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802.1Q Trunk (w/VLANs) Between 2650 and Cisco Router

Frank Mirecki
Occasional Visitor

802.1Q Trunk (w/VLANs) Between 2650 and Cisco Router

Hello All,
I am trying to verify a HP to Cisco configuration. From what I have read I will need to do the following:
Port 1 is connected to Cisco router, ports 2-40 are connected to 802.1Q compliant devices with built in hub, so 802.1Q device is assigned VLAN99 and PC connected to hub on the device is not tagged and therefore is assigned the default vlan 1.
On the HP 2650:
VLAN 99
Name VOIP
tagged 1-40
VLAN 1
tagged 1
untagged 2-40

Cisco:
FastEthernet0/0.1
encapsulation dot1Q 1
ip address 10.1.1.1 255.255.255.0

FastEthernet0/0.99
encapsulation dot1Q 99
ip address 10.1.2.1 255.255.255.0

FastEthernet0/0.1000
description Not_USED
encapsulation dot1Q 1000 native

Do I have to assign an IP address to every VLAN on the HP 2650? Or can I just have the default VLAN have an IP?
2 REPLIES
Jerome Henry
Honored Contributor

Re: 802.1Q Trunk (w/VLANs) Between 2650 and Cisco Router

Basically, providing an IP per port is a good idea to help configuring... even on the same VLAN, it helps you figuring out which port gets where, and so on. But nothing is 'due'...
HTH
J
You can lean only on what resists you...
Arnaud_9
Valued Contributor

Re: 802.1Q Trunk (w/VLANs) Between 2650 and Cisco Router

Hello Franck,

Your configuration seems to be good, but be carreful to the 802.1q compliance of the Cisco Router and the IOS (I think about 3640 which need 128Mb of RAM to run a 802.1q compliant IOS).

There is maybe another way to do the same thing, with VLAN 1 untagged on all port :
This will allow, if needed one day to use a non 802.1q switch to maintain the
VLAN 1 traffic between the Cisco router and clients.
The config should look like this : on the HP 2650:
VLAN 99
Name VOIP
tagged 1-40
VLAN 1
untagged 1-40

Cisco:
FastEthernet0/0.1
encapsulation dot1Q 1
native
ip address 10.1.1.1 255.255.255.0
FastEthernet0/0.99
encapsulation dot1Q 99
ip address 10.1.2.1 255.255.255.0


Has Jerome said, in your case, there is no need for any IP address on the 2650. Assigning an IP address to all VLAN in the 2650 will help troubleshooting if something doesn't work
(ping router and terminal devices in each VLAN).
But if all is working fine, I recommand for more security to restrict IP address to only one VLAN for management.

Devices on VLAN99 look like IP phones, so be careful to QoS on the Cisco Router and also on peer router(s) if voice packets use WAN Links : Look at the Phone manufacturer recommandations about WAN QoS configuration (there are many way to configure it : dscp, udp port, ...), and check
the 802.1p level tagged by the phone for VLAN99 frames. It must be at least level 4 if you want packets placed in the high priority queue in the HP2650.

Arnaud