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New Member

Can't ping vlans from Cisco 4500 as vtp client

I have a Cisco 3560x as a vtp server and the 4500 and 2960s as vtp clients.  All the vlans have been propagated.  For some reason, I'm unable to ping certain vlans from the 4500.  All the 2960s are coming off the 4500.  The 2960s are able to ping vlans with the exception of 1 vlan which is 10.100.1.x. The 10.100.1.x switch is coming off the 3560x via virtual interface vlan 100 (10.100.1.1/24).  From the 3560x, I have no problem pinging all the 10.100.1.x devices.  However, from the 4500 and 2960s I'm unable to.  Is there something in the 4500 that I need to config for this to work?  Let me know if you need more info.

Thanks

53 REPLIES
VIP Super Bronze

Re: Can't ping vlans from Cisco 4500 as vtp client

On the 4500 and 2960s do you have Managment IPs? if not create a mgmt ip on each device than try pinging from them

HTH
Sent from Cisco Technical Support iPhone App

New Member

Can't ping vlans from Cisco 4500 as vtp client

Yes, I am able to ping each of the vlan 1 management IPs for Cisco 4500 and 2960s.  The management IPs for them are in same subnet.  I just can't ping the 10.100.1.x network from these devices.  However, from the 3560x (management ip same as 4500 and 2960s) I can ping the 10.100.1.x devices.

VIP Super Bronze

Re: Can't ping vlans from Cisco 4500 as vtp client

What device is doing the routing between vlans?

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New Member

Can't ping vlans from Cisco 4500 as vtp client

The 3560x is doing the routing and acting as the vtp server.

VIP Super Bronze

Re: Can't ping vlans from Cisco 4500 as vtp client

So physically the 4500 and 2960s connect to 3560x right? Are the 4500 and 2960s configured as trunks? Also can you turn on IP routing on the 3560 x and test again
HTH

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New Member

Can't ping vlans from Cisco 4500 as vtp client

The 2960s are connected directly to the 4500 and the 4500 is connected to the 3560x.  The 10.100.1.x switch (3Com) is connected to the 3560x on vlan 100 (10.100.1.1) which is not trunk.  The connections from the 2960s and 4500 are trunk and from the 4500 to the 3560x is trunked.

I tried to trunk the connection from the 10.100.1.2 /24 switch to the 3560x but that cause me not to be able to ping the other 10.100.1.x switches that are connected to the 10.100.1.2.

New Member

Re: Can't ping vlans from Cisco 4500 as vtp client

Would you be able to post the configs of the switches?

New Member

Can't ping vlans from Cisco 4500 as vtp client

Attached is a sample layout of the network. 

Issue #1:  From the 4500, I can ping all the PCs set to vlan1.  However, I can not ping any ip phones set on vlan16 or devices set on vlan 10.  I can ping the virtual interface of vlan16 (10.40.16.1/22) and vlan 10 (10.40.10.1/22).  From the 2960s attached to the 4500, I can ping all the PCs and IP Phones and vlan 10 with no problem.  The 4500 can only ping the PCs that is attached to it and all the vlans virtual interface.

Issue #2: All the 2960s and the 4500 are not able to ping the vlan100 (10.100.1.x).  The only thing that it can ping is its virtual interface of vlan100 (10.100.1.1/24).

The 3560x has no problem pinging any of the devices and pcs.

New Member

Can't ping vlans from Cisco 4500 as vtp client

If you do tracreoutes for these - do they die in a similar place?

New Member

Can't ping vlans from Cisco 4500 as vtp client

From the 4500, doing the traceroute to vlan100 and to the IP Phone or vlan10 will not go anywhere.  From the 2960s, the traceroute to vlan100 will go to 10.40.1.2 and nothing after that, but no problems to the other vlans.

New Member

Can't ping vlans from Cisco 4500 as vtp client

Does your 4500 have an ip default-gateway set?

What does your routing table look like for the vlan100 network?

New Member

Can't ping vlans from Cisco 4500 as vtp client

Yes, the default route is set to 10.40.1.2 /22

Cisco Employee

Can't ping vlans from Cisco 4500 as vtp client

Hello Dan,

By any chane did we  verify whether  the  SVI mac address for the vlan 10 , 100 in 3560 is getting reflected in 4500 and 2960.  I believe this schould be learned over the trunk port. and will be visible under the respective vlan mac address table. If not, try to create static mac entry and verify.

Regards

Partha

New Member

Can't ping vlans from Cisco 4500 as vtp client

Correction, I am unable to ping from the 4500 to any virtual interfaces such as vlan16, vlan10, vlan100.  I tried adding ip route 10.100.1.0 255.255.255.0 10.40.1.2 but that did not work.  I can see all the vlans in 4500 since its set as vtp client.  The 2960s have no problem pinging all the virtual interface of the vlans.

New Member

Can't ping vlans from Cisco 4500 as vtp client

The PCs connected to the 4500 are able to ping all the virtual interface of the vlans (10,16,100).  It can also ping devices in vlan 16, 10.  The only exception is devices in vlan100.

New Member

Can't ping vlans from Cisco 4500 as vtp client

I just don't understand why I can't even ping the virtual interface of vlans 10,16,100 if it's all propapated to the 4500 from 3560x while the 2960s are able to.  All the PCs are able to ping it vlans.

ip default-gateway is 10.40.1.2 /22

no ip routing enable

New Member

Can't ping vlans from Cisco 4500 as vtp client

Can you post the port configurations for the links interconnecting the switches?

New Member

Can't ping vlans from Cisco 4500 as vtp client

From the 4500 --> 3560x   switchport trunk encapsulation dot1q

                                       switchport mode trunk

                     --> 2960s   switchport mode trunk encapsulation dot1q

                                      switchport mode trunk

From the 3560x --> 4500  switchport mode trunk encapsulation dot1q

                                      switchport mode trunk

From all 2060s --> 4500   switchport mode trunk

New Member

Can't ping vlans from Cisco 4500 as vtp client

Cisco 3560x has ip routing enable with ospf.  Do I need to have ip routing enable with ospf in the 4500?  Right now, the 3560x is the vtp server and the 4500 is the vtp client.

New Member

Can't ping vlans from Cisco 4500 as vtp client

If all of the SVIs reside on the 3560x - then you dont need routing enabled on the 4500.

Cisco Employee

Can't ping vlans from Cisco 4500 as vtp client

Dan,

1. Are we getting any arp entry for SVI ips in 4500  ?

2. If step 1 show incomplete. Do we have any native vlan configured in trunk port to 3560 ? if not try configuring the managment vlan as native and verify

Regards

New Member

Can't ping vlans from Cisco 4500 as vtp client

The only arp entry is from vlan1.  How do I go about configuring a native vlan in trunk port to 3560?  Would it disrupt the network?

Cisco Employee

Can't ping vlans from Cisco 4500 as vtp client

Dan,

Can we try this command from 4500 global config mode and verify the status ?

no vlan dot1q tag native

regards

Partha

New Member

Can't ping vlans from Cisco 4500 as vtp client

Will this cause connection issue with the other switches?  We are in production and I don't want to make any changes that might cause a disruption in the network.

New Member

Can't ping vlans from Cisco 4500 as vtp client

Here's what I got from the 4500.  I have not enter the above command.

sh vlan dot1q tag native

dot1q native vlan tagging is disabled globally

--so native vlan tagging state is disabled on all interfaces.

Cisco Employee

Can't ping vlans from Cisco 4500 as vtp client

Dan,

i believe we are able to reach the SVI from 2960

1. Initiate ping from 4500 and 2960 to SVI, then compare the arp table of 2960 with 4500 to find out what are the difference in enteries in arp table?

2.  Do a below manual configuration of native vlan on the trunk port of 4500 (although this is enable by default for vlan 1) and try to verify.

  switchport  trunk native vlan 1

3. If step 2 fails , First clear arp table and then  intiate debug arp in both 4500 and 3560  to verify arp request /response status between 4500 and 3560 when we try to reach the SVI of 3560. This will give fair idea where we are getting stuck.

you can perform these step in off busines hours although execution of these command. will not have any down time.

Regards

Partha

Re: Can't ping vlans from Cisco 4500 as vtp client

Hello

Can you make sure on all switches apart from the 3560 that
1) ip routing is DISABLED
2) vlans are actually propagated in vtp database of all switches and all vlans are allowed to cross the trunks interconnects of these switches

Sh vtp status
Sh vlan brief
Sh int trunk
Sh ip routing (if applicable)

Res
Paul


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New Member

Re: Can't ping vlans from Cisco 4500 as vtp client

All the vlans from the 3560x have propagated to the 4500 and 2960s. 

3560x- vtp server

4500 - vtp client

2960s - vtp client

no ip routing enable on 4500 and 2960s.  Default gateway is pointed to vlan 1 of 3560x.

When telneting into vlan1 of 4500, I cannot ping any SVIs other than vlan1.  The 2960s has no problem.

Is there any other config that needs to be set on vlan 1 of the 4500 since its also a Layer 3 device?  The ports are trunk with the 3560x.

New Member

Re: Can't ping vlans from Cisco 4500 as vtp client

This is what I get when doing a sh ip route from the 4500.

C 10.40.0.0/22 is directly connected, Vlan 1

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