ProCurve 9304 trunked to Cisco switch

[Ulrik Ivers]

I have a 9304 routing-switch that I want to connect to a Cisco switch (2950G) through a trunk consisting of two FastEtherbet ports.

Anybody know how to configure this the best way? Can't find any documentation on interoperability between the "trunk switch" command in the 9304 and Cisco's Fast EtherChannel (FEC).

All expereinces or comment appreciated.

Regards,
/Ulrik Ivers

[OLARU Dan · Accepted solution]

1. Cisco trunk concept differs from HP trunk concept. For Cisco, a 'trunk' is a method to carry multiple VLANs between switches; a trunk might be defined on just 1 physical cable, or on top of an aggregated channel. For HP a 'trunk' is a method of combining (aggregating) 2, 3 or 4 cables into a fatter pipe for transporting data.

2. FEC is a means for aggregating 2, 3 or 4 individual cables between 2 switches. FEC is Cisco proprietary and is also known as PAgP. HP switches understand FEC, so you can set 2 ports in the 9304 in a 'trunk' of type 'FEC'. Equivalent standards-based term for aggregating links is LACP (Link Aggregation Control Protocol).

3. If you have to carry multiple VLANs across these 2 switches, use IEEE 802.1Q frame tagging method on both switches, since HP 9304 does not understand Cisco's proprietary ISL (Inter-Switch Link) protocol for frame tagging.

4. Aggregating cables to form a fatter data pipe is one thing. Carying VLANs between switches (using aggregated links, or just one cable) is another thing.

5. ON HP:

5.1 Link aggregation

It is easy to define Trk1 as type FEC for ports you want (e.g c2 and d4). I have 4108GL not 9304, but the CLI command should be as follows:
'sw-hp(config)# trunk c2,d4 trk1 fec'

trk1 is just a name with local significance on the HP you're defining it.

5.2 VLAN transport

If you have 4 VLANs (having 802.1Q_ID: 1, 2, 3 and 4) and you want to transport all of them over the FEC-ed link, you could issue something like this at the CLI (if you really don't want to use the Menus):

'swt-hp(config)# vlan 1 untagged trk1'
'swt-hp(config)# vlan 2 tagged trk1'
'swt-hp(config)# vlan 3 tagged trk1'
'swt-hp(config)# vlan 4 tagged trk1'

This puts trk1 in all 4 VLANs. The switch uses no tags when transporting VLAN 1 data, BUT HAS TO USE TAGS FOR FRAMES ORIGINATING/DESTINED TO ALL OTHER VLANS.

6. ON CISCO:

6.1 Link aggregation

swt-cisco(config)#interface range fa 0/26-27
swt-cisco(config-if-range)#channel-protocol pagp !this is FEC

6.2 VLAN transport

swt-cisco(config-if-range)#switchport mode trunk
swt-cisco(config-if-range)#switchport trunk encapsulation dot1q
swt-cisco(config-if-range)#switchport trunk native vlan1 !use "Untagged" frames when trunking VLAN1
swt-cisco(config-if-range)#switchport trunk allowed vlan 1-4
swt-cisco(config-if-range)#^Z
swt-cisco# copy ru st

With this setting, if you have VLANs 5,6,7... defined, they will not be carried over the trunk (will be pruned).


Hope this helps

[OLARU Dan]

My friend,
I could not believe you'd be so quick!
Best regards,
Dan

[Ulrik Ivers]

Hi,

Thanks for the VERY detailed information.

My question regards AGGREGATION of two FastEthetrnet Ports between a 9304 and a Cisco switch.

The problem I have is that on the 9304 I don't have the "FEC" option when creating the aggregation trunk. I only have the option "switch" or "server". So the question is wether the "switch" option works with a Cisco switch configured to use FEC.

Extract from configuration:
#trunk switch ethe 2/1 to 2/2

I'm running software version 07.1.10T53 on the 9304 switch.

Regards,
/Ulrik

[Kevin Richter_1]

Ulrik,

I just ran across this older forum posting and saw you did not receive an answer. I suspect your issue is long since resolved, but for the benefit of others I post this reply.

A static trunk ("trunk switch") on an HP ProCurve 9304 will function properly or interoperate with manually configured FEC port trunks on Cisco switches.

The only time port trunking or port aggregation protocols must match on both ends is when a dynamic trunk is being formed (using PAgP within FEC or forming a dynamic LACP trunk). As long as you are staticly defining the trunks on each end, this should work and there is no need for the HP device to support FEC.