8000m and 2524

[JonK]

Is it true the hp 2524 and 8000m do not support two mac addresses with vlan ?

Apparently the people who manage our cisco router cannot change the mac address and we have clients wanting to use the router.

Pings out to the router will work SOMETIMES and other times req time out unless I pull out the other interface from router then it works fine because only one mac address from router.

Thanks
Jon

[Matt Hobbs]

The 2524's and 8000M's have a single mac-address table for all VLANs. This means that the switch is going to get upset if it sees the same mac-address on two different ports.

The solution is mentioned in the FAQ:

http://www.hp.com/rnd/support/faqs/23xx_25xx.htm#question27

You need to use the 1 connection only to the Cisco, using an 802.1Q tagged link.

The people that look after the Cisco should definitely be able set this up.

On your 2524 end, all you will need to do is something like this:
2524(config)# vlan 2
2524(vlan-2)# tagged

VLAN1 the default VLAN will remain untagged or 'native', VLAN2 traffic will be tagged.

Don't forget to assign points.

[JonK]

Thanks
I see what you mean however,
We have two networks at school, admin and curric. The cisco router has two ports one for admin and one for curric.

We also have an admin switch which the admin router port is connected to. All is fine except the 2 admin vlan clients using the curric switch (8000 and 2524)

I dont think they will want to use 1 port and vlan it to the cisco router. Any other ideas? Or maybe I need to setup an isa server and have the curric router into that so therefore the 8000m will not see two mac addresses?

[Matt Hobbs]

Just to understand this better... there are 2 ports on the Cisco switch, one is going to a 2524, the other is going to the 8000M.

There is a link between the 2524 (Curriculum) and the 8000M (Admin) that carries Admin traffic over to the 2524. I might have the Admin/Curriculum wrong but it's not really important.

If this is the case, the best solution would be to remove this link between the 2524 and the 8000M.

For the switch that needs to carry traffic for both VLANs, have the Cisco configured to do so as mentioned above, and make the appropriate changes to the ProCurve switch.

The other switch can remain plugged into the second port on the Cisco unchanged.

This will ensure that the Cisco's mac-address is only seen on the uplink port to the Cisco itself.

The only other solution I can think of would be to replace the 2524 with a 2626.

[JonK]

The router (curric) is in the cisco 2950 which is uplinked to hp 8000m. Hp8000m has a fibre uplink to 2524 hp. This has blue and red vlan. blue curric, red admin.

The router(admin interface) is in a 3com which has one port into the hp 8000m vlan port. The rest of hp 8000m is curric network.

Cant remove the link between 2524 and 8000m as its 250+ metre away connected with fibre.

Is there any way to change the mac address perhaps with the cisco 2950 ? I tried playing with arp tables but no luck. It appears the hp procurve is not compatible with 2 mac addresses in VLAN configuration

If you telnet to hp 8000m you can see port table switching between the admin vlan port using the admin router and switches back to the curric router - both same MAC address.

Only solution left I think is to run a new pair fibre with new switches. :(

Any ideas? THANKs!

[JonK]

visio 2003 doc attached if that helps

[Matt Hobbs]

I think I understand the network design now.

The Cisco 2950 is the new router, it has a connection to a 3com switch (admin), and a connection to the 8000M (curric).

The 3com has a connection to the 8000M which has a second VLAN configured.

The 8000M has a connection to a 2524 via fibre, carrying both VLANs.

If this is not right can you please attach a basic network map. The only other design I can imagine is that the new Cisco is not the 2950 and is actually another router that connects into the 2950 and 3com, either way the concept is the same.

With the 2950, you can't change the mac-address so the solution is to create a dot1q trunk on the Cisco that connects both VLANs through to the 8000M (or the 3com). One of the links going to the 3com or the 8000M must be removed. I'd recommend removing the link from the Cisco to the 3com as we can help you configure the ProCurve side easier if necessary.

If you are concerned about the bandwidth being reduced because this link has been removed, instead you can create an FEC trunk (PAgP) between the Cisco and the 8000M. You could have up to 4x 10/100 ports connected this way.

This problem can definitely be solved without the need for a new fibre run or new switches. As long as the 2524 and 8000M do not see the same mac-address on different ports at the same time, it will work.

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[JonK]

Thanks for your help

The Cisco 2950 is a switch. The curric port from a cisco 2811 router plugs into the 2950. The 2950 is uplink to hp 8000m.

The hp 8000m (curric with admin vlan) has a connection to a 3com switch (admin)

The 8000M has a connection to a 2524 via fibre, carrying both VLANs. yes

I cant create a dot1q trunk from the cisco router 2811 because it is not managed by me but by an upstream provider who will not change their "standard" setup.

As long as the 2524 and 8000M do not see the same mac-address on different ports at the same time, it will work. this is correct but not sure what else I can do.

[Matt Hobbs · Accepted solution]

A change definitely needs to be done on the 2811 for this workaround to work, either the dot1q solution, or if possible change the mac-addresses on those interfaces. I'm no Cisco expert but on a lot of their products this is possible.

[Matt Hobbs]

I checked with a few colleagues, they believe it is possible to change the mac-address on those routers:

Router(config)#int gi0/0
Router(config-if)#mac
Router(config-if)#mac-address ?
H.H.H MAC address.