address not accessible

[william.briere]

Hello,

I have a 4507r and have added a new interface vlan 75 with an ip address of 10.75.0.1. I have created an ospf route for the 10.75.0.0 network in the 0 area but for some reason I cannot ping it.

Here is the config in question...

interface Vlan75

ip address 10.75.0.1 255.255.0.0

no ip redirects

!

router ospf 2

log-adjacency-changes

redistribute static metric 200 subnets

network 10.50.0.0 0.0.255.255 area 0

network 10.75.0.0 0.0.255.255 area 0

When I do a show ip route 10.50.0.0 I get..

Routing entry for 10.50.0.0/16

Known via "connected", distance 0, metric 0 (connected, via interface)

Routing Descriptor Blocks:

* directly connected, via Vlan23

Route metric is 0, traffic share count is 1

but for 10.75.0.0 I get

% Subnet not in table

Any ideas?

[mohammedmahmoud]

William,

Your main problem is that your channel group configuration is inconsistent, you need the configuration to be as follows on BOTH switches, second in order for different vlans to intercommunicate between both switches your channel group should be a trunk not an access port:

interface Port-channel2

no ip address

switchport

switchport mode trunk

interface GigabitEthernetx/y1

no ip address

switchport

switchport mode trunk

channel-group 2 mode on

interface GigabitEthernetx/y2

no ip address

switchport

switchport mode trunk

channel-group 2 mode on

interface vlan 75

ip address n.n.n.n m.m.m.m

HTH,

Mohammed Mahmoud.

[william.briere]

Setting the interfaces to trunk is not allowed... See below...

VMWARE-SW1(config-if)#switchport mode trunk

Command rejected: An interface whose trunk encapsulation is "Auto" can not be co

nfigured to "trunk" mode.

[mohammedmahmoud]

William,

No you must do the following first:

VMWARE-SW1(config-if)#switchport trunk encapsulation dot1q

HTH,

Mohammed Mahmoud.

[william.briere]

The config is now done as you describe... I can ping 10.75.0.1 but not 10.75.0.2, the ip address of vlan on the 4948.

[william.briere]

Here are the configs as they are now. I have added only the parts that have changed...

On 4507

interface Port-channel2

switchport

switchport access vlan 75

switchport trunk encapsulation dot1q

switchport mode trunk

interface GigabitEthernet3/31

description Grouped with port37 To VMWARE In Lab

switchport access vlan 75

switchport trunk encapsulation dot1q

switchport mode trunk

speed 1000

duplex full

channel-group 2 mode on

interface GigabitEthernet3/37

description Grouped with port31 To VMWARE In Lab

switchport access vlan 75

switchport trunk encapsulation dot1q

switchport mode trunk

speed 1000

duplex full

channel-group 2 mode on

interface Vlan75

ip address 10.75.0.1 255.255.0.0

no ip redirects

On 4948

interface Port-channel1

description To CORE ROUTER

switchport

switchport trunk encapsulation dot1q

switchport mode trunk

interface GigabitEthernet1/1

switchport trunk encapsulation dot1q

switchport mode trunk

speed 1000

duplex full

channel-group 1 mode on

interface GigabitEthernet1/2

switchport trunk encapsulation dot1q

switchport mode trunk

speed 1000

duplex full

channel-group 1 mode on

interface Vlan75

description VMWARE PRIVATE

ip address 10.75.0.2 255.255.0.0

[mohammedmahmoud]

Hi,

Please attach the final configuration, show ip int brief for both switches and show interfaces trunk.

HTH,

Mohammed Mahmoud.

[william.briere]

Here you go...

[william.briere]

Wow.. a second page...

The Vlan 75 is down as you can see... Not sure why?

[mohammedmahmoud · Accepted solution]

William,

The problem is on the 4948 (vlan 75 is down), please do the following, and please make sure that vlan 75 is present on the 4948:

no ip default-gateway 10.75.0.1

ip route 0.0.0.0 0.0.0.0 10.75.0.1

ip routing

HTH,

Mohammed Mahmoud.

[william.briere]

It works now...

Why can I not use the default-gateway command to get things to go back to the router?

[mohammedmahmoud]

Hi William,

I am really glade that it works now :)

default-gateway is effective only when the switch is working as a layer 2 switch, but just when enabling ip routing on the switch, the default-gateway command is of no use, and thus you must replace it with a default route.

Thank you for using the rating system.

Goodnight, or may be have a nice day according to your time zone.

HTH,

Mohammed Mahmoud.

[william.briere]

That is weird because it seemed as though we were unable to get it working unless going to layer 3... We should have been able to accomplish the tasks done on the 4948 by staying at layer 2 and connecting to a layer 3 device (4507)

Is this not correct?

[manmeetmarwah]

Hi William,

I feel that you would have able to achieve the results while working on layer 2 for 4948 switch, but in that case why you would have chosen to put a default-gateway even i.e. If your 4948 switch is being used as layer 2 switch only, then probably all the clients or end users ( Iam not aware about your topology) would have a gateway for 4507 switch only. And in case you have users/end devices pointing to 4948 switch as gateway then that itself means that you are using it as layer 3 switch.

Manmeet

[william.briere]

I had already put the default gateway on the layer 2 switch, as the 4507 was an acceptable default gateway, but for some reason it didn't work. Any suggestions for me to be able to host multiple vlans on a layer 2 switch where there is a channel-group of ports going back to the layer three device?

[mohammedmahmoud]

Hi William,

Sure you can make it work in layer 2 (i only thought that you were trying to make it work in layer 3), just do the following:

no ip routing

no ip route 0.0.0.0 0.0.0.0 10.75.0.1

ip default-gateway 10.75.0.1

and all the PCs connected to the 4948 and members in VLAN 75 must use the 10.75.0.1 as their gateway.

HTH,

Mohammed Mahmoud.