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New Member

Unable to ping a newly created VLAN interface in dual-core 6509

Background

- My company is running dual-core 6509 with dual uplinks for each UA switch.

- All uplinks are running in trunk mode.

- Two core 6509 are connected via a separated VLAN for L3 routing information tramission.

- Two core 6509 are running an single OSPF domain with one and only one active interface for routing update in a dedicated VLAN (the fiber connecting 2 core 6509)

- default static routes are used for WAN service provider

- A large aggregate route in WAN router is used for return route to two core 6509 in order to minimze the number of route for each small VLAN

Problem

1. Whenever I create a new VLAN in two 6509, I couldn't able to ping these interfaces. All ping packet seems to route out. I have tried to "clear ip route *" and "clear ip ospf", but it seems that I still can't reach newly VLAN interface from lower-layer UA switch. The subnet for newly VLAN is a part of summary address from WAN router.

2. It is normal for all other old VLANs.

5 REPLIES

Re: Unable to ping a newly created VLAN interface in dual-core 6

Looks like you did not add the new VLAN to the vtpdatabase.

In that case the status of the vlan interface remains down and it (obviously) does not work.

Do the following in enable-mode:

vlan database

vlan xx name new-vlan

exit

I suppose your C6509 are vtp servers. In that case you have to configure the vlan on on switch only, and it will propagate through the domain automatically.

Regards,

Leo

New Member

Re: Unable to ping a newly created VLAN interface in dual-core 6

Hi Leo,

The case is that I am using CatOS on supervisor engine while IOS for MSFC router. I did create VLAN under CatOS by using "set vlan" command and create VLAN interface under IOS by using "int vlan 257" and "no shut'

I can view the following result under CatOS

HKE6509S8F1> (enable) sh vlan

VLAN Name Status IfIndex Mod/Ports, Vlans

---- -------------------------------- --------- ------- ------------------------

1 default active 5 1/2

3/13-16

4/4-16

9/37-46

......

257 border-router-vlan-b active 188 9/3-4

.....

-------------------------------------------------------------------------------------------------------

While the IOS result by using "sh ip int bri",

HKED6509R8F1#sh ip int bri

Interface IP-Address OK? Method Status Protocol

Vlan2 9.181.192.34 YES NVRAM up up

.............

Vlan256 9.181.192.3 YES NVRAM up up

Vlan257 9.181.192.249 YES manual up up

-------------------------------------------------------------------------------------------------------

Is it related to the Method?? For newly created VLAN, it usualy said "manual" while the old one is always "NVRAM".

Your kind help is highly appreciated

Re: Unable to ping a newly created VLAN interface in dual-core 6

Please check the vtp-status on the MSFC and the CAT: sh vtp stat.

Look at the config revision. This number must be equal on all switches in the domain. The amount of vlans on both should then also be the same. If not, your vtp domain is not synchronized over all devices. One box then knows a vlan while the others do not. This might be the case here.

To sync the vtp domain all settings, exept the operating mode must be equal. You should have at least one vtp-server.

>sh vtp stat

VTP Version : 2

Configuration Revision : 27

Maximum VLANs supported locally : 1005

Number of existing VLANs : 14

VTP Operating Mode : Server

VTP Domain Name : domain

VTP Pruning Mode : Enabled

VTP V2 Mode : Enabled

VTP Traps Generation : Enabled

MD5 digest : 0xE9 0x0C 0x63 0xE9 0x31 0x4D 0x9F 0xB1

Configuration last modified ....

Leo

New Member

Re: Unable to ping a newly created VLAN interface in dual-core 6

Hi Leo,

I have checked that all switches VTP conf revision are the same. The most strange thing is that the VLAN interfaces of both 6509 MSFC can be pingable to each other after several hours of creation of VLAN on MSFC. My usual practice is to create VLAN in supervisor engine first ("set vlan 123") on either 6509 sup. because both are vtp servers. When I used "sh vlan", i am sure that the VLAN on supervisor are created succesfully.

Everytime I create newly VLAN interfaces on MSFC on both 6509, they can't ping each other. Now, I suspected that the implicit virtual trunk config between MSFC and supervisor engine (ie Slot 15/1). Do you know how to force the newly created VLAN on MSFC to propagate out along trunk "15/1"?? What command can I use?? Remember that both VLAN interfaces are pingable to each other after several hours of creation in MSFC.

BTW, I couldn't find "sh vtp stat" command in IOS 12.1 of MSFC and I can only find "sh vtp domain" in CatOS of supervisor engine.

Thank you for your kind help.

Calvin

Re: Unable to ping a newly created VLAN interface in dual-core 6

You may also want to check output of 'show trunk' to make sure the new VLAN is being forwarded across the trunk ports and on 15/1. The 3rd section of the show trunk command is whats active.

Also, show spantree vlan# to make sure STP state is forwarding...

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