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Different VLAN Interface on 2950

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Eistee

Technical User
Dec 15, 2002
7
CH
I have two 6500 Catalyst switches with MSFCs and two 6500 without MSFC which I am about to introduce into our network, which currently has 7 subnets and has 7 VLANs implemented. The client PCs (Windows 2000 Pro) connect to the network via Cisco 2950 Switches which connect to the 6500s using gigabit fibre. Gigabit Interface's on 6500 and 2950 are as trunk's confugered. Two 6500 Catalyst switches with MSFCs are in VTP server mode and all other switches are in client mode.
I have been attempting to use one Windows 2000 Server, set up as a Domain Controller, running DHCP, DNS and WINS to allocate different address ranges to different VLANs via a Scope.
The DHCP server is to give addresses out to clients on its own VLAN as well as other VLANs. I have configured the default gateways of each DHCP scope with the IP address of the HSRP address of each VLAN configured on the MSFCs and am using the IP helper command in each VLAN on the MSFC to point to the address of the DHCP server.
This does work to some extent - if I confugure all Interface on 2950 Switch to one VLAN it's works, but if I configure port membership on 2950 to more as 1 VLAN the Switch works just in one VLAN and other Interface's are administratively down. "no shutdown"- command does not help.
Any Idea ?
Eistee
 
I have two thoughts,

1. Is the 2950 in the same VTP Domain as the 6500 server?

2. Are both sides of the trunk configured to pass the VLANs you wish to use?
 
1. All switches are in the same VTP Domain
2. Yes, both sides are configured to pass all VLAN's

Thank's a lot
 
3. Are the trunking ports in the same Native Vlan? Normally this is the administrative vlan, which is vlan 1 by default.
 
Yes, all trunks have native vlan - vlan 1,
on MFCS's is HSRP configured
Core_A:
interface Vlan1
ip address 172.16.200.209 255.255.0.0
no ip redirects
mls rp vtp-domain BUZ
mls rp management-interface
mls rp ip
standby 1 priority 50
standby 1 ip 172.16.200.220
!
interface Vlan51
description ****FL_1.Geschoss****
ip address 172.17.51.2 255.255.255.0
ip helper-address 172.16.3.10
no ip redirects
mls rp vtp-domain BUZ
mls rp ip
standby 51 priority 150 preempt
standby 51 ip 172.17.51.1
!
___________________________________________
on CoreB:
interface Vlan1
ip address 172.16.200.209 255.255.0.0
mls rp vtp-domain BUZ
mls rp management-interface
mls rp ip
standby 1 priority 50
standby 1 ip 172.16.200.220
!
interface Vlan51
description ****FL_1.Geschoss****
ip address 172.17.51.3 255.255.255.0
ip helper-address 172.16.3.10
no ip redirects
mls rp vtp-domain BUZ
mls rp ip
standby 51 priority 50
standby 51 ip 172.17.51.1
!
From PC in VLAN1 I can get all Networks and Default Gateway
PC in VLAN51 has Default Gateway HSRP L3 Address: 172.17.51.1, ican ping it too
 
but I can't get all other VLAN's.
I don't have this problem if all ports on 2950 are configured for VLAN51
 
Does this 2950 connect directly to the VTP server? If not is the trunk to the 6500 without the MSFC passing all Vlans on both sides of the trunk?

What is the output of "show vlan" on the 2950? Do you see all of your vlans?


 
Is it on the MSFC that the interface shows as administratively down? I'm not sure I correcty understand your problem.

Also, do you really have the same IP hard-coded on VLAN 1? You should have three addresses per group, like you have VLAN 51.

Regards,

Scott
 
To clarify, do you really have the same IP on both core A and core B for VLAN 1?
 
Yes, I do, should I realy have three Adresses in Managment VLAN too?
 
No, it's not the Interface on the MSFC that shows as administratively down, it's the Interface on 2950
 
I don't do HSRP for VLAN 1 myself. Yes, uou will require that each MSFC have its own unique IP address regardless of what approach you take. I prefer just to have two 0.0.0.0 routes on each switch. The first entry points to Core A MSFC and the second points to Core B MSFC. No HSRP necessary.

There may actually be an advantage to running HSRP. I should think it through carefully. But I think the switch ARPs for the first default gateway and then ARPs for the second if no response is heard. Seems to accomplish the same goal with less complexity. But I'm getting more confident in HSRP these days. Any thoughts guys?

I don't know the 2950 very well. But I do know that VLAN 1 absolutely has to be working perfectly or VTP and a bunch of other stuff breaks. Try getting that going and then we can all go from there.

 
You don't configure actual VLAN interfaces on the access switches.. That interface that is in there, is just the management vlan..

VTP is where it gets all its information from. 'sh vlan' that will tell you whether VTP is working right.


You need to make sure that your VLAN's are enabled on the core switches as well, that could be why traffic isn't passing..


BuckWeet

 
Eistee,
have you checked that the vlans are allowed on the Core Switches(6500)and the access switches(2950).In the configuration of the 2950 under interface VLAN 1 and on the 6500 on the uplink port(allowed vlans).If the vlan data on both uplink ports do not mathch you can not make a connection on any other vlan other than vlan 1.
 
Eistee,
I should have said you will not be able to connect on any vlan that is not defined on both interfaces.
 
Eistee,

How are you defining your vlans on the 2950?
1. Did you define them manually using vlan database, add?
2. Did you let the VTP client download them from the VTP server?
3. Did you use 'interface vlan xxx' to define them?

If you did either 1 or 2 you shouldn't have them shutting down on their own due to a change in management VLAN. IF you did 3, then that is why you are having a problem.

You should get the vlans to the 2950 either manually or via vtp over a trunk. Then assign each port to the vlan you want with 'switchport access vlan xxx'. Hopefully that will correct your problem. Then just make sure the IP helper is installed on the msfc vlan in question.

Todd
 
Please I am having the same problem as the above.

I have a single 2950 connecting to a Core Switch6509. The 6509 is a vtp server and the 2950 is set up as a client. I have a crossover cable between the 2 switches from

Cat2950
Int fa0/1
to
Cat6509
Port 7/4.

The connection comes up ok.

On port 7/4, the following is configured

Port Mode Encapsulation Status Native vlan
-------- ----------- ------------- ------------ -----------
7/4 on dot1q trunking 1

On Cat2950

Port Mode Encapsulation Status Native vlan
Fa0/1 on 802.1q trunking 1

Port Vlans allowed on trunk
Fa0/1 1-4094

So the native vlan on both sides of the line is 1, Speed 100 and duplex full.

The Cat2950 has received all vlan information form the vtp sever Cat6509.

I intend to use the MSFCs on the 6509 to do the routing for devices on the 2950 just like a router on a stick.

I next configured an interface on the 2950 as a switch access to vlan 22.

interface FastEthernet0/23
switchport access vlan 22
switchport mode access
no ip address
duplex full
speed 100
spanning-tree portfast

Vlan 22 has been configured on the MSFcs and this works fine as we have devices on the Cat 6509 which uses it. The Vlan 22 has an ip helper address and my intention is for the devices on the 2950 to also obtain ip addresses from the dhcp server configured thus

interface Vlan22
description Office Network
ip address 10.22.24.251 255.255.255.0
ip helper-address 10.33.33.10
standby 22 ip 10.22.24.254
standby 22 priority 120
standby 22 preempt

But here is where it does not work. When I plug in a device on the 2950, it does not get an ip address, I put in a valid static address in the range and still it will not work.

From the 2950, I can successfully ping the dhcp server and all devices.

So please how do I get devices on the 2950 to use the MSFc as a routing device. In short how do I get this to work.

Thanks
 
Hi vallan,

Would you post a sh running for the 2950?

By the way, why did you not post a new question? I would do that.

 
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