
no aaa new-model
vtp domain VELANKANISW1
vtp mode transparent
ip subnet-zero
no ip source-route
no ip gratuitous-arps
ip tcp synwait-time 20
no ip domain-lookup
ip domain-name ascorp.com
ip name-server 172.24.131.37
!
ip ssh authentication-retries 2
ip ssh source-interface Loopback0
ip ssh version 2
!
!
!
!
!
no file verify auto
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
vlan 160
name Server-Printer
!
vlan 164
name Data-VLAN-1stFLR
!
vlan 174
name Voice-VLAN-1stFLR
!
vlan 190
name Guest-New
!
!
interface Loopback0
ip address 172.31.254.116 255.255.255.255
no ip redirects
no ip proxy-arp
!
interface FastEthernet0/1
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/2
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/3
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/4
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/5
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/6
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/7
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/8
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/9
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/10
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/11
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/12
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/13
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/14
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/15
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/16
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/17
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/18
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/19
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/20
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/21
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/22
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/23
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/24
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/25
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/26
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/27
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/28
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/29
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/30
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/31
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/32
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/33
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/34
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/35
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/36
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/37
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/38
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/39
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/40
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/41
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/42
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/43
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/44
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/45
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/46
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/47
switchport access vlan 164
switchport mode access
switchport voice vlan 174
speed 100
duplex full
spanning-tree portfast
!
interface FastEthernet0/48
description #connectivity to ASB-BAN-SW51#PORT NO-GI7/48
switchport trunk encapsulation dot1q
switchport mode trunk
speed 100
duplex full
!
interface GigabitEthernet0/1
shutdown
!
interface GigabitEthernet0/2
shutdown
!
interface GigabitEthernet0/3
shutdown
!
interface GigabitEthernet0/4
shutdown
!
interface Vlan1
no ip address
shutdown
!
interface Vlan160
ip address 172.18.160.6 255.255.255.0
!
ip classless
no ip http server
no ip http secure-server
!
!
logging trap warnings
logging facility local2
logging source-interface Loopback0
logging 172.24.131.45
access-list 23 permit 172.18.44.0 0.0.0.255
access-list 23 permit 172.20.8.0 0.0.0.255
access-list 23 permit 172.31.254.0 0.0.0.255
access-list 24 permit 172.24.131.37
access-list 24 permit 172.24.131.45
access-list 24 permit 10.20.2.55
access-list 50 permit 172.24.128.117
access-list 50 permit 172.18.70.132
access-list 50 permit 172.20.8.14
access-list 50 permit 172.20.8.15
snmp-server trap-source Loopback0
snmp-server contact Network Management
snmp-server chassis-id
snmp-server enable traps snmp authentication linkdown linkup coldstart
snmp-server enable traps cluster
snmp-server enable traps entity
snmp-server enable traps vtp
snmp-server enable traps config
snmp-server enable traps hsrp
snmp-server enable traps bridge newroot topologychange
snmp-server enable traps vlan-membership
snmp-server host 172.24.128.117 OTXREAD
!
control-plane
!
banner motd ^CCCC
************************* WARNING ********************************
* *
* This computer system is private and may be accessed only *
* by authorized users. Data and programs in this system *
* are confidential and proprietary to the system owner and *
* may not be accessed, viewed, copied, reproduced, duplicated, *
* modifed, distributed, or disclosed without authorization. *
* Access to this system is logged and may be used as evidence *
* in court. Unauthorized users will be prosecuted to the full *
* extent of federal and state law,including criminal prosecution *
* which may result in fines,imprisonment or both. *
* *
* If you are not authorized to use this system *
* YOU MUST EXIT IMMEDIATELY! *
* *
******************************************************************
^C
!
line con 0
exec-timeout 5 0
password 7 04750E120226415A584B5653
login
line vty 0 4
session-timeout 10
exec-timeout 5 0
password 7 080F495A041E080343595F40
login
line vty 5 15
no login
!
scheduler interval 500
ntp clock-period 36028847
ntp source Loopback0
ntp access-group peer 24
ntp server 172.24.131.37
ntp server 172.24.131.45
ntp server 10.20.2.55
!
end
09-30-2011 01:38 PM
The 4507 and the 3560 should be able to ping each becuase the are directly connected neighbors. Are you saying you have other sites on different subnets that the 3560 can reach?
Jonathan,
09-30-2011 05:21 PM
Disclaimer
The Author of this posting offers the information contained within this posting without consideration and with the reader's understanding that there's no implied or expressed suitability or fitness for any purpose. Information provided is for informational purposes only and should not be construed as rendering professional advice of any kind. Usage of this posting's information is solely at reader's own risk.
Liability Disclaimer
In no event shall Author be liable for any damages whatsoever (including, without limitation, damages for loss of use, data or profit) arising out of the use or inability to use the posting's information even if Author has been advised of the possibility of such damage.
Posting
sathyasav wrote:
Hi Joseph,How to check that whether the gateway interface is supporting proxy ARP?and what is this proxy ARP.
This will help explain:
http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a0080094adb.shtml
10-04-2011 05:41 AM
So,if we enable proxy ARP on the core,default gateway is not required right to reach the outside world?
10-04-2011 05:51 AM
Yes, but the better solution is to configure a default-gateway on your L2 switches if you want to access them from remote subnets.
You should not rely on proxy-arp to do this. Basically your access switch arps for for every destination and relies on the core switch to work it out. If you configure a default-gateway on the switch then the switch simply needs arp to resolve the default-gateway IP address (+ any devices local to the switch management IP subnet).
Jon
10-04-2011 06:00 AM
Thanks Jon,
So it is always better to configure default gateway rather than depending on proxy ARP rite?
so eventhough we dont configure default gateway with the proxy ARP enabled,we can reach the outside subnets and viceversa.But it is always better to configure default gateway rather than depending on proxy ARP rite?
Jon please reply for this post.
SATHYA
10-04-2011 08:19 AM
Sathya
Yes. Even though it can work using proxy arp, it is always better to configure a default gateway rather than depending on proxy arp.
HTH
Rick
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