05-30-2008 07:57 AM - edited 03-05-2019 11:19 PM
I am trying to set up a loopback0 port on my 3550-24. I want to use it as my management port. It lets me configure the loop back.
interface Loopback0
ip address 10.244.244.24 255.255.255.255
ip broadcast-address 10.244.244.255
But I can never ping it from my work station. I can't figure out what I am doing wrong. Can anyone help me please?
Thanks
Michael M. Williams
Network Systems Analyst
Information Technology Services
Tarleton State University
Solved! Go to Solution.
05-30-2008 10:18 AM
Mike
There are at least 2 issues here. First and most important you need to enter the command ip routing to enable ip routing. Currently your switch is operating as a layer 2 only switch. You need to enable layer 3 processing to forward packets between VLANs and subnets. Without ip routing enabled it certainly will not do what you want it to do.
Second issue is the attempt to configure the static route. Here is what you entered:
ip route 0.0.0.0 10.244.244.24 255.255.255.255
it appears to contain the destination address, the next hop address, and the mask. But the mask needs to go immediately after the destination address. And the mask is inverted. so it should be:
ip route 0.0.0.0 0.0.0.0 10.244.244.24
Also as a layer 3 switch I am not convinced that the switch uses the loopback interface in the same way that IOS routers do. So even after you address these two problems there may still be some issues
HTH
Rick
05-30-2008 08:01 AM
Hi Michael,
Could you please let us see the config of the switch. Also, if I'm not wrong, you may try enabling Routing on the switch by "ip routing" and see if that helps.
HTH,
Kind Regards,
Wilson Samuel
05-30-2008 08:08 AM
Wilson,
here is my config.
version 12.2
no service pad
service timestamps debug uptime
service timestamps log datetime
service password-encryption
!
hostname network-office
!
enable secret xxxxx
!
no aaa new-model
clock timezone CST -6
clock summer-time CDT recurring
ip subnet-zero
!
!
!
!
!
!
spanning-tree mode pvst
spanning-tree extend system-id
!
vlan internal allocation policy ascending
!
no ip rcmd domain-lookup
ip rcmd rcp-enable
ip rcmd remote-host cwuser 165.95.23.140 cwuser
!
!
!
!
!
interface Loopback0
ip address 10.244.244.24 255.255.255.255
ip broadcast-address 10.244.244.255
!
interface FastEthernet0/1
switchport trunk encapsulation dot1q
switchport trunk native vlan 9
switchport mode trunk
duplex full
spanning-tree portfast
!
interface FastEthernet0/2
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/3
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/4
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/5
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/6
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/7
switchport access vlan 104
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/8
switchport access vlan 9
switchport mode dynamic desirable
spanning-tree portfast
!
interface FastEthernet0/9
switchport access vlan 3
switchport mode dynamic desirable
spanning-tree portfast
!
interface Vlan1
no ip address
!
interface Vlan9
ip address xxx.xx.21.113 255.255.255.128
!
ip default-gateway xxx.xx.21.125
ip classless
ip http server
ip http secure-server
!
!
logging trap critical
logging xxx.xx.23.140
snmp-server community TSUroCN RO
snmp-server community TSUrwCN RW
snmp-server contact
snmp-server system-shutdown
snmp-server enable traps snmp authentication lin
snmp-server enable traps cluster
snmp-server enable traps entity
snmp-server enable traps envmon fan shutdown sup
snmp-server enable traps vtp
snmp-server enable traps vlancreate
snmp-server enable traps vlandelete
snmp-server enable traps flash insertion removal
snmp-server enable traps port-security
snmp-server enable traps config-copy
snmp-server enable traps config
snmp-server enable traps hsrp
snmp-server enable traps bridge newroot topology
snmp-server enable traps stpx inconsistency root
y
snmp-server enable traps syslog
snmp-server enable traps rtr
snmp-server enable traps mac-notification
snmp-server enable traps vlan-membership
snmp-server host xxx.xx.23.140 TSUroCN
!
control-plane
!
!
line con 0
line vty 0 4
password xxxxxxxx
login
line vty 5 15
login
!
ntp clock-period 17180256
ntp server 10.1.1.1 key 0 prefer
end
network-office#
i get this error when i try to enter a route.
network-office#config t
Enter configuration commands, one per line. End with CNTL/Z.
network-office(config)#interface loopback0
network-office(config-if)#ip route 0.0.0.0 10.244.244.24 255.255.255.255
%Inconsistent address and mask
network-office(config)#
Thanks
mike
05-30-2008 08:21 AM
Hi
In which vlan is u r system connected.can u verify plz.
Thanks
Mahmood
05-30-2008 08:38 AM
Mahmood,
The switch IP that I have now and workstation are in the same VLAN. The IP I want to use for LooPback0 is not within any VLAN. I have a 6500 series that is using the same loopback0 IP range and I have no problem pining it. But when I try the 3550 I can't get it to work.
Thanks
Mike
05-30-2008 08:53 AM
HI
R u locally connected to this switch..?
If u then u need to use the default-gateway on ur system as the ip address of the SVI i.e vlan 9 as per u r config.
If u r not locally connected then u need either advertise u r loopback ip in any routing protocol or u need to have static routes for this network.
Thanks
Mahmood
05-30-2008 09:03 AM
Mahmood,
I am connected locally. How would I advertise my loopback. Where would I put the static route?
thanks
Mike
05-30-2008 09:18 AM
Hi Mike,
Please do "sh ip int brief" and "sh ip route" commands. To make sure that you add "ip routing" command in the switch. Because you are trying to let switch routes the networks!
let us know how things work out
Thot
05-30-2008 10:05 AM
Thot,
sh ip int brief
FastEthernet0/4 unassigned YES unset down down
FastEthernet0/5 unassigned YES unset down down
FastEthernet0/6 unassigned YES unset up up
FastEthernet0/7 unassigned YES unset down down
FastEthernet0/8 unassigned YES unset up up
FastEthernet0/9 unassigned YES unset up up
FastEthernet0/10 unassigned YES unset down down
FastEthernet0/11 unassigned YES unset down down
FastEthernet0/12 unassigned YES unset down down
FastEthernet0/13 unassigned YES unset down down
FastEthernet0/14 unassigned YES unset down down
FastEthernet0/15 unassigned YES unset down down
FastEthernet0/16 unassigned YES unset down down
FastEthernet0/17 unassigned YES unset down down
FastEthernet0/18 unassigned YES unset down down
FastEthernet0/19 unassigned YES unset down down
FastEthernet0/20 unassigned YES unset down down
FastEthernet0/21 unassigned YES unset down down
FastEthernet0/22 unassigned YES unset down down
FastEthernet0/23 unassigned YES unset up up
FastEthernet0/24 unassigned YES unset up up
GigabitEthernet0/1 unassigned YES unset down down
GigabitEthernet0/2 unassigned YES unset down down
Loopback0 10.244.244.24 YES manual up up
show ip route
network-office#show ip route
Default gateway is xxx.xx.21.125
Host Gateway Last Use Total Uses Interface
ICMP redirect cache is empty
network-office#
it only show the DF for VLAn 9, which is what the trunk port is config for.
thanks
mike
05-30-2008 10:08 AM
Hi
U need to enable ip routing
config t
ip routing
Thanks
Mahmood
05-30-2008 10:14 AM
Mahmood,
I enable ip routing.
Gateway of last resort is not set
10.0.0.0/32 is subnetted, 1 subnets
C 10.244.244.24 is directly connected, Loopback0
xxx.xx.0.0/25 is subnetted, 1 subnets
C xxx.xx.21.0 is directly connected, Vlan9
network-office#
Still can't ping it.
Thanks
mike
05-30-2008 10:02 AM
Hi
Whats the gateway on u r system,is it the ip address of svi ie. vlan9 of ur switch if so then u need to enable ip routing on u r switch n try.
Thanks
Mahmood
05-30-2008 10:10 AM
Mahmood,
network-office#show ip route
Default gateway is xxx.xx.21.125
Host Gateway Last Use Total Uses Interface
ICMP redirect cache is empty
network-office#
It is the gateway for VLAn 9.
What do I need to do to add gateway for Loopback0?
Thanks
mike
05-30-2008 10:13 AM
Hi
As informed earlier u need to enable ip routing.
u need not add gateway for loopback as it will be listed as directly connected on u r switch.
Just verify that u have the proper gateway config on u r system i.e PC.
Thanks
Mahmood
05-30-2008 10:18 AM
Mike
There are at least 2 issues here. First and most important you need to enter the command ip routing to enable ip routing. Currently your switch is operating as a layer 2 only switch. You need to enable layer 3 processing to forward packets between VLANs and subnets. Without ip routing enabled it certainly will not do what you want it to do.
Second issue is the attempt to configure the static route. Here is what you entered:
ip route 0.0.0.0 10.244.244.24 255.255.255.255
it appears to contain the destination address, the next hop address, and the mask. But the mask needs to go immediately after the destination address. And the mask is inverted. so it should be:
ip route 0.0.0.0 0.0.0.0 10.244.244.24
Also as a layer 3 switch I am not convinced that the switch uses the loopback interface in the same way that IOS routers do. So even after you address these two problems there may still be some issues
HTH
Rick
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